{"id":7342,"date":"2026-01-21T12:19:09","date_gmt":"2026-01-21T11:19:09","guid":{"rendered":"https:\/\/q3-energie.de\/pv-firefighter-safety-switch-for-photovoltaic-systems\/"},"modified":"2026-07-20T12:04:51","modified_gmt":"2026-07-20T10:04:51","slug":"pv-firefighter-safety-switch","status":"publish","type":"page","link":"https:\/\/q3-energie.de\/en\/technic\/pv-firefighter-safety-switch\/","title":{"rendered":"PV Firefighter Safety Switch for Photovoltaic Systems"},"content":{"rendered":"\n<div class=\"wp-block-cover alignfull\" style=\"min-height:603px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"600\" class=\"wp-block-cover__image-background wp-image-551 size-full\" alt=\"\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Pillar_Page_Header_Feuerwehrschalter-e1777288994973.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Pillar_Page_Header_Feuerwehrschalter-e1777288994973.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Pillar_Page_Header_Feuerwehrschalter-e1777288994973-300x94.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Pillar_Page_Header_Feuerwehrschalter-e1777288994973-1024x320.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Pillar_Page_Header_Feuerwehrschalter-e1777288994973-768x240.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Pillar_Page_Header_Feuerwehrschalter-e1777288994973-1536x480.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-link-color-background-color has-background-dim-80 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div class=\"wp-block-columns alignfull are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-5b0bc1de wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:65%\">\n<h1 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-large-font-size\" id=\"feuerwehrschalter-pv-generatorfreischaltung-fur-photovoltaikanlagen\">PV Firefighter Switch: PV Generator Disconnection for Photovoltaic Systems<\/h1>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color\" id=\"technische-erklarung-zur-sicheren-generatorfreischaltung-von-pv-anlagen-von-der-dc-stringabschaltung-bis-zur-optionalen-ac-seitigen-abschaltlogik\" style=\"font-size:18px\"><strong>Technical explanation of safe PV generator disconnection \u2013 from DC string disconnection to optional AC-side shutdown logic.<\/strong><\/h2>\n\n\n\n<div style=\"height:9px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons has-custom-font-size has-x-large-font-size is-horizontal is-layout-flex wp-block-buttons-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-50 is-style-primary animated fadeInLeft\"><a class=\"wp-block-button__link has-border-color has-nv-site-bg-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"#was\" style=\"border-width:2px;border-top-left-radius:4px;border-top-right-radius:4px;border-bottom-left-radius:4px;border-bottom-right-radius:4px;padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--20)\">What is a PV firefighter switch? \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-50 is-style-secondary animated fadeInLeft delay-100ms\"><a class=\"wp-block-button__link has-border-color has-nv-site-bg-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"#dcac\" style=\"border-width:2px;border-top-left-radius:4px;border-top-right-radius:4px;border-bottom-left-radius:4px;border-bottom-right-radius:4px;padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--20)\">Combining DC and AC shutdown \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-50 is-style-secondary animated fadeInLeft delay-200ms\"><a class=\"wp-block-button__link has-border-color has-nv-site-bg-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"#abschaltung\" style=\"border-width:2px;border-top-left-radius:4px;border-top-right-radius:4px;border-bottom-left-radius:4px;border-bottom-right-radius:4px;padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--20)\">How can a PV system be disconnected safely? \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-50 is-style-primary animated fadeInLeft delay-500ms\"><a class=\"wp-block-button__link has-border-color has-nv-site-bg-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"#normen\" style=\"border-width:2px;border-top-left-radius:4px;border-top-right-radius:4px;border-bottom-left-radius:4px;border-bottom-right-radius:4px;padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--20)\">When is a PV firefighter switch required? \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"400\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_Feld_400px.png\" alt=\"QFire Firefighter Switch Fuses in positive and negative poles Surge protection T1+2 integrated Sheet steel enclosure for industrial environments All cable entries from below \u2014 clean &amp; protected cable handling Made in Germany \u2014 developed &amp; built by Q3 ENERGIE\" class=\"wp-image-320\" style=\"width:400px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_Feld_400px.png 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_Feld_400px-300x300.png 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_Feld_400px-150x150.png 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-rank-math-toc-block q3-toc has-neve-link-color-color has-text-color has-link-color wp-elements-f3bda6e7343f4bd6dd9ee788469c65e1\" id=\"rank-math-toc\"><h2>On this page<\/h2><nav><ul><li class=\"\"><a href=\"#was\">What is a PV Firefighter Safety Switch?<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#warum-benotigen-pv-anlagen-einen-feuerwehrschalter\">Why PV Systems Need Emergency DC Shutdown?<\/a><\/li><li class=\"\"><a href=\"#wie-funktioniert-ein-feuerwehrschalter-in-photovoltaikanlagen\">How Does a PV Firefighter Safety Switch Work?<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#grundprinzip-der-dc-seitigen-abschaltung\">Basic Principle of DC-Side Shutdown<\/a><\/li><li class=\"\"><a href=\"#galvanische-trennung-der-dc-strings\">Galvanic Isolation of PV Strings<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#abschaltung\">Reliable Triggering: \nEmergency Shutdown Mechanisms for PV Firefighter Safety Switches<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#steuerbox-schaltbox\">QFire BIG Control Unit \u2013 Central Control of the Firefighter Safety Switch System<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#cluster-steuerbox-fur-mehrere-dachflachen-und-generatorfelder\">Cluster Control Box for Multiple Roof Areas and Generator Fields<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#die-schaltbox-dc-seitige-stringabschaltung\">The Switching Unit \u2013 DC-Side PV String Disconnection<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#normen\">Standards and Regulations for PV Firefighter Safety Switches<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#was-ist-bei-der-planung-eines-pv-feuerwehrschalters-wichtig\">What is important when planning a PV firefighter switch?<\/a><\/li><li class=\"\"><a href=\"#haufige-fragen-zu-feuerwehrschaltern-fur-pv-anlagen\">Frequently Asked Questions About PV Firefighter Safety Switches<\/a><\/li><li class=\"\"><a href=\"#zeitversetzte-abschaltung-fur-grossanlagen-und-megawatt-projekte\">Time-Delayed Shutdown for Large-Scale and Megawatt PV Systems<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#losungen-fur-unterschiedliche-pv-anlagen\">Solutions for Different Types of Photovoltaic Systems<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#fur-wen-ist-das-q-fire-big-system-ausgelegt\">Who Is the QFire BIG System Designed For?<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#fur-wen-ist-das-q-fire-lite-system-ausgelegt\">Who Is the QFire LITE System Designed For?<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#kombinierte-dc-und-ac-abschaltung-bei-grossen-pv-anlagen\">Combined DC and AC shutdown for large PV systems<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#online-schulung-q-fire-feuerwehrschalter-pv\">Online Training for the QFire PV Firefighter Safety Switch<\/a><\/li><li class=\"\"><a href=\"#wann-ist-ein-feuerwehrschalter-pflicht\">When is a firefighter switch mandatory?<\/a><\/li><\/ul><\/nav><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 id=\"was\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-dfec14d61f6a3990f8ec6c7a2d3583d3\" style=\"font-size:28px\">What is a PV Firefighter Safety Switch?<\/h2>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0;flex-basis:66.66%\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-6252c8eaabf04972f1518912ea02c4e5 wp-block-paragraph\" style=\"font-size:16px\">A PV firefighter safety switch is a safety device designed to selectively disconnect photovoltaic DC circuits at string level. It is intended to protect firefighters, emergency responders and service personnel, particularly during fires or rescue operations in buildings equipped with photovoltaic systems. <br><br>Because PV modules continuously generate DC voltage when exposed to light, the DC cables between the generator field and the inverter remain live even after the AC side has been switched off.<br>String-level shutdown groups several modules together and disconnects them reliably. As a result, dangerous DC voltages are no longer present from the installation point of the firefighter switch towards the inverter. This principle has proven to be technically robust, cost-effective and practical \u2013 particularly for larger and commercial PV systems.  <br><br>Module-level shutdown systems are used in certain applications but usually involve increased technical effort, additional system complexity and higher costs.<br>Modern firefighter safety switches with string-level disconnection can be integrated into fire protection and PV planning concepts and can be triggered manually or via external control signals such as emergency stop buttons or fire alarm systems. <\/p>\n\n\n\n<div class=\"wp-block-group dc-card has-small-font-size is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-f9ecf503\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h4 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-dec24b9b3cc05057d2a86019d26722f5\" id=\"gezielte-abschaltung-der-dc-stromkreise-auf-string-ebene\" style=\"font-size:18px\">Selective DC string disconnection<\/h4>\n<\/div>\n\n\n\n<div style=\"height:15px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-small-font-size is-nowrap is-layout-flex wp-container-core-group-is-layout-8f761849 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-190c6b65\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h4 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-53e79ee2027169442331f25e1a981fab\" id=\"galvanische-trennung-nach-iec-60947-3\" style=\"font-size:18px\">Galvanic isolation according to IEC 60947-3<\/h4>\n<\/div>\n\n\n\n<div style=\"height:15px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-small-font-size is-nowrap is-layout-flex wp-container-core-group-is-layout-8f761849 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-c889f492\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h4 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-fe28e267273963b43f4e35b8bee858fb\" id=\"schutz-fur-einsatzkrafte\" style=\"font-size:18px\">Protection for firefighters and emergency responders<\/h4>\n<\/div>\n\n\n\n<div style=\"height:15px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-small-font-size is-nowrap is-layout-flex wp-container-core-group-is-layout-8f761849 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-57440fbd\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h4 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-3b08ecbf087e9c3dfc9f3c7b3724fa47\" id=\"automatische-oder-manuelle-auslosung\" style=\"font-size:18px\">Automatic or manual emergency shutdown<\/h4>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 id=\"moderne-systeme-wie-der-q-fire-feuerwehrschalter-pv-ermoglichen-eine-automatische-oder-manuelle-auslosung-und-erfullen-die-anforderungen-der-iec-60947-3-fur-eine-sichere-generatorfreischaltung\" class=\"wp-block-heading dc-card has-neve-text-color-color has-text-color has-background has-link-color wp-elements-d6a171bdce88c18fca9f00567d9b31eb\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-style:none;border-right-width:0px;border-left-color:var(--wp--preset--color--neve-text-color);border-left-width:1px;background-color:#f5f6f79e;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\"><strong>Modern systems such as the QFire PV firefighter safety switch support automatic and manual emergency shutdown and are designed for safe PV generator disconnection according to IEC 60947-3.<\/strong><\/h4>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top dc-card has-nv-light-bg-background-color has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-width:1px;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:33.33%\">\n<h3 id=\"feuerwehrschalter-pv-kurz-erklart\" class=\"wp-block-heading\">PV firefighter switch \u2013 briefly explained<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A firefighter switch for photovoltaic systems disconnects PV strings on the DC side and galvanically isolates them from the inverter in the event of activation. The aim is to de-energise the DC cables from the installation point of the switching unit towards the inverter. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">PV modules can continue to generate voltage when exposed to light. Generator-side disconnection therefore reduces dangerous DC voltages inside the building or along long cable routes. Modern systems such as QFire are designed according to IEC 60947-3 and can be triggered automatically, manually or via external control signals, depending on the system design. <\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<figure class=\"wp-block-image size-full q3-duotone\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"400\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px.webp\" alt=\"QFire Firefighter Switch for 8 Strings with Surge Protection T1+2\" class=\"wp-image-314\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px-150x150.webp 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/figure>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group alignfull has-neve-text-color-background-color has-background\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-container-core-group-is-layout-a48333fe wp-block-group-is-layout-constrained\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-f51692ee70f0216c5e8b443dd602d901\" id=\"warum-benotigen-pv-anlagen-einen-feuerwehrschalter\" style=\"font-size:28px\">Why PV Systems Need Emergency DC Shutdown?<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-text-color-background-color has-background is-layout-flex wp-container-core-columns-is-layout-f54850f0 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);flex-basis:66%\">\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color wp-block-paragraph\" style=\"font-size:16px\">Photovoltaic systems can generate DC voltages of up to 1,500 V. Even when the inverter is switched off, the DC string cables may remain live.<br><br>In emergency situations, this can:<\/p>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-acf9466451e186242576f78f3053e2be is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-21e3f7a1\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-8dd4439524939d9017cfd0230d1dca2f wp-block-paragraph\" style=\"font-size:16px\"><strong>Complicate rescue operations<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-5e723766180e54c396306f502e952933 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-918d59c3\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-e116659c2199e1eb76ece9ae58e49306 wp-block-paragraph\" style=\"font-size:16px\"><strong>Endanger firefighters and emergency responders<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-b5d766597ccfb2f68549a6a98e86243c is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-607a1ad2\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-470317fc74667d58c21d27de8fa1c72f wp-block-paragraph\" style=\"font-size:16px\"><strong>Delay firefighting operations<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:15px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color wp-block-paragraph\" style=\"font-size:16px\">A firefighter safety switch enables galvanic disconnection of the PV strings directly at the building entry point or close to the roof entry.<\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-3e2376e5b65bfd6b1f328bc27c88123b wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-top-color:var(--nv-c-2);border-right-color:var(--nv-c-2);border-bottom-color:var(--nv-c-2);border-left-color:var(--nv-text-dark-bg);border-left-width:1px;padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40)\"><strong>The challenge of DC voltage: photovoltaic systems continuously generate voltage when exposed to light. <br>Disconnecting the AC side alone does not automatically make a PV system DC-safe.<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:33%\">\n<figure class=\"wp-block-image size-full is-resized has-custom-border q3-duotone\"><a href=\"https:\/\/q3-energie.de\/en\/lasertechnik-kilgenstein-relies-on-modern-pv-technology\/\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz.webp\" alt=\"QFire PV firefighter safety switch installed in practice for safe PV generator disconnection and emergency DC shutdown\" class=\"wp-image-3815\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;width:500px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz-300x225.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz-768x576.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/a><\/figure>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<figure class=\"wp-block-image size-full is-resized has-custom-border q3-duotone\"><a href=\"https:\/\/q3-energie.de\/en\/qfire-firefighter-switch-for-a-4-7-mwp-pv-system-at-ladenburger\/\"><img loading=\"lazy\" decoding=\"async\" width=\"383\" height=\"383\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/QFire-Feuerwehrschalter-fuer-47-MWp.webp\" alt=\"Firefighter switches QFire for 4,7 MWp\" class=\"wp-image-5983\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;width:500px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/QFire-Feuerwehrschalter-fuer-47-MWp.webp 383w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/QFire-Feuerwehrschalter-fuer-47-MWp-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/QFire-Feuerwehrschalter-fuer-47-MWp-150x150.webp 150w\" sizes=\"auto, (max-width: 383px) 100vw, 383px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide\" id=\"wie-funktioniert-ein-feuerwehrschalter-in-photovoltaikanlagen\" style=\"font-size:28px\">How Does a PV Firefighter Safety Switch Work?<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide are-vertically-aligned-center has-nv-text-dark-bg-background-color has-background is-layout-flex wp-container-core-columns-is-layout-f54850f0 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">A firefighter safety switch disconnects the PV strings automatically or manually from the inverter by galvanic isolation in emergency situations. Typical system components include: <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\"><strong>[1] Switch Boxes installed close to the roof entry point<br>[2] Control Box located in the inverter area<br>[3] Optional external emergency stop and interface to the fire alarm system<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">Optional components include:<br>\u25a0 integration of a fire alarm system<br>\u25a0 integrated surge protection<br>\u25a0 integrated fuses in the positive and\/or negative pole<br>\u25a0 cluster technology for multiple roof areas<br>\u25a0 integration into an AC-side shutdown concept <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">In the event of shutdown, all PV strings are galvanically isolated so that the cables between the firefighter safety switch and the inverter become de-energised.<br><br><\/p>\n\n\n\n<h4 id=\"diese-trennung-ermoglicht-eine-flexible-anpassung-an-unterschiedliche-anlagenkonzepte-von-kleinen-gewerbeanlagen-bis-hin-zu-grossen-pv-grossanlagen-mit-mehreren-generatorfeldern\" class=\"wp-block-heading dc-card has-neve-text-color-color has-text-color has-background has-link-color wp-elements-f608da87349847b3e188df1f0aa38b4f\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-style:none;border-right-width:0px;border-left-color:var(--wp--preset--color--neve-text-color);border-left-width:1px;background-color:#f5f6f79e;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\"><strong>Flexible integration for different photovoltaic system concepts \u2013 from small commercial installations to large-scale PV systems with multiple generator fields.<\/strong><\/h4>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\"><div class=\"wp-block-image q3-duotone\">\n<figure class=\"aligncenter size-full has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"794\" height=\"794\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Aufbau-des-QFire-Feuerwehrschalter-Systems.webp\" alt=\"Structure of the QFire PV Firefighter Safety Switch System\" class=\"wp-image-734\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Aufbau-des-QFire-Feuerwehrschalter-Systems.webp 794w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Aufbau-des-QFire-Feuerwehrschalter-Systems-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Aufbau-des-QFire-Feuerwehrschalter-Systems-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Aufbau-des-QFire-Feuerwehrschalter-Systems-768x768.webp 768w\" sizes=\"auto, (max-width: 794px) 100vw, 794px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-1\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);min-height:600px;aspect-ratio:unset;\"><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-link-color-background-color has-background-dim-90 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left alignwide has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-ded7e1b74a677b1b60ca9ba7e4f141da\" id=\"technische-anforderungen-an-moderne-feuerwehrschalter-pv\" style=\"font-size:28px\">Technical Requirements for Modern PV Firefighter Safety Switches<\/h2>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-flow wp-block-group-is-layout-flow\">\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:0;padding-left:0;flex-basis:400px\"><div class=\"wp-block-image q3-duotone\">\n<figure class=\"aligncenter size-medium is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/Feuerwehrschalter-QFire-24-Strings-mit-Ueberspannungsschutz-300x300.webp\" alt=\"Firefighter switches QFire 24 strings with surge protection\" class=\"wp-image-5680\" style=\"width:300px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/Feuerwehrschalter-QFire-24-Strings-mit-Ueberspannungsschutz-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/Feuerwehrschalter-QFire-24-Strings-mit-Ueberspannungsschutz-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/Feuerwehrschalter-QFire-24-Strings-mit-Ueberspannungsschutz.webp 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:50%\">\n<p class=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-4ea7842c9a5161aaec00ec0015adfbab wp-block-paragraph\" style=\"font-size:16px\"><strong>Modern firefighter safety switch systems must meet a wide range of technical requirements:<\/strong><\/p>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-fc77ee2f6767e418526aaf25c94f531d is-nowrap is-layout-flex wp-container-core-group-is-layout-bd7ac72f wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-3d51be00\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-a2da5630f42b5be50b12f738280f688c wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong>Certified according to IEC 60947-3<\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-29e88b4258f420e73388f7dac761ed74 is-nowrap is-layout-flex wp-container-core-group-is-layout-bd7ac72f wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-7c8594f8\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-a95982a14d5537d9d02338dc605ac93c wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong>System voltages up to 1,500 V DC<\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-8c0484e771df5ee19bc81d41ac04e744 is-nowrap is-layout-flex wp-container-core-group-is-layout-bd7ac72f wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-57c51216\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-3197b81e824394772b99ac6670fd4b42 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong>String currents up to 20 A per string<\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-f0480082710fc0e94ca398024b66999c is-nowrap is-layout-flex wp-container-core-group-is-layout-bd7ac72f wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-160c7974\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-6be319f55dc41befe4d71bc8151fb2b1 wp-block-paragraph\" style=\"font-size:16px\">Safe shutdown without arcing &#8211; through galvanic isolation<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-acacd3ab949179d8a959823e0e46cf64 is-nowrap is-layout-flex wp-container-core-group-is-layout-bd7ac72f wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-5d2f242c\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-609b86d9139e0bf75d9393696965c7fc wp-block-paragraph\" style=\"font-size:16px\"><strong>Robust enclosures for outdoor installation (IP66\/IP67)<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-0037a15450dbda2b3805b1a68d4d95f4 is-nowrap is-layout-flex wp-container-core-group-is-layout-bd7ac72f wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-d9903123\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-f2afe6ce307bda7e9fcaf9a6f789defe wp-block-paragraph\" style=\"font-size:16px\"><strong>Integration of surge protection and\/or string fuses<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div>\n<\/div>\n<\/div><\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column dc-card is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center\" id=\"q-3-feuerwehrschalter-pv-q-fire-lite-big-auf-einen-blick\">Q3 PV firefighter switch QFire LITE | BIG at a glance<\/h3>\n\n\n\n<figure class=\"wp-block-table is-style-stripes ref-project-card\"><table><thead><tr><th>Requirement<\/th><th class=\"has-text-align-center\" data-align=\"center\">QFire LITE<\/th><th class=\"has-text-align-center\" data-align=\"center\">QFire BIG<\/th><\/tr><\/thead><tbody><tr><td><strong>System type<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">smaller to medium-sized PV systems<\/td><td class=\"has-text-align-center\" data-align=\"center\">larger commercial PV systems<\/td><\/tr><tr><td><strong>System design<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">compact standard solution<\/td><td class=\"has-text-align-center\" data-align=\"center\">central Control Box with Switch Boxes<\/td><\/tr><tr><td><strong>Expandability<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">standardised, not cascadable<\/td><td class=\"has-text-align-center\" data-align=\"center\">modular and cascadable<\/td><\/tr><tr><td><strong>Triggering<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\"><br>e.g. grid failure, external signal, emergency stop<\/td><td class=\"has-text-align-center\" data-align=\"center\">grid failure, emergency stop, Control Box, FAS\/FACP<\/td><\/tr><tr><td><strong>Typical application<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">simple rooftop systems, smaller commercial systems<\/td><td class=\"has-text-align-center\" data-align=\"center\">large rooftops, multiple roof areas, public buildings, industrial sites<\/td><\/tr><tr><td><strong>Planning<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">standardised<\/td><td class=\"has-text-align-center\" data-align=\"center\">project-specific<\/td><\/tr><tr><td><strong>Link<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\"><a href=\"https:\/\/q3-energie.de\/en\/products\/qfire-lite-firefighter-switch\/\" data-type=\"page\" data-id=\"1049\">View QFire LITE for smaller PV systems \u2192<\/a><\/td><td class=\"has-text-align-center\" data-align=\"center\"><a href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\" data-type=\"page\" data-id=\"1046\">View QFire BIG for large PV systems \u2192<\/a><\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-2\" style=\"min-height:600px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-465 size-full\" alt=\"\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-80 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-7898c23e wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--70);padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50)\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:0;padding-left:var(--wp--preset--spacing--70);flex-basis:50%\">\n<h2 id=\"grundprinzip-der-dc-seitigen-abschaltung\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-fd78ed78605d9ede0f95e5a07503ad5b\" style=\"border-style:none;border-width:0px;font-size:28px\">Basic Principle of DC-Side Shutdown<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-76a231cadb62ee9608ecbd73263cf579 wp-block-paragraph\" style=\"font-size:16px\">In photovoltaic systems, DC voltage is generated directly within the PV generator. This means that DC cables can remain critical even when only the AC supply has been disconnected.<br>QFire addresses this issue by disconnecting the PV strings at string level close to the roof entry point or near the PV modules. The goal is to safely de-energise the cables between the switching unit and the inverter in the event of emergency shutdown.   <\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-ba2e94a6478feb044537cdabcbb178bb wp-block-paragraph\"><strong>Advantages of this principle<\/strong><\/p>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-34caee26\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M1096.233,698.227c0-108.2-88.028-196.229-196.229-196.229c-108.205,0-196.234,88.029-196.234,196.229 v74.779H571.518v226.107c1.825,179.273,149.183,325.127,328.487,325.127s326.658-145.854,328.478-325.445V773.006h-132.249V698.227 z M1165.753,835.734v162.74c-1.47,145.039-120.684,263.037-265.749,263.037s-264.283-117.998-265.758-262.717V835.734H1165.753z M766.5,773.006v-74.779c0-73.611,59.889-133.5,133.504-133.5c73.611,0,133.5,59.889,133.5,133.5v74.779H766.5z\"><\/path><path d=\"M1668.854,759.284c-58.126-318.375-309.768-570.017-628.138-628.141 C1031.553,61.639,971.966,7.808,900,7.808S768.442,61.642,759.28,131.146C440.91,189.271,189.268,440.914,131.146,759.284 c-69.507,9.162-123.34,68.754-123.34,140.72c0,71.968,53.833,131.551,123.34,140.713 c58.121,318.371,309.763,570.008,628.134,628.135c9.162,69.502,68.754,123.34,140.72,123.34s131.553-53.834,140.716-123.34 c318.37-58.122,570.017-309.764,628.138-628.13c69.507-9.163,123.34-68.75,123.34-140.718 C1792.193,828.038,1738.36,768.446,1668.854,759.284z M900,70.537c33.898,0,62.808,21.432,74.109,51.424 c3.27,8.672,5.142,18.025,5.142,27.827c0,12.525-3.001,24.335-8.195,34.876c-12.93,26.241-39.88,44.382-71.056,44.382 c-31.181,0-58.13-18.141-71.06-44.382c-5.198-10.541-8.196-22.351-8.196-34.876c0-9.801,1.873-19.154,5.142-27.827 C837.188,91.969,866.098,70.537,900,70.537z M121.962,974.115c-29.995-11.306-51.427-40.211-51.427-74.111 c0-33.902,21.432-62.812,51.427-74.114c8.672-3.269,18.027-5.142,27.829-5.142c12.523,0,24.333,2.998,34.874,8.196 c26.236,12.93,44.377,39.879,44.377,71.06c0,31.179-18.141,58.123-44.377,71.058c-10.541,5.19-22.351,8.191-34.874,8.191 C139.989,979.253,130.634,977.381,121.962,974.115z M900,1729.462c-33.902,0-62.812-21.432-74.114-51.427 c-3.269-8.672-5.142-18.027-5.142-27.828c0-12.523,2.998-24.334,8.196-34.875c12.93-26.24,39.879-44.377,71.06-44.377 c31.176,0,58.126,18.137,71.056,44.377c5.194,10.541,8.195,22.352,8.195,34.875c0,9.801-1.872,19.156-5.142,27.828 C962.808,1708.03,933.898,1729.462,900,1729.462z M1034.927,1606.087c-18.605-56.747-72.04-97.86-134.927-97.86 s-116.326,41.113-134.931,97.86c-288.367-54.993-516.166-282.788-571.159-571.159c56.748-18.604,97.861-72.039,97.861-134.924 c0-62.887-41.113-116.326-97.861-134.931c54.993-288.371,282.792-516.17,571.159-571.163 c18.605,56.752,72.044,97.865,134.931,97.865s116.321-41.113,134.927-97.865c288.371,54.993,516.17,282.792,571.163,571.163 c-56.752,18.605-97.865,72.044-97.865,134.931c0,62.885,41.113,116.319,97.865,134.924 C1551.097,1323.299,1323.298,1551.094,1034.927,1606.087z M1678.038,974.115c-8.673,3.266-18.023,5.138-27.824,5.138 c-12.528,0-24.338-3.001-34.879-8.191c-26.24-12.935-44.382-39.879-44.382-71.058c0-31.176,18.142-58.126,44.382-71.06 c10.541-5.198,22.351-8.196,34.879-8.196c9.801,0,19.151,1.873,27.824,5.142c29.995,11.298,51.427,40.212,51.427,74.114 C1729.465,933.904,1708.033,962.818,1678.038,974.115z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-43087be1facc71de792dba9a884e6e28 wp-block-paragraph\" style=\"font-size:16px\"><strong>DC-side shutdown directly within the PV system<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-62743d36\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M1096.233,698.227c0-108.2-88.028-196.229-196.229-196.229c-108.205,0-196.234,88.029-196.234,196.229 v74.779H571.518v226.107c1.825,179.273,149.183,325.127,328.487,325.127s326.658-145.854,328.478-325.445V773.006h-132.249V698.227 z M1165.753,835.734v162.74c-1.47,145.039-120.684,263.037-265.749,263.037s-264.283-117.998-265.758-262.717V835.734H1165.753z M766.5,773.006v-74.779c0-73.611,59.889-133.5,133.504-133.5c73.611,0,133.5,59.889,133.5,133.5v74.779H766.5z\"><\/path><path d=\"M1668.854,759.284c-58.126-318.375-309.768-570.017-628.138-628.141 C1031.553,61.639,971.966,7.808,900,7.808S768.442,61.642,759.28,131.146C440.91,189.271,189.268,440.914,131.146,759.284 c-69.507,9.162-123.34,68.754-123.34,140.72c0,71.968,53.833,131.551,123.34,140.713 c58.121,318.371,309.763,570.008,628.134,628.135c9.162,69.502,68.754,123.34,140.72,123.34s131.553-53.834,140.716-123.34 c318.37-58.122,570.017-309.764,628.138-628.13c69.507-9.163,123.34-68.75,123.34-140.718 C1792.193,828.038,1738.36,768.446,1668.854,759.284z M900,70.537c33.898,0,62.808,21.432,74.109,51.424 c3.27,8.672,5.142,18.025,5.142,27.827c0,12.525-3.001,24.335-8.195,34.876c-12.93,26.241-39.88,44.382-71.056,44.382 c-31.181,0-58.13-18.141-71.06-44.382c-5.198-10.541-8.196-22.351-8.196-34.876c0-9.801,1.873-19.154,5.142-27.827 C837.188,91.969,866.098,70.537,900,70.537z M121.962,974.115c-29.995-11.306-51.427-40.211-51.427-74.111 c0-33.902,21.432-62.812,51.427-74.114c8.672-3.269,18.027-5.142,27.829-5.142c12.523,0,24.333,2.998,34.874,8.196 c26.236,12.93,44.377,39.879,44.377,71.06c0,31.179-18.141,58.123-44.377,71.058c-10.541,5.19-22.351,8.191-34.874,8.191 C139.989,979.253,130.634,977.381,121.962,974.115z M900,1729.462c-33.902,0-62.812-21.432-74.114-51.427 c-3.269-8.672-5.142-18.027-5.142-27.828c0-12.523,2.998-24.334,8.196-34.875c12.93-26.24,39.879-44.377,71.06-44.377 c31.176,0,58.126,18.137,71.056,44.377c5.194,10.541,8.195,22.352,8.195,34.875c0,9.801-1.872,19.156-5.142,27.828 C962.808,1708.03,933.898,1729.462,900,1729.462z M1034.927,1606.087c-18.605-56.747-72.04-97.86-134.927-97.86 s-116.326,41.113-134.931,97.86c-288.367-54.993-516.166-282.788-571.159-571.159c56.748-18.604,97.861-72.039,97.861-134.924 c0-62.887-41.113-116.326-97.861-134.931c54.993-288.371,282.792-516.17,571.159-571.163 c18.605,56.752,72.044,97.865,134.931,97.865s116.321-41.113,134.927-97.865c288.371,54.993,516.17,282.792,571.163,571.163 c-56.752,18.605-97.865,72.044-97.865,134.931c0,62.885,41.113,116.319,97.865,134.924 C1551.097,1323.299,1323.298,1551.094,1034.927,1606.087z M1678.038,974.115c-8.673,3.266-18.023,5.138-27.824,5.138 c-12.528,0-24.338-3.001-34.879-8.191c-26.24-12.935-44.382-39.879-44.382-71.058c0-31.176,18.142-58.126,44.382-71.06 c10.541-5.198,22.351-8.196,34.879-8.196c9.801,0,19.151,1.873,27.824,5.142c29.995,11.298,51.427,40.212,51.427,74.114 C1729.465,933.904,1708.033,962.818,1678.038,974.115z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-d738256cfd7cf68105ebc9c1c396b9f0 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Galvanic isolation of all PV strings<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-88af2ede\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M1096.233,698.227c0-108.2-88.028-196.229-196.229-196.229c-108.205,0-196.234,88.029-196.234,196.229 v74.779H571.518v226.107c1.825,179.273,149.183,325.127,328.487,325.127s326.658-145.854,328.478-325.445V773.006h-132.249V698.227 z M1165.753,835.734v162.74c-1.47,145.039-120.684,263.037-265.749,263.037s-264.283-117.998-265.758-262.717V835.734H1165.753z M766.5,773.006v-74.779c0-73.611,59.889-133.5,133.504-133.5c73.611,0,133.5,59.889,133.5,133.5v74.779H766.5z\"><\/path><path d=\"M1668.854,759.284c-58.126-318.375-309.768-570.017-628.138-628.141 C1031.553,61.639,971.966,7.808,900,7.808S768.442,61.642,759.28,131.146C440.91,189.271,189.268,440.914,131.146,759.284 c-69.507,9.162-123.34,68.754-123.34,140.72c0,71.968,53.833,131.551,123.34,140.713 c58.121,318.371,309.763,570.008,628.134,628.135c9.162,69.502,68.754,123.34,140.72,123.34s131.553-53.834,140.716-123.34 c318.37-58.122,570.017-309.764,628.138-628.13c69.507-9.163,123.34-68.75,123.34-140.718 C1792.193,828.038,1738.36,768.446,1668.854,759.284z M900,70.537c33.898,0,62.808,21.432,74.109,51.424 c3.27,8.672,5.142,18.025,5.142,27.827c0,12.525-3.001,24.335-8.195,34.876c-12.93,26.241-39.88,44.382-71.056,44.382 c-31.181,0-58.13-18.141-71.06-44.382c-5.198-10.541-8.196-22.351-8.196-34.876c0-9.801,1.873-19.154,5.142-27.827 C837.188,91.969,866.098,70.537,900,70.537z M121.962,974.115c-29.995-11.306-51.427-40.211-51.427-74.111 c0-33.902,21.432-62.812,51.427-74.114c8.672-3.269,18.027-5.142,27.829-5.142c12.523,0,24.333,2.998,34.874,8.196 c26.236,12.93,44.377,39.879,44.377,71.06c0,31.179-18.141,58.123-44.377,71.058c-10.541,5.19-22.351,8.191-34.874,8.191 C139.989,979.253,130.634,977.381,121.962,974.115z M900,1729.462c-33.902,0-62.812-21.432-74.114-51.427 c-3.269-8.672-5.142-18.027-5.142-27.828c0-12.523,2.998-24.334,8.196-34.875c12.93-26.24,39.879-44.377,71.06-44.377 c31.176,0,58.126,18.137,71.056,44.377c5.194,10.541,8.195,22.352,8.195,34.875c0,9.801-1.872,19.156-5.142,27.828 C962.808,1708.03,933.898,1729.462,900,1729.462z M1034.927,1606.087c-18.605-56.747-72.04-97.86-134.927-97.86 s-116.326,41.113-134.931,97.86c-288.367-54.993-516.166-282.788-571.159-571.159c56.748-18.604,97.861-72.039,97.861-134.924 c0-62.887-41.113-116.326-97.861-134.931c54.993-288.371,282.792-516.17,571.159-571.163 c18.605,56.752,72.044,97.865,134.931,97.865s116.321-41.113,134.927-97.865c288.371,54.993,516.17,282.792,571.163,571.163 c-56.752,18.605-97.865,72.044-97.865,134.931c0,62.885,41.113,116.319,97.865,134.924 C1551.097,1323.299,1323.298,1551.094,1034.927,1606.087z M1678.038,974.115c-8.673,3.266-18.023,5.138-27.824,5.138 c-12.528,0-24.338-3.001-34.879-8.191c-26.24-12.935-44.382-39.879-44.382-71.058c0-31.176,18.142-58.126,44.382-71.06 c10.541-5.198,22.351-8.196,34.879-8.196c9.801,0,19.151,1.873,27.824,5.142c29.995,11.298,51.427,40.212,51.427,74.114 C1729.465,933.904,1708.033,962.818,1678.038,974.115z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-37eb163aa8ca1146f6163a45d3738c5f wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong>Reduction of dangerous DC voltage during fire emergencies<\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-0d2bb2f4\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M1096.233,698.227c0-108.2-88.028-196.229-196.229-196.229c-108.205,0-196.234,88.029-196.234,196.229 v74.779H571.518v226.107c1.825,179.273,149.183,325.127,328.487,325.127s326.658-145.854,328.478-325.445V773.006h-132.249V698.227 z M1165.753,835.734v162.74c-1.47,145.039-120.684,263.037-265.749,263.037s-264.283-117.998-265.758-262.717V835.734H1165.753z M766.5,773.006v-74.779c0-73.611,59.889-133.5,133.504-133.5c73.611,0,133.5,59.889,133.5,133.5v74.779H766.5z\"><\/path><path d=\"M1668.854,759.284c-58.126-318.375-309.768-570.017-628.138-628.141 C1031.553,61.639,971.966,7.808,900,7.808S768.442,61.642,759.28,131.146C440.91,189.271,189.268,440.914,131.146,759.284 c-69.507,9.162-123.34,68.754-123.34,140.72c0,71.968,53.833,131.551,123.34,140.713 c58.121,318.371,309.763,570.008,628.134,628.135c9.162,69.502,68.754,123.34,140.72,123.34s131.553-53.834,140.716-123.34 c318.37-58.122,570.017-309.764,628.138-628.13c69.507-9.163,123.34-68.75,123.34-140.718 C1792.193,828.038,1738.36,768.446,1668.854,759.284z M900,70.537c33.898,0,62.808,21.432,74.109,51.424 c3.27,8.672,5.142,18.025,5.142,27.827c0,12.525-3.001,24.335-8.195,34.876c-12.93,26.241-39.88,44.382-71.056,44.382 c-31.181,0-58.13-18.141-71.06-44.382c-5.198-10.541-8.196-22.351-8.196-34.876c0-9.801,1.873-19.154,5.142-27.827 C837.188,91.969,866.098,70.537,900,70.537z M121.962,974.115c-29.995-11.306-51.427-40.211-51.427-74.111 c0-33.902,21.432-62.812,51.427-74.114c8.672-3.269,18.027-5.142,27.829-5.142c12.523,0,24.333,2.998,34.874,8.196 c26.236,12.93,44.377,39.879,44.377,71.06c0,31.179-18.141,58.123-44.377,71.058c-10.541,5.19-22.351,8.191-34.874,8.191 C139.989,979.253,130.634,977.381,121.962,974.115z M900,1729.462c-33.902,0-62.812-21.432-74.114-51.427 c-3.269-8.672-5.142-18.027-5.142-27.828c0-12.523,2.998-24.334,8.196-34.875c12.93-26.24,39.879-44.377,71.06-44.377 c31.176,0,58.126,18.137,71.056,44.377c5.194,10.541,8.195,22.352,8.195,34.875c0,9.801-1.872,19.156-5.142,27.828 C962.808,1708.03,933.898,1729.462,900,1729.462z M1034.927,1606.087c-18.605-56.747-72.04-97.86-134.927-97.86 s-116.326,41.113-134.931,97.86c-288.367-54.993-516.166-282.788-571.159-571.159c56.748-18.604,97.861-72.039,97.861-134.924 c0-62.887-41.113-116.326-97.861-134.931c54.993-288.371,282.792-516.17,571.159-571.163 c18.605,56.752,72.044,97.865,134.931,97.865s116.321-41.113,134.927-97.865c288.371,54.993,516.17,282.792,571.163,571.163 c-56.752,18.605-97.865,72.044-97.865,134.931c0,62.885,41.113,116.319,97.865,134.924 C1551.097,1323.299,1323.298,1551.094,1034.927,1606.087z M1678.038,974.115c-8.673,3.266-18.023,5.138-27.824,5.138 c-12.528,0-24.338-3.001-34.879-8.191c-26.24-12.935-44.382-39.879-44.382-71.058c0-31.176,18.142-58.126,44.382-71.06 c10.541-5.198,22.351-8.196,34.879-8.196c9.801,0,19.151,1.873,27.824,5.142c29.995,11.298,51.427,40.212,51.427,74.114 C1729.465,933.904,1708.033,962.818,1678.038,974.115z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-92997509a138f494a1fbf36398742222 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong><strong>Shutdown close to the roof entry point or near the PV modules<\/strong><\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"border-style:none;border-width:0px;padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);flex-basis:50%\">\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"447\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Abschaltung_generatornah_600px.webp\" alt=\"PV firefighter safety switch with generator-side DC shutdown close to the PV generator\" class=\"wp-image-754\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Abschaltung_generatornah_600px.webp 600w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Abschaltung_generatornah_600px-300x224.webp 300w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"dc-card has-neve-text-color-color has-nv-light-bg-background-color has-text-color has-background has-link-color wp-elements-6fd44b6327ddcec2f552abe358b46abf wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-width:1px;font-size:16px\">The QFire PV firefighter safety switch is designed for safe DC-side shutdown of photovoltaic systems. Unlike purely AC-side shutdown concepts, the DC voltage generated by the PV system is disconnected directly at the source.<br>This helps prevent dangerous DC voltage from continuing to enter the building through the string cables during fire or emergency situations.  <br><br>Shutdown is achieved through galvanic isolation of all active conductors (positive and negative) for each PV string. After activation, the PV strings are de-energised so that no dangerous DC voltage remains on the cables or at the inverter inputs. <\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\"><img loading=\"lazy\" decoding=\"async\" width=\"1058\" height=\"800\" class=\"wp-block-cover__image-background wp-image-812 size-full\" alt=\"Cluster Steuerbox f\u00fcr mehrere Generatorfl\u00e4chen\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp 1058w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-300x227.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-1024x774.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-768x581.webp 768w\" sizes=\"auto, (max-width: 1058px) 100vw, 1058px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-b7217e4437731cda96128230371ef859 is-layout-flex wp-container-core-columns-is-layout-52356811 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--70);padding-right:0;padding-bottom:var(--wp--preset--spacing--70);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-center has-nv-site-bg-color has-text-color has-link-color wp-elements-9763ece04482c848afecd96bd746a522 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);flex-basis:50%\">\n<h2 id=\"galvanische-trennung-der-dc-strings\" class=\"wp-block-heading has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-e14309389fcfc5141c5660150b3a40cc\" style=\"border-style:none;border-width:0px;font-size:28px\">Galvanic Isolation of PV Strings<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">In the event of emergency shutdown, the QFire PV firefighter safety switch disconnects all connected PV strings galvanically and on both poles according to IEC 60947-3. Both the positive and negative conductors of each string are reliably isolated from the inverter to maximise safety during fire and emergency situations.<\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-ac28f1a1eabb58f8b7314e62de598e46 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-95a6e367\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-7636bc46229120a59bb808e7a151d551\" id=\"klare-abgrenzung-zu-motorschalter-losungen\" style=\"font-size:16px\"><strong><strong>Clear distinction from motor switch solutions<\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-0e54758b83a06356ac6da66e2eacc8d2 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-32d88911\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-418bf6f4d7a609f43760e1e69fce035d\" id=\"zweipolige-trennung-von-plus-und-minus\" style=\"font-size:16px\"><strong><strong><strong>Two-pole disconnection of positive and negative conductors<\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-a0e802e745891f64c056950407397224 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-ec952f0e\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-ff353200d006b1bfd4db43533dba9f12\" id=\"sichere-unterbrechung-der-dc-verbindung\" style=\"font-size:16px\"><strong><strong><strong>Safe interruption of the DC connection<\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card undefined has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-de63db8f9f49a13d023b4250c4c83476 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-92bb0aa1\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-fa53e3bec58daf2f559bd571cc57dfca\" id=\"dc-seitige-abschaltung-direkt-am-string-statt-nur-netzseitiger-trennung\" style=\"font-size:16px\"><strong><strong><strong>DC-side shutdown directly at string level instead of AC-side isolation only<\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-605708f812c63adb8c57fdb57af0b16d is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-23e73db0\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-6fda9897fea1c58807f585356006b98e\" id=\"geeignet-fur-systemspannungen-bis-1-500-v-dc-und-bis-zu-20-a-pro-string\" style=\"font-size:16px\"><strong><strong><strong>Suitable for system voltages up to 1,500 V DC and string currents up to 20 A<\/strong><\/strong><\/strong><\/h3>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);flex-basis:50%\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"125\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/galvanische-Trennung-300x125.webp\" alt=\"Galvanic isolation of PV strings using the QFire firefighter safety switch\" class=\"wp-image-4725\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/galvanische-Trennung-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/05\/galvanische-Trennung.webp 600w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-f33dc45f93b3845f8ea74d211c6ff1d1 wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-color:var(--wp--preset--color--nv-text-dark-bg);border-left-width:1px;background-color:#ffffff08;font-size:16px\">Galvanic isolation completely interrupts the electrical connection between the PV generator and the inverter. After activation, the cables downstream of the QFire switching unit are de-energised. This principle significantly reduces DC-related hazards during fire emergencies and helps maximise safety for firefighters, emergency responders and service personnel.  <br><br>This shutdown principle significantly improves safety during fire and emergency situations by reliably interrupting dangerous DC voltage. At the same time, galvanic isolation remains effective regardless of the PV system configuration, string length or the number of connected generator fields. <\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 id=\"abschaltung\" class=\"wp-block-heading\">Safe triggering in the event of fire or fault:<br>Shutdown mechanisms for PV firefighter switches in emergency and fault scenarios<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 id=\"mehrere-auslosewege-sorgen-dafur-dass-die-abschaltung-im-ernstfall-zuverlassig-erfolgt-manuell-automatisch-oder-extern-angesteuert\" class=\"wp-block-heading\">Multiple triggering methods ensure reliable shutdown in emergency situations \u2014 manually, automatically or via external control signals.<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">The QFire firefighter safety switch can be triggered in several different ways. In addition to manual shutdown via the control unit or external emergency stop buttons, the system also responds automatically to defined fault conditions.  <br><br>In the event of grid failure or undervoltage, the relays automatically open and galvanically disconnect the connected PV strings from the inverter. This ensures that the safety function remains active even if the supply voltage fails.<br>The system also detects cable breakage or voltage drops within the control circuit and automatically initiates a safe shutdown.  <\/p>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-bottom is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-11338623\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,868.536c-113.664,0-206.139,92.473-206.139,206.145c0,72.752,38.923,140.217,100.683,177.107v167.979 h210.914v-167.979c61.764-36.891,100.689-104.355,100.689-177.107C1106.146,961.009,1013.669,868.536,900,868.536z M960.627,1204.401l-18.129,8.493v143.914h-84.996v-143.914l-18.129-8.493c-50.148-23.487-82.554-74.403-82.554-129.721 c0-78.952,64.232-143.185,143.181-143.185c78.952,0,143.189,64.232,143.189,143.185 C1043.189,1129.998,1010.782,1180.914,960.627,1204.401z\"><\/path><path d=\"M1306.793,621.365V406.939c-1.094-107.793-43.891-208.955-120.511-284.855 C1109.604,46.13,1007.934,4.301,899.996,4.301c-107.933,0-209.604,41.83-286.273,117.788 c-76.617,75.896-119.413,177.057-120.507,285.166v112.333h62.958V407.571c1.898-187.646,156.137-340.313,343.822-340.313 c187.696,0,341.942,152.667,343.839,339.996v214.11H888.52H192.564v474.124c1.906,187.453,76.336,363.382,209.578,495.369 C535.485,1722.948,712.296,1795.7,900.004,1795.7c187.708,0,364.519-72.752,497.863-204.843 c133.242-131.987,207.668-307.916,209.568-495.693V621.365H1306.793z M1544.477,1094.848 c-3.561,351.735-292.671,637.894-644.472,637.894c-351.796,0-640.912-286.158-644.482-637.577v-410.84h237.693h813.578h237.684 V1094.848z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-260311e0fc99905aa26f833b773cadac\" id=\"manuelle-abschaltung-uber-hauptschalter\" style=\"font-size:16px\"><strong>Manual shutdown via main switch<\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-b0319275\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,868.536c-113.664,0-206.139,92.473-206.139,206.145c0,72.752,38.923,140.217,100.683,177.107v167.979 h210.914v-167.979c61.764-36.891,100.689-104.355,100.689-177.107C1106.146,961.009,1013.669,868.536,900,868.536z M960.627,1204.401l-18.129,8.493v143.914h-84.996v-143.914l-18.129-8.493c-50.148-23.487-82.554-74.403-82.554-129.721 c0-78.952,64.232-143.185,143.181-143.185c78.952,0,143.189,64.232,143.189,143.185 C1043.189,1129.998,1010.782,1180.914,960.627,1204.401z\"><\/path><path d=\"M1306.793,621.365V406.939c-1.094-107.793-43.891-208.955-120.511-284.855 C1109.604,46.13,1007.934,4.301,899.996,4.301c-107.933,0-209.604,41.83-286.273,117.788 c-76.617,75.896-119.413,177.057-120.507,285.166v112.333h62.958V407.571c1.898-187.646,156.137-340.313,343.822-340.313 c187.696,0,341.942,152.667,343.839,339.996v214.11H888.52H192.564v474.124c1.906,187.453,76.336,363.382,209.578,495.369 C535.485,1722.948,712.296,1795.7,900.004,1795.7c187.708,0,364.519-72.752,497.863-204.843 c133.242-131.987,207.668-307.916,209.568-495.693V621.365H1306.793z M1544.477,1094.848 c-3.561,351.735-292.671,637.894-644.472,637.894c-351.796,0-640.912-286.158-644.482-637.577v-410.84h237.693h813.578h237.684 V1094.848z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-2a4124bbfa2baebd5e1ea6f52b559ac7\" id=\"externer-not-aus-oder-schlusselschalter\" style=\"font-size:16px\"><strong>External emergency stop or key switch<\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-75ed8c96\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,868.536c-113.664,0-206.139,92.473-206.139,206.145c0,72.752,38.923,140.217,100.683,177.107v167.979 h210.914v-167.979c61.764-36.891,100.689-104.355,100.689-177.107C1106.146,961.009,1013.669,868.536,900,868.536z M960.627,1204.401l-18.129,8.493v143.914h-84.996v-143.914l-18.129-8.493c-50.148-23.487-82.554-74.403-82.554-129.721 c0-78.952,64.232-143.185,143.181-143.185c78.952,0,143.189,64.232,143.189,143.185 C1043.189,1129.998,1010.782,1180.914,960.627,1204.401z\"><\/path><path d=\"M1306.793,621.365V406.939c-1.094-107.793-43.891-208.955-120.511-284.855 C1109.604,46.13,1007.934,4.301,899.996,4.301c-107.933,0-209.604,41.83-286.273,117.788 c-76.617,75.896-119.413,177.057-120.507,285.166v112.333h62.958V407.571c1.898-187.646,156.137-340.313,343.822-340.313 c187.696,0,341.942,152.667,343.839,339.996v214.11H888.52H192.564v474.124c1.906,187.453,76.336,363.382,209.578,495.369 C535.485,1722.948,712.296,1795.7,900.004,1795.7c187.708,0,364.519-72.752,497.863-204.843 c133.242-131.987,207.668-307.916,209.568-495.693V621.365H1306.793z M1544.477,1094.848 c-3.561,351.735-292.671,637.894-644.472,637.894c-351.796,0-640.912-286.158-644.482-637.577v-410.84h237.693h813.578h237.684 V1094.848z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-3966ce745cd1b29c4d0c8d8d5719ac79\" id=\"automatische-abschaltung-bei-netzausfall\" style=\"font-size:16px\"><strong>Automatic shutdown in case of grid failure<\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-788e3825\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,868.536c-113.664,0-206.139,92.473-206.139,206.145c0,72.752,38.923,140.217,100.683,177.107v167.979 h210.914v-167.979c61.764-36.891,100.689-104.355,100.689-177.107C1106.146,961.009,1013.669,868.536,900,868.536z M960.627,1204.401l-18.129,8.493v143.914h-84.996v-143.914l-18.129-8.493c-50.148-23.487-82.554-74.403-82.554-129.721 c0-78.952,64.232-143.185,143.181-143.185c78.952,0,143.189,64.232,143.189,143.185 C1043.189,1129.998,1010.782,1180.914,960.627,1204.401z\"><\/path><path d=\"M1306.793,621.365V406.939c-1.094-107.793-43.891-208.955-120.511-284.855 C1109.604,46.13,1007.934,4.301,899.996,4.301c-107.933,0-209.604,41.83-286.273,117.788 c-76.617,75.896-119.413,177.057-120.507,285.166v112.333h62.958V407.571c1.898-187.646,156.137-340.313,343.822-340.313 c187.696,0,341.942,152.667,343.839,339.996v214.11H888.52H192.564v474.124c1.906,187.453,76.336,363.382,209.578,495.369 C535.485,1722.948,712.296,1795.7,900.004,1795.7c187.708,0,364.519-72.752,497.863-204.843 c133.242-131.987,207.668-307.916,209.568-495.693V621.365H1306.793z M1544.477,1094.848 c-3.561,351.735-292.671,637.894-644.472,637.894c-351.796,0-640.912-286.158-644.482-637.577v-410.84h237.693h813.578h237.684 V1094.848z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-a45300c428dd2c93fcadcc59e26869c3\" id=\"unterspannungserkennung\" style=\"font-size:16px\"><strong>Undervoltage detection<\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-a666f2c1\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,868.536c-113.664,0-206.139,92.473-206.139,206.145c0,72.752,38.923,140.217,100.683,177.107v167.979 h210.914v-167.979c61.764-36.891,100.689-104.355,100.689-177.107C1106.146,961.009,1013.669,868.536,900,868.536z M960.627,1204.401l-18.129,8.493v143.914h-84.996v-143.914l-18.129-8.493c-50.148-23.487-82.554-74.403-82.554-129.721 c0-78.952,64.232-143.185,143.181-143.185c78.952,0,143.189,64.232,143.189,143.185 C1043.189,1129.998,1010.782,1180.914,960.627,1204.401z\"><\/path><path d=\"M1306.793,621.365V406.939c-1.094-107.793-43.891-208.955-120.511-284.855 C1109.604,46.13,1007.934,4.301,899.996,4.301c-107.933,0-209.604,41.83-286.273,117.788 c-76.617,75.896-119.413,177.057-120.507,285.166v112.333h62.958V407.571c1.898-187.646,156.137-340.313,343.822-340.313 c187.696,0,341.942,152.667,343.839,339.996v214.11H888.52H192.564v474.124c1.906,187.453,76.336,363.382,209.578,495.369 C535.485,1722.948,712.296,1795.7,900.004,1795.7c187.708,0,364.519-72.752,497.863-204.843 c133.242-131.987,207.668-307.916,209.568-495.693V621.365H1306.793z M1544.477,1094.848 c-3.561,351.735-292.671,637.894-644.472,637.894c-351.796,0-640.912-286.158-644.482-637.577v-410.84h237.693h813.578h237.684 V1094.848z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-70f2ac7063e5af8311a992cb021f5100\" id=\"kabelbruchuberwachung\" style=\"font-size:16px\"><strong>Cable break monitoring<\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-922c7214\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,868.536c-113.664,0-206.139,92.473-206.139,206.145c0,72.752,38.923,140.217,100.683,177.107v167.979 h210.914v-167.979c61.764-36.891,100.689-104.355,100.689-177.107C1106.146,961.009,1013.669,868.536,900,868.536z M960.627,1204.401l-18.129,8.493v143.914h-84.996v-143.914l-18.129-8.493c-50.148-23.487-82.554-74.403-82.554-129.721 c0-78.952,64.232-143.185,143.181-143.185c78.952,0,143.189,64.232,143.189,143.185 C1043.189,1129.998,1010.782,1180.914,960.627,1204.401z\"><\/path><path d=\"M1306.793,621.365V406.939c-1.094-107.793-43.891-208.955-120.511-284.855 C1109.604,46.13,1007.934,4.301,899.996,4.301c-107.933,0-209.604,41.83-286.273,117.788 c-76.617,75.896-119.413,177.057-120.507,285.166v112.333h62.958V407.571c1.898-187.646,156.137-340.313,343.822-340.313 c187.696,0,341.942,152.667,343.839,339.996v214.11H888.52H192.564v474.124c1.906,187.453,76.336,363.382,209.578,495.369 C535.485,1722.948,712.296,1795.7,900.004,1795.7c187.708,0,364.519-72.752,497.863-204.843 c133.242-131.987,207.668-307.916,209.568-495.693V621.365H1306.793z M1544.477,1094.848 c-3.561,351.735-292.671,637.894-644.472,637.894c-351.796,0-640.912-286.158-644.482-637.577v-410.84h237.693h813.578h237.684 V1094.848z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-8dfb7bc185fb0fd0946fb6231543b617\" id=\"potentialfreie-schnittstellen-fur-brandmeldeanlagen\" style=\"font-size:16px\"><strong>Potential-free interfaces for fire alarm systems<\/strong><\/h3>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-bottom is-layout-flow wp-block-column-is-layout-flow\">\n<h4 id=\"fail-safe-prinzip-fallt-die-versorgungsspannung-aus-oder-wird-die-steuerleitung-unterbrochen-schaltet-q-fire-feuerwehrschalter-pv-automatisch-ab-und-trennt-die-pv-strings-galvanisch-vom-wechselrichter-das-fail-safe-prinzip-erhoht-die-sicherheit-im-brandfall-und-minimiert-das-risiko-ungewollt-spannungsfuhrender-leitungen\" class=\"wp-block-heading dc-card has-neve-text-color-color has-nv-light-bg-background-color has-text-color has-background has-link-color wp-elements-36f82280c4bdeee530b88bd617543465\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-top-style:none;border-top-width:0px;border-right-style:none;border-right-width:0px;border-bottom-style:none;border-bottom-width:0px;border-left-width:1px;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\">Fail-safe principle<br><br><br>If the supply voltage fails or the control cable is interrupted, the QFire PV firefighter switch automatically shuts down and galvanically isolates the PV strings from the inverter.<br><br><br>This fail-safe principle increases safety in the event of fire and minimises the risk of cables remaining unintentionally live.<\/h4>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-3\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);min-height:600px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-454 size-full\" alt=\"Technische Details\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-dark-bg-background-color has-background-dim-90 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-7474c96c491341000bdb4cc87feacf18\" id=\"moglichkeiten-zur-abschaltung-beim-feuerwehrschalter-pv-q-fire\" style=\"font-size:28px\">Emergency Shutdown Options for the QFire PV Firefighter Safety Switch<\/h2>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-6e81cd72 wp-block-columns-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color has-medium-font-size wp-elements-2b42eedd783732cfc51ee4a4db6dc0af\" id=\"q-fire-lite\">QFire LITE<\/h3>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-87b396e5a57b5a57d19b32b8539a489b wp-block-paragraph\" style=\"font-size:16px\"><strong>QFire LITE <\/strong>is a standardised solution for DC-side PV string disconnection in photovoltaic systems. The shutdown is performed via the Switch Box, which is installed close to the PV modules or near the roof entry point.<br>The system is triggered via a simple and clearly defined control interface, for example by an external emergency stop button or control signal.  <\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung-300x300.webp\" alt=\"QFire LITE firefighter safety switch for photovoltaic systems \u2013 standardised and cost-efficient solution\" class=\"wp-image-622\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung.webp 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color has-medium-font-size wp-elements-5128c4ce8fe997aaf1b6436a192e9809\" id=\"q-fire-big\"><strong>QFire BIG<\/strong><\/h3>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-3dfef2c8c9652eeb16894b909ff40ec2 wp-block-paragraph\" style=\"font-size:16px\"><strong>QFire BIG <\/strong>includes a central Control Box with extended functionality for controlling the connected Switch Boxes.<br>The Control Box provides visual status indication and supports integration of external emergency shutdown devices as well as connection to fire alarm systems (FAS) for automatic triggering. <\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch-300x300.webp\" alt=\"Customised QFire BIG firefighter safety switch solution for photovoltaic systems\" class=\"wp-image-621\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch.webp 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<h4 id=\"die-abschaltung-erfolgt-beim-q-fire-lite-durch\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color has-medium-font-size wp-elements-b3f06abe4d9f5853c8ce0965a966a896\"><strong>QFire LITE shutdown can be triggered by:<\/strong><\/h4>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-042b1838\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-3b443179c5deb36e8d1f94242ab27f88 wp-block-paragraph\" style=\"font-size:16px\"><strong>AC-coupled shutdown via the grid supply in case of power failure \u2013 <strong>automatic restart <\/strong>when the grid returns<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-af8bde3a\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-2b70046837e81bb447a03dc264ff54bc wp-block-paragraph\" style=\"font-size:16px\"><strong>External emergency stop<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-36e4fbd4\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-ca23832a212a7db65663b22ec75da4a9 wp-block-paragraph\" style=\"font-size:16px\"><strong>triggered by undervoltage caused by a cable break or by significant fluctuations in the AC grid<\/strong><\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<h4 id=\"die-abschaltung-erfolgt-beim-q-fire-big-durch\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color has-medium-font-size wp-elements-de20fcbd3d20cdbce013f28cc546ae27\"><strong>QFire BIG shutdown can be triggered by:<\/strong><\/h4>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-4d92594c\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-3b443179c5deb36e8d1f94242ab27f88 wp-block-paragraph\" style=\"font-size:16px\"><strong>AC-coupled shutdown via the grid supply in case of power failure \u2013 <strong>automatic restart <\/strong>when the grid returns<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-a8c9bcd7\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-2b70046837e81bb447a03dc264ff54bc wp-block-paragraph\" style=\"font-size:16px\"><strong>External emergency stop<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-8fb24df3\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-7ccfd4fae6f1d54b568f4b07352b2f23 wp-block-paragraph\" style=\"font-size:16px\"><strong>Undervoltage caused by cable breakage or strong AC grid fluctuations<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-360b5c80\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-cf48b0164c37679d78225dd35ff5b5c2 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Manual shutdown via the Control Box <\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-bebc429c\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-f5b55e8d66e3f27c1d0163749212142c wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Connection to a fire alarm control panel<\/strong><\/strong><\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-buttons is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-fe48e5de wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-75 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-lite-firefighter-switch\/\" style=\"border-width:1px\">Discover QFire LITE \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-buttons is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-fe48e5de wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-75 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\" style=\"border-width:1px\">Discover QFire BIG \u2192<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-group alignwide\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-fc17ce306312e7f2120f8cc9f6f5e7c6\" id=\"passende-externe-schalter-fur-den-feuerwehrschalter-pv-not-aus-schlusselschalter-not-aus-hinter-glas\">Suitable external switches for PV firefighter safety switches (emergency stop, key switch, break-glass emergency stop)<\/h3>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-0b2fb921 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--80);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--80)\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:33%\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-thumbnail\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_400px-150x150.webp\" alt=\"External emergency stop button for the QFire PV firefighter safety switch\" class=\"wp-image-1574\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_400px-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_400px.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50)\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-thumbnail\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Schluesselschalter_Aufputz_400px-150x150.webp\" alt=\"External key switch for the QFire PV firefighter safety switch\" class=\"wp-image-1578\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Schluesselschalter_Aufputz_400px-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Schluesselschalter_Aufputz_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Schluesselschalter_Aufputz_400px.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50)\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-thumbnail\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_hinter-Glas_400px-150x150.webp\" alt=\"Break-glass emergency stop for the QFire PV firefighter safety switch\" class=\"wp-image-1576\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_hinter-Glas_400px-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_hinter-Glas_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_hinter-Glas_400px.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n<\/div><\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-454 size-full\" alt=\"\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-site-bg-background-color has-background-dim-90 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-acda9440ec252f8e2fab1f4a175a8472\" id=\"steuerbox-schaltbox\">QFire BIG Control Unit \u2013 Central Control of the Firefighter Safety Switch System<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide are-vertically-aligned-center has-neve-link-color-color has-text-color has-link-color wp-elements-110cb207e4dd991109386a575476fdb9 is-layout-flex wp-container-core-columns-is-layout-34acad51 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<figure class=\"wp-block-image size-full has-custom-border q3-duotone wp-duotone-unset-4\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Steuerbox-zentrale-Logik-des-Feuerwehrschalter-Systems.webp\" alt=\"QFire Control Box \u2013 Central Logic and Control of the Firefighter Safety Switch System\" class=\"wp-image-804\" style=\"border-radius:16px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Steuerbox-zentrale-Logik-des-Feuerwehrschalter-Systems.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Steuerbox-zentrale-Logik-des-Feuerwehrschalter-Systems-300x225.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Steuerbox-zentrale-Logik-des-Feuerwehrschalter-Systems-768x576.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30);flex-basis:50%\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-9aff3928\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-064dbb82acda6b3b52936bd855fcfd12 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Monitoring of control signals<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-86f1063a\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-cf13b8694092762298621fb8ea452bf7 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Status indicator<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-afe95eab\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-04cbea2c5168d1ba910b47b68d0da7a9 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Control of individual or multiple Switch Boxes<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-19b66dc8\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-5906be52f5dbe9924ec361aba80f76af wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Triggering via defined control interfaces<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-69678621\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-c5ca05a3fa834c51c474c3877b71579e wp-block-paragraph\" style=\"font-size:16px\"><strong><strong>Potential-free interfaces for fire alarm systems (FAS\/FACP)<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-51b207f6da57172dcd9f62d3692c4ee5 wp-block-paragraph\" style=\"font-size:16px\">The Control Box is the central control element of the QFire PV firefighter safety switch system. It processes incoming control signals and transmits the shutdown commands to the connected Switch Boxes in the event of activation. <br><br>Triggering is performed via a clearly defined control interface, for example through an external firefighter emergency button, a fire alarm system or an AC-coupled shutdown in case of grid failure.<\/p>\n\n\n\n<h4 id=\"die-dc-seitige-abschaltung-erfolgt-ausschliesslich-in-den-schaltboxen-die-steuerbox-ubernimmt-lediglich-die-sichere-ansteuerung-und-uberwachung-des-systems\" class=\"wp-block-heading dc-card has-neve-text-color-color has-nv-light-bg-background-color has-text-color has-background has-link-color wp-elements-d6699397e043f2df0ebf2ebb051bb546\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-top-style:none;border-top-width:0px;border-right-style:none;border-right-width:0px;border-bottom-style:none;border-bottom-width:0px;border-left-width:1px;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\">The DC-side shutdown itself is performed exclusively inside the Switch Boxes. The Control Box is responsible only for safe system control and monitoring.<\/h4>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-group alignwide is-vertical is-layout-flex wp-container-core-group-is-layout-cdcf19ed wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--70);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--70);padding-left:var(--wp--preset--spacing--50)\"><\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\"><img loading=\"lazy\" decoding=\"async\" width=\"1058\" height=\"800\" class=\"wp-block-cover__image-background wp-image-812 size-full\" alt=\"Cluster Steuerbox f\u00fcr mehrere Generatorfl\u00e4chen\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp 1058w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-300x227.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-1024x774.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-768x581.webp 768w\" sizes=\"auto, (max-width: 1058px) 100vw, 1058px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center has-nv-site-bg-color has-text-color has-link-color wp-elements-d7ee362835884bbb964d0e8f6b68e305 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--20);padding-right:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--20);padding-left:var(--wp--preset--spacing--20);flex-basis:50%\">\n<h2 id=\"cluster-steuerbox-fur-mehrere-dachflachen-und-generatorfelder\" class=\"wp-block-heading has-nv-text-dark-bg-color has-text-color\">Cluster Control Box for Multiple Roof Areas and Generator Fields<\/h2>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-6515a2a7234127755ba56d65d6696adb is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-cf79ac06\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-5351dea551e677193920fcf428422211 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong>Star-shaped connection of multiple Switch Boxes<\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-7b72706549260d8bcd98196ecac84a7a is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-d6389cee\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-9f947eeac1fd44b9b8d5b8fdbf373a91 wp-block-paragraph\" style=\"font-size:16px\"><strong>Simultaneous shutdown of multiple roof areas or generator fields<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-150d023e339f0d0010f2dc607eee0e90 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-bc617975\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-50f8b2dc15e78c0f5149e56f4ff0ef31 wp-block-paragraph\" style=\"font-size:16px\"><strong>Suitable for large and complex rooftop systems and ground-mounted PV systems<\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">For larger photovoltaic systems with multiple roof areas or generator fields, the QFire Cluster Control Box is used. It enables central control of several Switch Boxes installed in different locations. <br><br>The Switch Boxes are connected to the Cluster Control Box in a star-shaped configuration. This allows multiple roof areas or generator sections to be shut down centrally and simultaneously. <\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--20);padding-left:var(--wp--preset--spacing--20);flex-basis:50%\"><div class=\"wp-block-image q3-duotone wp-duotone-unset-5\">\n<figure class=\"aligncenter size-full has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Beispiel-Feuerwehrschalter-mehrere-Dachflaechen-mit-QFire-Cluster-System.webp\" alt=\"Example of a QFire cluster system for multiple roof areas and generator fields\" class=\"wp-image-815\" style=\"border-radius:16px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Beispiel-Feuerwehrschalter-mehrere-Dachflaechen-mit-QFire-Cluster-System.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Beispiel-Feuerwehrschalter-mehrere-Dachflaechen-mit-QFire-Cluster-System-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Beispiel-Feuerwehrschalter-mehrere-Dachflaechen-mit-QFire-Cluster-System-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Beispiel-Feuerwehrschalter-mehrere-Dachflaechen-mit-QFire-Cluster-System-768x768.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-bd32d676880eb2ec4bcc7e77a3d7e5c7 wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-color:var(--wp--preset--color--nv-c-2);border-left-color:var(--wp--preset--color--nv-text-dark-bg);background-color:#ffffff08;font-size:16px\">Using cluster technology, complete PV system sections or multiple roof areas can be shut down simultaneously. This is particularly advantageous for <strong>commercial, industrial and large-scale solar installations<\/strong> with several generator sections or feed-in points. The cluster architecture also allows flexible expansion for large and complex photovoltaic system structures.  <\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"q-fire-cluster-system-koordinierte-dc-abschaltung-mehrerer-generatorfelder\" class=\"wp-block-heading\">QFire cluster system: coordinated DC shutdown of multiple generator fields<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Example: five generator fields, each with its own Cluster Control Box, with common triggering via one central external emergency stop<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"591\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/QFire-Cluster-System-DC-Abschaltung-fuer-mehrere-Generatorfelder-1024x591.webp\" alt=\"QFire cluster system with five generator fields, one QFire Cluster Control Box per generator field, star-shaped connection of five clusters per field and one central external emergency stop for common triggering via the interconnected Cluster Control Boxes.&lt;br\/&gt;A central external emergency stop \/ key switch triggers the connected Cluster Control Boxes together. DC disconnection is carried out within the respective generator fields.  \" class=\"wp-image-9245\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/QFire-Cluster-System-DC-Abschaltung-fuer-mehrere-Generatorfelder-1024x591.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/QFire-Cluster-System-DC-Abschaltung-fuer-mehrere-Generatorfelder-300x173.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/QFire-Cluster-System-DC-Abschaltung-fuer-mehrere-Generatorfelder-768x444.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/QFire-Cluster-System-DC-Abschaltung-fuer-mehrere-Generatorfelder-1536x887.webp 1536w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/QFire-Cluster-System-DC-Abschaltung-fuer-mehrere-Generatorfelder.webp 1600w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column dc-card has-nv-light-bg-background-color has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"border-style:none;border-width:0px;border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40)\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-1405c5ce\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M1506.693,279.092h-150.36v-85.277c0-17.353-14.065-31.418-31.419-31.418h-227.317 C1078.205,70.574,996.5,2.304,900.003,2.304c-96.499,0-178.202,68.27-197.595,160.092H475.091 c-17.353,0-31.419,14.065-31.419,31.418v85.277H293.307c-17.353,0-31.419,14.066-31.419,31.419v1455.764 c0,17.353,14.066,31.419,31.419,31.419h1213.386c17.354,0,31.42-14.066,31.42-31.419V310.511 C1538.113,293.158,1524.047,279.092,1506.693,279.092z M506.511,225.234h223.28c16.617,0,30.354-12.935,31.362-29.517 c4.436-73.219,65.424-130.574,138.85-130.574c73.425,0,134.413,57.355,138.849,130.574c1.009,16.582,14.746,29.517,31.363,29.517 h223.28v53.858v62.838v74.81H506.511v-74.81v-62.838V225.234z M1475.274,1734.855H324.728V341.93h118.944v106.229 c0,17.354,14.066,31.419,31.419,31.419h849.823c17.354,0,31.419-14.066,31.419-31.419V341.93h118.941V1734.855z\"><\/path><path d=\"M663.633,684.019L534.366,813.291l-57.803-57.806c-12.272-12.265-32.164-12.265-44.437,0 c-12.269,12.272-12.269,32.164,0,44.437l80.021,80.022c6.136,6.132,14.176,9.201,22.219,9.201c8.043,0,16.083-3.069,22.219-9.201 l151.486-151.486c12.269-12.273,12.269-32.165,0-44.438C695.799,671.755,675.907,671.755,663.633,684.019z\"><\/path><path d=\"M824.996,750.563c-17.354,0-31.419,14.066-31.419,31.419c0,17.354,14.066,31.419,31.419,31.419h520.665 c17.354,0,31.419-14.066,31.419-31.419c0-17.353-14.065-31.419-31.419-31.419H824.996z\"><\/path><path d=\"M663.633,1039.925l-129.267,129.272l-57.803-57.807c-12.272-12.265-32.164-12.265-44.437,0 c-12.269,12.272-12.269,32.164,0,44.438l80.021,80.021c6.136,6.133,14.176,9.2,22.219,9.2c8.043,0,16.083-3.067,22.219-9.2 l151.486-151.486c12.269-12.272,12.269-32.163,0-44.438C695.799,1027.66,675.907,1027.66,663.633,1039.925z\"><\/path><path d=\"M1345.661,1106.467H824.996c-17.354,0-31.419,14.066-31.419,31.42s14.066,31.42,31.419,31.42h520.665 c17.354,0,31.419-14.066,31.419-31.42S1363.015,1106.467,1345.661,1106.467z\"><\/path><path d=\"M663.633,1395.83l-129.267,129.272l-57.803-57.808c-12.272-12.264-32.164-12.264-44.437,0 c-12.269,12.274-12.269,32.166,0,44.439l80.021,80.021c6.136,6.132,14.176,9.199,22.219,9.199c8.043,0,16.083-3.067,22.219-9.199 l151.486-151.486c12.269-12.274,12.269-32.166,0-44.438C695.799,1383.566,675.907,1383.566,663.633,1395.83z\"><\/path><path d=\"M1345.661,1462.373H824.996c-17.354,0-31.419,14.066-31.419,31.42s14.066,31.418,31.419,31.418h520.665 c17.354,0,31.419-14.064,31.419-31.418S1363.015,1462.373,1345.661,1462.373z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">Each generator field has its own QFire Cluster Control Box. Each Cluster Control Box connects five clusters within the field in a star-shaped configuration. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">All five Cluster Control Boxes are interconnected and can be triggered together via one central external emergency stop.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column dc-card has-nv-light-bg-background-color has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"border-style:none;border-width:0px;border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-top:var(--wp--preset--spacing--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40)\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-2a1f38f4\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M246.051,1796.104c-2.663,0-5.348-0.336-7.992-1.025l-166.817-43.505 c-11.095-2.895-19.762-11.557-22.656-22.654L5.044,1562.08c-2.839-10.881,0.3-22.446,8.251-30.397l101.307-101.312 c0.476-0.544,0.968-1.069,1.481-1.587l668.3-668.298c-43.625-93.255-59.486-199.569-44.681-301.964 c16.48-114,68.356-217.425,150.023-299.096C990.027,59.131,1123.381,3.896,1265.223,3.896 c141.839,0,275.184,55.23,375.479,155.521c207.043,207.047,207.043,543.934,0,750.977 c-100.277,100.277-233.622,155.512-375.456,155.517c-77.911,0.005-155.419-17.284-225.608-50.161l-198.6,198.589 c-5.219,5.22-12.101,8.454-19.45,9.14l-96.017,8.972l-8.967,96.021c-0.686,7.35-3.92,14.23-9.14,19.454l-0.805,0.805 c-5.224,5.219-12.104,8.454-19.454,9.14l-96.02,8.967l-8.965,96.018c-0.689,7.371-3.938,14.27-9.184,19.498l-1.237,1.233 c-5.215,5.197-12.081,8.414-19.413,9.1l-95.584,8.927l-8.925,95.58c-0.688,7.354-3.92,14.235-9.144,19.459l-67.392,67.384 c-0.521,0.521-1.057,1.021-1.604,1.498l-101.283,101.289C262.438,1792.842,254.346,1796.104,246.051,1796.104z M105.198,1694.951 l131.287,34.242l90.004-90.012c0.518-0.517,1.05-1.017,1.598-1.494l57.77-57.762l10.304-110.354 c1.417-15.167,13.429-27.18,28.596-28.598l96.718-9.034l9.069-97.144c1.416-15.168,13.429-27.18,28.596-28.599l96.753-9.038 l9.038-96.755c1.419-15.163,13.427-27.176,28.594-28.594l110.792-10.351l206.612-206.602c9.797-9.802,24.846-12.091,37.114-5.652 c66.53,34.905,141.635,53.353,217.198,53.348c124.917-0.005,242.346-48.646,330.656-136.959 c182.347-182.343,182.347-479.03,0-661.377c-88.318-88.323-205.758-136.964-330.674-136.964 c-124.92,0-242.363,48.645-330.699,136.977C788.967,349.79,755.365,569.959,850.918,752.09 c6.444,12.277,4.154,27.312-5.648,37.119l-682.855,682.847c-0.473,0.543-0.966,1.073-1.479,1.586l-90.005,90.003L105.198,1694.951 z\"><\/path><path d=\"M1273.541,713.839c-48.809,0-94.691-19.008-129.203-53.524c-71.242-71.242-71.246-187.168-0.01-258.411 c34.512-34.512,80.395-53.52,129.203-53.52s94.701,19.008,129.217,53.52c34.516,34.516,53.523,80.403,53.523,129.208 c0,48.809-19.008,94.696-53.523,129.208C1368.236,694.831,1322.35,713.839,1273.541,713.839z M1273.531,411.742 c-31.881,0-61.854,12.414-84.398,34.958c-46.541,46.541-46.537,122.273,0.01,168.814c22.543,22.548,52.516,34.967,84.398,34.967 c31.887,0,61.863-12.418,84.407-34.967c22.548-22.543,34.966-52.517,34.966-84.403c0-31.882-12.418-61.859-34.966-84.403 C1335.4,424.161,1305.418,411.742,1273.531,411.742z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"wp-block-paragraph\">A central external emergency stop \/ key switch can trigger all connected Cluster Control Boxes together. DC disconnection is then carried out within the respective generator fields. <\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\" style=\"padding-top:var(--wp--preset--spacing--70);padding-bottom:var(--wp--preset--spacing--70)\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-454 size-full\" alt=\"\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-site-bg-background-color has-background-dim-90 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<h2 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-eb4a5dfd310c3a97b9e6a5af40f720c9\" id=\"die-schaltbox-dc-seitige-stringabschaltung\">The Switching Unit \u2013 DC-Side PV String Disconnection<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-a024a45d4590b480069ded0cbbc99de6 is-layout-flex wp-container-core-columns-is-layout-34acad51 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\"><div class=\"wp-block-image is-style-default wp-duotone-unset-6\">\n<figure class=\"aligncenter size-full has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"901\" height=\"600\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Schaltbox.webp\" alt=\"Technical diagram of the QFire Switch Box for PV firefighter safety shutdown\" class=\"wp-image-828\" style=\"border-radius:16px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Schaltbox.webp 901w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Schaltbox-300x200.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Schaltbox-768x511.webp 768w\" sizes=\"auto, (max-width: 901px) 100vw, 901px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30);flex-basis:50%\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-6044d06a\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-4c9a78549ece83be894630dd0c519869 wp-block-paragraph\" style=\"font-size:16px\"><strong>Two-pole galvanic isolation<\/strong> of the positive and negative conductors of each PV string<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-6e3d9e29\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-bd4df8e66d2860d7ab408ce9c7e39017 wp-block-paragraph\" style=\"font-size:16px\">Designed for PV systems <strong>up to 1,500 V DC and 20 A per string<\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-538867a3\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.996,6.911C405.643,6.911,3.458,409.103,3.458,903.462C3.458,1397.811,405.643,1800,899.996,1800 c494.357,0,896.546-402.189,896.546-896.538C1796.542,409.103,1394.353,6.911,899.996,6.911z M899.996,1737.1 c-459.667,0-833.637-373.97-833.637-833.638c0-459.679,373.969-833.649,833.637-833.649c459.672,0,833.644,373.971,833.644,833.649 C1733.64,1363.13,1359.668,1737.1,899.996,1737.1z\"><\/path><path d=\"M1073.088,393.764v66.982c176.77,69.347,302.257,241.646,302.257,442.716 c0,262.101-213.239,475.332-475.349,475.332c-262.101,0-475.336-213.231-475.336-475.332 c0-201.075,125.491-373.374,302.261-442.725v-66.973c-212.139,72.23-365.162,273.421-365.162,509.698 c0,296.781,241.452,538.234,538.238,538.234c296.79,0,538.251-241.453,538.251-538.234 C1438.247,667.194,1285.223,466.002,1073.088,393.764z\"><\/path><path d=\"M900.004,880.287c17.371,0,31.45-14.084,31.45-31.451V286.086c0-17.371-14.079-31.451-31.45-31.451 c-17.37,0-31.45,14.08-31.45,31.451v562.749C868.554,866.202,882.634,880.287,900.004,880.287z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-56f4c88caaec9e7c3cdc71227186cd6f wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong>Optional integrated surge protection and\/or integrated fuses in the positive and negative poles<\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-03386337803a0aaf351611a026cbc698 wp-block-paragraph\" style=\"font-size:16px\">Depending on the configuration, multiple PV strings can be integrated into a single Switch Box. Optional surge protection modules can also be included to provide additional protection against transient overvoltages. <\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h4 id=\"die-schaltbox-ubernimmt-die-eigentliche-dc-seitige-abschaltung-der-pv-strings-jeder-string-wird-zweipolig-galvanisch-getrennt-sodass-im-auslosefall-keine-gefahrliche-dc-spannung-mehr-am-ausgang-der-schaltbox-anliegt\" class=\"wp-block-heading dc-card has-neve-text-color-color has-nv-light-bg-background-color has-text-color has-background has-link-color wp-elements-0d2c78e8e6f57bef6e011e5bd94cca09\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-top-style:none;border-top-width:0px;border-right-style:none;border-right-width:0px;border-bottom-style:none;border-bottom-width:0px;border-left-width:1px;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\">The Switch Box performs the actual DC-side shutdown of the PV strings. Each string is galvanically isolated on both poles so that no dangerous DC voltage remains at the output of the Switch Box after activation. <\/h4>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"427\" class=\"wp-block-cover__image-background wp-image-454 size-large\" alt=\"Technische Details\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1536x640.webp 1536w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-container-core-cover-is-layout-a48333fe wp-block-cover-is-layout-constrained\">\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-5b0bc1de wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<div class=\"wp-block-column is-vertically-aligned-bottom is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<h2 id=\"normen\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-544de0f6eb2889e7985082e700547881\" style=\"font-size:28px\">Standards and Regulations for PV Firefighter Safety Switches<\/h2>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-6c7ad8325449d1e8aa77319d22a77eeb wp-block-paragraph\" style=\"font-size:16px\">The requirements for shutdown devices in photovoltaic systems are based on various standards and technical regulations. Important references include:  <\/p>\n\n\n\n<h3 id=\"\u25a0-din-vde-0105-100-betrieb-elektrischer-anlagen\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-00d90307dadb56df48931fa7b03269b7\" style=\"font-size:20px\"><strong>\u25a0<\/strong> DIN VDE 0105-100 \u2013 Operation of electrical installations<\/h3>\n\n\n\n<h3 id=\"\u25a0-vde-ar-e-2100-712-brandschutz-bei-pv-anlagen\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-2bc4d00307bc5ba6982334079931d85b\" style=\"font-size:20px\"><strong>\u25a0<\/strong> VDE-AR-E 2100-712 \u2013 Fire safety for photovoltaic systems<\/h3>\n\n\n\n<h3 id=\"\u25a0-iec-60947-3-schalter-und-lasttrennschalter-fur-niederspannung\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-35b3c5fdc143a848b5404d0fbb1a67a4\" style=\"font-size:20px\"><strong>\u25a0<\/strong> IEC 60947-3 \u2013 Switches, disconnectors and switch-disconnectors for low-voltage applications<\/h3>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-639cc858b7d776162ffe30f71d8c4d64 wp-block-paragraph\" style=\"font-size:16px\"><br>PV firefighter safety switches must reliably provide galvanic isolation of the photovoltaic system so that no dangerous voltage remains on the cables after shutdown.<br><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-bottom has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-1bbb776c88b10998fa0dba884f2d496e is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<h4 id=\"normative-grundlagen-technische-hinweise-ergeben-sich-u-a-aus-dem-vde-regelwerk-z-b-din-vde-0100-712-vde-ar-e-2100-712-sowie-aus-handlungsempfehlungen-der-feuerwehren-zum-einsatz-an-pv-anlagen-fur-die-ausfuhrung-der-schaltgerate-selbst-sind-zudem-die-anforderungen-der-iec-60947-3-massgeblich-die-die-sichere-trenn-und-schaltfunktion-von-lasttrennschaltern-definiert\" class=\"wp-block-heading dc-card has-neve-text-color-color has-nv-light-bg-background-color has-text-color has-background has-link-color wp-elements-ea259c2d3354ec92f1234bec038fb566\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-top-style:none;border-top-width:0px;border-right-style:none;border-right-width:0px;border-bottom-style:none;border-bottom-width:0px;border-left-width:1px;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\">Normative Framework<br><br>Technical guidance is based, among other things, on VDE regulations such as DIN VDE 0100-712 and VDE-AR-E 2100-712, as well as recommendations issued by fire services for operations involving photovoltaic systems.<br>For the switching devices themselves, the requirements of IEC 60947-3 are particularly relevant, as this standard defines the safe switching and isolation functions of switch-disconnectors. <\/h4>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color has-border-color has-neve-text-color-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/wissen\/pflicht\/\" style=\"border-width:1px\">Are PV Firefighter Safety Switches Mandatory? \u2192<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns are-vertically-aligned-center is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:75%\">\n<h2 id=\"was-ist-bei-der-planung-eines-pv-feuerwehrschalters-wichtig\" class=\"wp-block-heading\">What is important when planning a PV firefighter switch?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">When planning a firefighter switch for PV systems, the number of strings is not the only decisive factor. Cable routes, roof entry points, inverter structure, MPPT allocation, surge protection, possible fire alarm systems, external emergency stop points and the question of whether several roof areas or generator fields need to be shut down together are also important. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For smaller systems, a standardised solution such as QFire LITE may be sufficient. For larger commercial systems, public buildings, multiple roof areas or complex shutdown concepts, project-specific planning with QFire BIG is usually the better choice. <\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-primary\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/pv-firefighter-switches-planning\/\" style=\"border-width:1px\">Plan PV firefighter switch online \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:25%\">\n<figure class=\"wp-block-image size-full q3-duotone\"><a href=\"https:\/\/q3-energie.de\/en\/pv-firefighter-switches-planning\/\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"600\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Q3-KI-SQAY-hilft-Feuerwehrschalter-zu-planen.webp\" alt=\"Q3 AI SQAY helps with planning PV firefighter switches\" class=\"wp-image-8639\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Q3-KI-SQAY-hilft-Feuerwehrschalter-zu-planen.webp 600w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Q3-KI-SQAY-hilft-Feuerwehrschalter-zu-planen-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Q3-KI-SQAY-hilft-Feuerwehrschalter-zu-planen-150x150.webp 150w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"600\" class=\"wp-block-cover__image-background wp-image-3815 size-full\" alt=\"QFire Feuerwehrschalter Technik Referenz\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz-300x225.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/04\/QFire-Feuerwehrschalter-Technik-Referenz-768x576.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-d4ef8ce39430dc5275d1e8411324ab12 is-layout-flex wp-container-core-columns-is-layout-34acad51 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-top has-nv-site-bg-color has-text-color has-link-color wp-elements-3ef196a3e9537f8058bc16b131dae13d is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:75%\">\n<h2 id=\"haufige-fragen-zu-feuerwehrschaltern-fur-pv-anlagen\" class=\"wp-block-heading\">Frequently Asked Questions About PV Firefighter Safety Switches<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div id=\"wp-block-themeisle-blocks-accordion-1e20aca1\" class=\"wp-block-themeisle-blocks-accordion icon-first has-icon has-open-icon is-style-default has-light-content-bg\">\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>Is a PV firefighter safety switch mandatory?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">There is no universal legal requirement for PV firefighter safety switches.<br>Whether a firefighter safety switch is required depends on local building regulations, the fire protection concept, project-specific requirements and the specifications of the fire service, insurer or system operator.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-75\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/wissen\/pflicht\/\">Learn More: Are PV Firefighter Safety Switches Mandatory? \u2192<\/a><\/div>\n<\/div>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>How does a PV firefighter safety switch work?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">A firefighter safety switch disconnects the PV strings on the DC side from the inverter.<br>As a result, the cables between the Switch Box and the inverter become de-energised, while the PV modules themselves may continue to generate voltage when exposed to light.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-75\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/technic\/pv-firefighter-safety-switch\/\">Learn More About How the QFire Firefighter Safety Switch Works \u2192<\/a><\/div>\n<\/div>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>How does DC-side shutdown work in PV systems?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">DC-side shutdown disconnects the connection between the PV generator and the inverter on the DC side. With QFire, this is carried out via Switch Boxes installed close to the PV generator, for example at the roof entry point or near the PV string routing. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">Depending on the system concept, triggering can be automatic or manual, for example via grid monitoring, a firefighter emergency stop, a key switch, a Control Box or a signal from the fire alarm control panel. In the event of shutdown, the Switch Boxes galvanically isolate the connected PV strings. As a result, the cables from the shutdown point towards the inverter are de-energised.  <\/p>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>What does galvanic isolation according to IEC 60947-3 mean?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">Galvanic isolation means that the electrical connection is not only switched electronically, but physically disconnected. In PV systems, this is particularly important because high DC voltages can occur and DC arcs are technically more demanding to control than AC arcs. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">IEC 60947-3 defines requirements for switches, disconnectors and switch-disconnectors. For firefighter switches, this means that the shutdown function must provide a suitable isolation function and reliably disconnect the PV strings from the downstream part of the system.  <\/p>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>Where is a PV firefighter safety switch installed?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">A firefighter switch is installed where the DC cables can be disconnected in a technically meaningful and clearly defined way. In practice, this is often close to the PV generator, near the roof entry point, on the fa\u00e7ade, in the technical area or at a defined transition point between the PV generator and the inverter. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">The decisive factor is not only the installation location of the device, but the effect of the shutdown. The cables from the disconnection point towards the inverter should become de-energised. The installation location must therefore match the cable routing, fire protection concept and system structure. <\/p>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>What is the difference between string-level and module-level shutdown?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">With string-level shutdown, multiple PV modules are disconnected together as one string, whereas module-level shutdown disconnects each individual module separately.<br>String-level shutdown is considered a technically robust and economically efficient solution, particularly for larger commercial and industrial photovoltaic systems.<\/p>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>How many strings and MPPTs can a QFire Switch Box handle?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">A QFire Switch Box can support up to 12 MPPTs and up to 24 strings per system.<br>By using additional Switch Boxes, the system can be expanded modularly. The architecture is scalable and can be adapted for larger photovoltaic installations.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-75\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\">Learn More About QFire BIG \u2192<\/a><\/div>\n<\/div>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>Can a PV firefighter safety switch be connected to a fire alarm system?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">Yes. Depending on the system concept, a firefighter switch can be integrated into a higher-level shutdown or fire protection concept. With QFire, triggering is possible via external signals, for example via an emergency stop, key switch or connection to a fire alarm control panel. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">The interface to the fire alarm system must be planned properly and coordinated with the fire protection concept, electrical planning and site-specific requirements. <\/p>\n<\/div><\/details>\n\n\n\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>Can QFire BIG also provide an AC-side shutdown signal?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">QFire BIG is primarily a system for DC-side PV generator disconnection. However, via suitable interfaces and status contacts, the system can be integrated into a higher-level shutdown concept and provide signals for external components. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">Depending on the project design, QFire BIG can therefore be part of a coordinated DC\/AC shutdown concept. The actual AC-side switching is performed by suitable external AC components, such as contactors, switch-disconnectors or AC connection boxes.  <\/p>\n<\/div><\/details>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-buttons alignwide is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-75 is-style-secondary dc-card\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/faq-pv-firefighter-switch\/\" style=\"border-width:1px\">Here you will find an overview of all frequently asked questions about PV firefighter safety switches \u2192<\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-7\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);min-height:600px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-465 size-full\" alt=\"\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-80 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-fa8a20298efd6a7c069beab2982f3095\" id=\"plug-play-installation-q-fire-feuerwehrschalter-pv\">Plug &amp; Play Installation of the QFire PV Firefighter Safety Switch<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-dc9fa487 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30)\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:33%\">\n<figure class=\"wp-block-image size-full is-style-default\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"555\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-Uebersicht-Gegenstecker.webp\" alt=\"Easy installation: no internal wiring of the control cables to terminal blocks required\" class=\"wp-image-843\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-Uebersicht-Gegenstecker.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-Uebersicht-Gegenstecker-300x208.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-Uebersicht-Gegenstecker-768x533.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:67%\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-ef8e62ad534e3282568d0bfe76868ce2 is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-a4aaae0d\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-501629524a94f7952940e10e5214e771 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong><strong>Easy installation: no internal wiring of the control cables to terminal blocks required<\/strong><\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-105dae4b\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-f1791ab3434f7ce7accf0623d9168071 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong><strong>Reduced installation effort: matching plug connectors supplied<\/strong><\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-ad694a66 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40)\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-8775b981\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-e7b9e2ba5a598f712d9f47e3a7e99939 wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong><strong>Reduced risk of installation errors through clearly defined plug connections instead of individual terminal wiring<\/strong><\/strong><\/strong><\/strong><\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card is-nowrap is-layout-flex wp-container-core-group-is-layout-d05033d9 wp-block-group-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:0;padding-bottom:var(--wp--preset--spacing--40);padding-left:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-43da8cff\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M900,1793.016c-2.796,0-5.594-0.375-8.315-1.125c-7.969-2.199-197.36-55.807-388.728-226.607 c-112.377-100.305-201.914-220.375-266.128-356.88c-79.987-170.042-120.543-365.937-120.543-582.248 c0-9.624,4.431-18.711,12.016-24.637L880.752,13.613c11.308-8.837,27.187-8.837,38.496,0l752.451,587.905 c7.584,5.925,12.016,15.013,12.016,24.637c0,216.312-40.559,412.206-120.546,582.248 c-64.212,136.505-153.751,256.575-266.123,356.88c-191.37,170.801-380.764,224.408-388.732,226.607 C905.592,1792.641,902.796,1793.016,900,1793.016z M178.88,641.351c3.271,367.343,125.555,661.791,363.594,875.387 C701.154,1659.123,862.076,1716.81,900,1729.049c37.924-12.239,198.846-69.926,357.525-212.311 c238.039-213.597,360.325-508.044,363.592-875.387L900,77.925L178.88,641.351z\"><\/path><path d=\"M900,1593.533c-2.798,0-5.594-0.375-8.315-1.125c-6.189-1.71-153.319-43.35-301.636-175.734 c-87.095-77.732-156.485-170.791-206.251-276.582c-61.928-131.65-93.328-283.236-93.328-450.545 c0-9.624,4.432-18.711,12.017-24.637L880.752,213.1c11.308-8.834,27.187-8.839,38.496,0l578.266,451.81 c7.585,5.925,12.017,15.013,12.017,24.637c0,167.309-31.399,318.895-93.329,450.545 c-49.762,105.791-119.155,198.85-206.248,276.582c-148.316,132.385-295.446,174.024-301.64,175.734 C905.596,1593.158,902.798,1593.533,900,1593.533z M353.087,704.725c3.256,278.249,96.237,501.402,276.493,663.417 c118.248,106.279,238.227,150.755,270.42,161.38c32.193-10.625,152.172-55.101,270.42-161.38 c180.256-162.016,273.236-385.169,276.495-663.417L900,277.412L353.087,704.725z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-bc71f6afd69a4700e7e5a0dc44cd765e wp-block-paragraph\" style=\"font-size:16px\"><strong><strong><strong><strong>Project-specific configuration: connections adapted to the individual system layout<\/strong><\/strong><\/strong><\/strong><\/p>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h4 id=\"die-q-fire-systeme-sind-mit-einer-plug-play-losung-ausgestattet-um-die-installation-des-feuerwehrschalters-deutlich-zu-vereinfachen-und-zu-beschleunigen-kern-dieser-losung-sind-kundenspezifisch-vorverdrahtete-anschlusse-an-der-steuerbox-sowie-an-den-schaltboxen\" class=\"wp-block-heading dc-card has-neve-text-color-color has-text-color has-background has-link-color wp-elements-ee11a7c3ea3ed28d8f0aa5032889768b\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-style:none;border-right-width:0px;border-left-color:var(--wp--preset--color--neve-text-color);border-left-width:1px;background-color:#f5f6f79e;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);font-size:16px\">QFire systems are equipped with a plug-and-play connection concept designed to simplify and accelerate installation of the PV firefighter safety switch system. A key feature of this solution is the use of project-specific pre-wired connectors on both the Control Box and the Switch Boxes. <\/h4>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-b6217b4173e4931ea6e06d9a842df6f4 wp-block-paragraph\">This connector-based installation concept significantly simplifies on-site assembly. Only the grid connection and grounding still require internal wiring. As a result, installation times are reduced, wiring errors are minimised and installation reliability is increased \u2014 especially in larger photovoltaic systems with multiple Switch Boxes.<br>.  <\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-8\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:0;padding-bottom:var(--wp--preset--spacing--40);padding-left:0;min-height:600px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-327 size-full\" alt=\"Referenzanlage Feuerwehrschalter Firma Ladenburger - Bild w\u00e4hrend Bau - vielen Dank an e.systeme21\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Anlage_Referenz.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Anlage_Referenz.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Anlage_Referenz-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Anlage_Referenz-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Anlage_Referenz-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Anlage_Referenz-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-left alignwide has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-3037c2090aa9711c28cadaad0285b5da\" id=\"zeitversetzte-abschaltung-fur-grossanlagen-und-megawatt-projekte\" style=\"font-size:28px\">Time-Delayed Shutdown for Large-Scale and Megawatt PV Systems<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-right:0;padding-left:0;flex-basis:50%\">\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-33bf26159e46c9211e2521cb223698c3 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-7424c9f0\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.998,1797.179c-494.704,0-897.173-402.472-897.173-897.173c0-494.708,402.469-897.184,897.173-897.184 c494.708,0,897.179,402.476,897.179,897.184C1797.177,1394.707,1394.705,1797.179,899.998,1797.179z M899.998,65.818 c-459.966,0-834.176,374.215-834.176,834.188c0,459.964,374.21,834.176,834.176,834.176c459.97,0,834.183-374.212,834.183-834.176 C1734.181,440.033,1359.968,65.818,899.998,65.818z\"><\/path><path d=\"M899.998,1641.189c-408.689,0-741.183-332.492-741.183-741.184c0-408.695,332.494-741.194,741.183-741.194 c408.693,0,741.19,332.499,741.19,741.194C1641.188,1308.697,1308.69,1641.189,899.998,1641.189z M899.998,221.808 c-373.955,0-678.187,304.239-678.187,678.198c0,373.954,304.232,678.186,678.187,678.186 c373.957,0,678.193-304.231,678.193-678.186C1578.19,526.047,1273.954,221.808,899.998,221.808z\"><\/path><path d=\"M1408.631,842.445H973.452v-435.18c0-37.471-30.486-67.963-67.952-67.963h-7.172 c-37.457,0-67.953,30.493-67.953,67.963v503.141v7.154v0.008c0,37.476,30.496,67.963,67.953,67.963h7.172l0.052-0.009h503.079 c37.466,0,67.955-30.479,67.955-67.962v-7.154C1476.586,872.939,1446.097,842.445,1408.631,842.445z M880.452,407.265 c0-9.859,8.015-17.883,17.876-17.883h7.172c9.843,0,17.875,8.024,17.875,17.883v435.18h-25.047 c-6.178,0-12.164,0.909-17.876,2.469V407.265z M1426.508,917.56c0,9.852-8.034,17.884-17.877,17.884H970.975h-65.448h-7.199 c-9.861,0-17.876-8.032-17.876-17.884v-7.154c0-9.861,8.015-17.879,17.876-17.879h25.047h50.077h435.179 c9.843,0,17.877,8.018,17.877,17.879V917.56z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-56d4522eb0f46573256cfaeab40a215a\" id=\"angepasste-abschaltlogik-fur-grossanlagen\" style=\"font-size:16px\"><strong><strong><strong><strong>Optimised shutdown logic for large photovoltaic systems<\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-205a61eda43a634e00d37b073de08271 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-58aa2286\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.998,1797.179c-494.704,0-897.173-402.472-897.173-897.173c0-494.708,402.469-897.184,897.173-897.184 c494.708,0,897.179,402.476,897.179,897.184C1797.177,1394.707,1394.705,1797.179,899.998,1797.179z M899.998,65.818 c-459.966,0-834.176,374.215-834.176,834.188c0,459.964,374.21,834.176,834.176,834.176c459.97,0,834.183-374.212,834.183-834.176 C1734.181,440.033,1359.968,65.818,899.998,65.818z\"><\/path><path d=\"M899.998,1641.189c-408.689,0-741.183-332.492-741.183-741.184c0-408.695,332.494-741.194,741.183-741.194 c408.693,0,741.19,332.499,741.19,741.194C1641.188,1308.697,1308.69,1641.189,899.998,1641.189z M899.998,221.808 c-373.955,0-678.187,304.239-678.187,678.198c0,373.954,304.232,678.186,678.187,678.186 c373.957,0,678.193-304.231,678.193-678.186C1578.19,526.047,1273.954,221.808,899.998,221.808z\"><\/path><path d=\"M1408.631,842.445H973.452v-435.18c0-37.471-30.486-67.963-67.952-67.963h-7.172 c-37.457,0-67.953,30.493-67.953,67.963v503.141v7.154v0.008c0,37.476,30.496,67.963,67.953,67.963h7.172l0.052-0.009h503.079 c37.466,0,67.955-30.479,67.955-67.962v-7.154C1476.586,872.939,1446.097,842.445,1408.631,842.445z M880.452,407.265 c0-9.859,8.015-17.883,17.876-17.883h7.172c9.843,0,17.875,8.024,17.875,17.883v435.18h-25.047 c-6.178,0-12.164,0.909-17.876,2.469V407.265z M1426.508,917.56c0,9.852-8.034,17.884-17.877,17.884H970.975h-65.448h-7.199 c-9.861,0-17.876-8.032-17.876-17.884v-7.154c0-9.861,8.015-17.879,17.876-17.879h25.047h50.077h435.179 c9.843,0,17.877,8.018,17.877,17.879V917.56z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-48d281fa7e6cf25a26425fd066816b64\" id=\"zeitlich-versetzte-abschaltung-grosser-generatorfelder\" style=\"font-size:16px\"><strong><strong><strong><strong>Time-delayed shutdown of large generator fields<\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-400a06183b454cd1bfe2285f3e47e899 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-6571e137\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M899.998,1797.179c-494.704,0-897.173-402.472-897.173-897.173c0-494.708,402.469-897.184,897.173-897.184 c494.708,0,897.179,402.476,897.179,897.184C1797.177,1394.707,1394.705,1797.179,899.998,1797.179z M899.998,65.818 c-459.966,0-834.176,374.215-834.176,834.188c0,459.964,374.21,834.176,834.176,834.176c459.97,0,834.183-374.212,834.183-834.176 C1734.181,440.033,1359.968,65.818,899.998,65.818z\"><\/path><path d=\"M899.998,1641.189c-408.689,0-741.183-332.492-741.183-741.184c0-408.695,332.494-741.194,741.183-741.194 c408.693,0,741.19,332.499,741.19,741.194C1641.188,1308.697,1308.69,1641.189,899.998,1641.189z M899.998,221.808 c-373.955,0-678.187,304.239-678.187,678.198c0,373.954,304.232,678.186,678.187,678.186 c373.957,0,678.193-304.231,678.193-678.186C1578.19,526.047,1273.954,221.808,899.998,221.808z\"><\/path><path d=\"M1408.631,842.445H973.452v-435.18c0-37.471-30.486-67.963-67.952-67.963h-7.172 c-37.457,0-67.953,30.493-67.953,67.963v503.141v7.154v0.008c0,37.476,30.496,67.963,67.953,67.963h7.172l0.052-0.009h503.079 c37.466,0,67.955-30.479,67.955-67.962v-7.154C1476.586,872.939,1446.097,842.445,1408.631,842.445z M880.452,407.265 c0-9.859,8.015-17.883,17.876-17.883h7.172c9.843,0,17.875,8.024,17.875,17.883v435.18h-25.047 c-6.178,0-12.164,0.909-17.876,2.469V407.265z M1426.508,917.56c0,9.852-8.034,17.884-17.877,17.884H970.975h-65.448h-7.199 c-9.861,0-17.876-8.032-17.876-17.884v-7.154c0-9.861,8.015-17.879,17.876-17.879h25.047h50.077h435.179 c9.843,0,17.877,8.018,17.877,17.879V917.56z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-08b68435b78a8f0626488f90376da3f3\" id=\"verzogerungszeit-je-nach-anlagengrosse-zwischen-1-10-sekunden\" style=\"font-size:16px\"><strong><strong><strong><strong>Adjustable delay times between 1 and 10 seconds depending on system size<\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-2361a4b286d1f36505ad2cb79600b0af wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-color:var(--wp--preset--color--nv-text-dark-bg);border-left-width:1px;background-color:#ffffff08;font-size:16px\">For very large photovoltaic systems with high installed capacity, a time-delayed shutdown sequence can be beneficial. The QFire control system can be configured so that individual generator fields or Switch Boxes are shut down sequentially with a defined time delay.<br>This staged shutdown process helps reduce electrical and mechanical stress and ensures controlled shutdown behaviour in large-scale photovoltaic installations. <\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-465 size-full\" alt=\"Technischer Hintergrund\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-60 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:70px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-8fa37233f9e480ccb5f5c073b64d6e37\" id=\"praxisbeispiel-feuerwehrschalter-q-fire-lite-fur-fassaden-pv-an-hochhausern\">Application Example \u2013 QFire LITE PV Firefighter Safety Switch for Facade PV Systems on High-Rise Buildings<br><\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-955ad735ff21c2b37414acd3577a0d8e is-layout-flex wp-container-core-columns-is-layout-34acad51 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-top has-nv-site-bg-color has-text-color has-link-color wp-elements-f5186bedef42baf7db5c2d48b9bc30f2 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:0;padding-bottom:var(--wp--preset--spacing--50);padding-left:0;flex-basis:33.34%\">\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-9c51af97680240e82549f8ed4777f5e7\" id=\"hochhaus-pv-mit-stringweiser-abschaltung-pro-etage\">High-rise photovoltaic systems with string-level shutdown for each floor<\/h3>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-869c253eb7641b4d68b1833a4f49644d wp-block-paragraph\" style=\"font-size:16px\">Photovoltaic systems installed on high-rise buildings, where individual PV strings are routed separately along the facade and into the building for each floor, create special requirements for DC-side safety and shutdown concepts.<br><br>In such applications, insurers and fire services often require a clearly defined, reproducible and automatically effective shutdown solution in case of fire emergencies. The QFire LITE firefighter safety switch is particularly suitable for these types of installations. <\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/firefighter-switch-for-facade-pv-high-rise\/\" style=\"border-width:1px\">View the reference project: firefighter switches for facade PV \u2192 <\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:33.34%\"><div class=\"wp-block-image q3-duotone\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Zwei-QFire-LITE-Feuerwehrschalter-zur-Abschaltung-mehrerer-PV-Strings-bei-Fassaden-PV.webp\" alt=\"Two QFire LITE firefighter switches for disconnecting several PV strings in a facade PV system. Multiple QFire LITE units allow clear assignment of PV strings to building sections or individual storeys.\" class=\"wp-image-8744\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Zwei-QFire-LITE-Feuerwehrschalter-zur-Abschaltung-mehrerer-PV-Strings-bei-Fassaden-PV.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Zwei-QFire-LITE-Feuerwehrschalter-zur-Abschaltung-mehrerer-PV-Strings-bei-Fassaden-PV-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Zwei-QFire-LITE-Feuerwehrschalter-zur-Abschaltung-mehrerer-PV-Strings-bei-Fassaden-PV-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/07\/Zwei-QFire-LITE-Feuerwehrschalter-zur-Abschaltung-mehrerer-PV-Strings-bei-Fassaden-PV-768x768.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33.33%\">\n<p class=\"dc-card has-neve-text-color-color has-text-color has-background has-link-color wp-elements-c59ee4b973cb31668316544fca6ed880 wp-block-paragraph\" style=\"background-color:#d9d4d43d;font-size:16px\">Typical project requirement<br><br><strong>\u25a0 One PV string per floor with separate building entry point<\/strong><br><br><strong>\u25a0 Different string grouping at the inverter<\/strong><br><br><strong>\u25a0 High requirements for personal and operational safety<\/strong><br><br><strong>\u25a0 Central shutdown option for the fire service<\/strong><br><br><strong>\u25a0 Standards-compliant implementation in accordance with applicable DC switching and fire protection requirements<\/strong><br><\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\"><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-block-cover-is-layout-constrained\">\n<div class=\"wp-block-columns alignwide are-vertically-aligned-top has-neve-text-color-background-color has-background is-layout-flex wp-container-core-columns-is-layout-fe716a59 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--70);padding-right:var(--wp--preset--spacing--80);padding-bottom:var(--wp--preset--spacing--70);padding-left:var(--wp--preset--spacing--80)\">\n<div class=\"wp-block-column is-vertically-aligned-top dc-card has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-color:var(--nv-text-dark-bg);border-left-width:1px;background-color:#262626;padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);flex-basis:100%\">\n<h2 id=\"losungen-fur-unterschiedliche-pv-anlagen\" class=\"wp-block-heading has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-071fc0ddd7c5a0bd4edc20d6fa144378\" style=\"font-size:28px\">Solutions for Different Types of Photovoltaic Systems<\/h2>\n\n\n\n<div style=\"height:9px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-text-align-left has-nv-text-dark-bg-color has-text-color wp-block-paragraph\" style=\"font-size:16px\">PV firefighter safety switches can be integrated into a wide range of photovoltaic system concepts, including:<\/p>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color\" id=\"\u25a0-gewerbliche-pv-anlagen\" style=\"font-size:20px\"><strong>\u25a0<\/strong> Commercial photovoltaic systems<\/h3>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color\" id=\"\u25a0-industrie-und-freiflachenanlagen\" style=\"font-size:20px\"><strong>\u25a0<\/strong> Industrial and ground-mounted solar installations<\/h3>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color\" id=\"\u25a0-dachanlagen-mit-mehreren-wechselrichtern\" style=\"font-size:20px\"><strong>\u25a0<\/strong> Rooftop photovoltaic systems with multiple inverters<\/h3>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-6d40494a99c7bb4864906ecadd9295f4 wp-block-paragraph\" style=\"font-size:16px\">The modular QFire system enables safe shutdown of everything from small commercial PV systems to complex large-scale photovoltaic installations with multiple generator fields.<\/p>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull is-light\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"427\" class=\"wp-block-cover__image-background wp-image-465 size-large\" alt=\"Technischer Hintergrund\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1024x427.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px-1536x640.webp 1536w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background2_1920px.webp 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-dark-bg-background-color has-background-dim-40 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-block-cover-is-layout-constrained\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-b5d35919 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--60);padding-right:var(--wp--preset--spacing--60);padding-bottom:0;padding-left:var(--wp--preset--spacing--60)\">\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<h2 id=\"fur-wen-ist-das-q-fire-big-system-ausgelegt\" class=\"wp-block-heading\">Who Is the QFire BIG System Designed For?<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch-300x300.webp\" alt=\"Customised QFire BIG firefighter safety switch solution for photovoltaic systems\" class=\"wp-image-621\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-BIG-kundenspezfisch.webp 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-75e3d356837537b8210c707c0967c0b4 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-a201e054\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-3e53133b09185f056d7d1a1cb526f9a0\" id=\"planer-und-fachplaner\" style=\"font-size:16px\"><strong><strong><strong><strong><strong>PV planners and consulting engineers<\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-3d7189a17683cbdef45fb76d7e12c171 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-8fb2f8e4\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-14d1f8af3e9c51c64e3a0b609306935e\" id=\"installateure-und-ep-cs\" style=\"font-size:16px\"><strong><strong><strong><strong><strong>Installers and EPC companies<\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-46a4b80752a04a4a1f10040673e62665 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-e2cecf95\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-6b2b67f943141474270f3e531910a6c7\" id=\"betreiber-grosser-pv-anlagen\" style=\"font-size:16px\"><strong><strong><strong><strong><strong>Operators of large-scale photovoltaic systems<\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">The QFire system was specifically developed to meet the requirements of planners, installers and EPC companies.<br>Thanks to its modular architecture, clearly defined system logic and simplified installation concept, the system can be integrated into a wide variety of photovoltaic system designs in compliance with applicable standards. <br><br>The combination of technical safety, scalability and easy handling makes QFire a future-proof solution for photovoltaic systems of all sizes.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<h2 id=\"fur-wen-ist-das-q-fire-lite-system-ausgelegt\" class=\"wp-block-heading\">Who Is the QFire LITE System Designed For?<\/h2>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung-300x300.webp\" alt=\"QFire LITE firefighter safety switch for photovoltaic systems \u2013 standardised and cost-efficient solution\" class=\"wp-image-622\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung.webp 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-732398fb40f3a558dc343f938f92305b is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-9b75e8fd\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-d33584f01df820f2a4e0b5951c8bda0a\" id=\"installateure-und-fachbetriebe\" style=\"font-size:16px\"><strong><strong><strong><strong><strong><strong>Installers and specialised electrical contractors<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-0d72e30da31ab193449b93df0a9331a2 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-32546b36\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-bcb9c75cd0889f399b681435d3adc16e\" id=\"planer-kleinerer-pv-anlagen\" style=\"font-size:16px\"><strong><strong><strong><strong><strong><strong>Planners of smaller photovoltaic systems<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-neve-text-color-color has-text-color has-link-color wp-elements-7c2abfca3bff53c735612455d4a1cff1 is-nowrap is-layout-flex wp-container-core-group-is-layout-6e81cd72 wp-block-group-is-layout-flex\" style=\"padding-top:0;padding-bottom:0\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-278a8b88\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M872.831,1326.446c-1.999,0.113-3.853-0.183-5.733-0.53c-6.064-1.076-11.863-3.945-16.53-8.611 l-514.859-514.86c-5.852-5.855-9.138-13.792-9.138-22.068c0-8.275,3.287-16.212,9.142-22.067L455.5,638.535 c12.189-12.185,31.954-12.185,44.126,0l373.109,373.1l727.884-727.89c12.189-12.185,31.949-12.185,44.131,0l119.788,119.784 c5.855,5.851,9.142,13.792,9.142,22.067s-3.286,16.212-9.137,22.063l-869.649,869.645 C889.043,1323.155,881.106,1326.446,872.831,1326.446z M401.905,780.377l470.825,470.83l825.614-825.61l-75.657-75.653 l-727.885,727.889c-12.19,12.186-31.95,12.186-44.13,0L477.563,704.729L401.905,780.377z\"><\/path><path d=\"M1692.376,662.67c22.568,75.209,34.758,154.872,34.758,237.334c0,456.08-371.054,827.129-827.138,827.129 c-456.08,0-827.129-371.05-827.129-827.129c0-456.084,371.049-827.138,827.129-827.138c213.186,0,407.787,81.086,554.605,214.022 l44.161-44.165C1340.604,98.513,1130.391,10.456,899.996,10.456c-490.494,0-889.54,399.051-889.54,889.548 s399.046,889.54,889.54,889.54c490.498,0,889.548-399.042,889.548-889.54c0-100.372-16.734-196.909-47.517-286.985 L1692.376,662.67z\"><\/path><\/svg><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-4d4af445ee63772779a2e8635b70f546\" id=\"grosshandel\" style=\"font-size:16px\"><strong><strong><strong><strong><strong><strong>Electrical wholesalers and distribution partners<\/strong><\/strong><\/strong><\/strong><\/strong><\/strong><\/h3>\n<\/div>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">The QFire LITE system is the standardised solution for small and medium-sized photovoltaic systems. It is based on the same proven safety principle as QFire BIG, but designed as a compact, non-expandable solution. <br><br>QFire LITE is particularly suitable for straightforward photovoltaic system concepts where simple integration, a limited number of strings, clear system structures and cost-efficient implementation are key priorities.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-2518fc00 wp-block-columns-is-layout-flex\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--60);padding-bottom:0;padding-left:var(--wp--preset--spacing--60)\">\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<div class=\"wp-block-buttons is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-fe48e5de wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color has-border-color has-neve-text-color-border-color has-text-align-center wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\" style=\"border-width:1px\">View QFire BIG Product \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<div class=\"wp-block-buttons is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-fe48e5de wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color has-border-color has-neve-text-color-border-color has-text-align-center wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-lite-firefighter-switch\/\" style=\"border-width:1px\">View QFire LITE Product \u2192<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\" id=\"dcac\"><img loading=\"lazy\" decoding=\"async\" width=\"1058\" height=\"800\" class=\"wp-block-cover__image-background wp-image-812 size-full\" alt=\"Cluster Steuerbox f\u00fcr mehrere Generatorfl\u00e4chen\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp 1058w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-300x227.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-1024x774.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-768x581.webp 768w\" sizes=\"auto, (max-width: 1058px) 100vw, 1058px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-1ec003498444417517729020dbde4028\" id=\"kombinierte-dc-und-ac-abschaltung-bei-grossen-pv-anlagen\" style=\"border-style:none;border-width:0px;font-size:28px\">Combined DC and AC shutdown for large PV systems<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-90766552b19a69851a48321f7074a7d8 is-layout-flex wp-container-core-columns-is-layout-0e642418 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:0;padding-bottom:var(--wp--preset--spacing--40);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-top has-nv-site-bg-color has-text-color has-link-color wp-elements-064324a49e90b8b115cc0d8d40fafa33 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:0;padding-bottom:0;padding-left:0;flex-basis:50%\">\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\"><strong>In large PV systems, industrial projects and solar parks, the shutdown concept often has to be considered beyond the DC side alone. In practice, it may be necessary to disconnect the PV strings on the DC side close to the generator and, at the same time, shut down or block the AC side of the inverter or the feed-in path in a controlled manner. <\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">QFire BIG can be integrated into such an overall shutdown concept. The QFire switch boxes provide generator-side galvanic isolation of the DC strings according to IEC 60947-3. In addition, the status contact of the QFire control box can be used project-specifically to provide an external AC-side shutdown signal \u2013 for example to a grid and system protection relay, an inverter enable input or a site-specific contactor solution. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">This makes QFire BIG particularly suitable for large commercial PV systems, megawatt projects, solar parks, industrial buildings and hybrid systems where DC string disconnection and AC-side enable interruption should not be considered separately.<\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"warum-ist-bei-grossen-pv-anlagen-eine-kombinierte-dc-und-ac-abschaltung-sinnvoll\" class=\"wp-block-heading\">Why is combined DC and AC shutdown useful in large PV systems?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In simple PV systems, it is often sufficient to disconnect the DC cables at a defined disconnection point. In larger installations or hybrid systems, the situation can be different. If, for example, a battery storage system is connected to the inverter or to the DC link, the DC link may remain charged. In unfavourable cases, this can lead to measurable voltage between the DC string cables and earth, even though the DC-side PV generator disconnection has already been triggered.   <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For this reason, it can be useful or necessary in such systems to integrate both the DC side and the AC side into the shutdown concept at the same time. QFire BIG disconnects the PV strings on the DC side close to the generator. In parallel, an AC-side shutdown or enable circuit can be controlled via the status contact of the control box. This helps prevent the DC and AC side from reacting independently of each other during a shutdown sequence.   <\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"kann-q-fire-big-einen-na-schutz-oder-eine-wechselrichter-freigabe-ansteuern\" class=\"wp-block-heading\">Can QFire BIG control a grid and system protection relay or inverter enable signal?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Yes. Depending on the project, the status contact of the QFire control box can be used to control external components. Typical applications include integration into a grid and system protection relay, an enable signal at the inverter or a site-specific contactor control on the AC side. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In practice, the potential-free status contact is not used as a power switch, but as a signal or enable contact. For example, it can be integrated into the enable circuit of the grid and system protection relay. When QFire is switched off, the AC-side enable can also be interrupted at the same time. The grid and system protection relay or the downstream contactor solution then performs the actual AC-side shutdown.   <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The exact wiring depends on the grid and system protection relay used, the inverter, the grid connection concept and the project requirements.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top has-nv-text-dark-bg-color has-neve-text-color-background-color has-text-color has-background has-link-color wp-elements-1e7d1181a7d3c273e6877268445866c5 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50);flex-basis:50%\">\n<h3 id=\"wie-funktioniert-das-abschaltkonzept-in-der-praxis\" class=\"wp-block-heading\">How does the shutdown concept work in practice?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">During a shutdown, QFire BIG performs the DC-side function: the connected PV strings are galvanically disconnected at the switch box close to the generator. This disconnects the DC cables from the QFire switch box towards the inverter. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">At the same time, the status contact of the control box can be used as a signal for the AC side. This signal can, for example, influence a grid and system protection relay, an inverter input or an external contactor control. In a typical setup, the grid and system protection relay then controls the AC contactors so that the feed-in path or AC path is also disconnected or blocked.  <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This creates a coordinated shutdown concept: on the DC side, QFire BIG disconnects the PV strings; on the AC side, the enable signal or feed-in path is interrupted via the external components provided for this purpose.<\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"fur-welche-anlagen-ist-die-kombinierte-dc-und-ac-abschaltung-besonders-relevant\" class=\"wp-block-heading\">For which systems is combined DC and AC shutdown particularly relevant?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Combined shutdown is particularly relevant for larger and more complex system structures. These include commercial rooftop systems, industrial PV systems, megawatt solar parks, PV systems with several inverters, hybrid systems with battery storage, systems with a central grid connection point and projects with special requirements regarding fire safety, grid connection or operational safety. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In such projects, EPCs and planners must ensure that the shutdown does not only work at one single component, but fits the overall system concept. QFire BIG provides the DC-side PV generator disconnection and the option of integrating AC-side shutdown logic via the status contact. <\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"was-ist-bei-der-planung-zu-beachten\" class=\"wp-block-heading\">What should be considered during planning?<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The AC-side shutdown is not carried out directly by the QFire switch box as a power switching device. QFire BIG provides the DC-side galvanic isolation and can supply a signal for the AC-side shutdown logic via the status contact of the control box. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The design of the AC components \u2013 for example grid and system protection relay, AC contactors, inverter enable, grid connection and protection concept \u2013 is always project-specific. The specifications of the inverter manufacturer, the requirements of the grid operator, the grid connection concept and the applicable technical rules must be taken into account. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For large PV systems, combined DC and AC shutdown should therefore be considered early in the planning process. This allows the switching logic, status indication, emergency stop concept, control cable, grid and system protection relay and inverter enable to be coordinated properly. <\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div>\n<\/div>\n\n\n\n<p class=\"alignwide dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-1746036b402846d4b513b23c3bb8f880 wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-color:var(--wp--preset--color--nv-text-dark-bg);border-left-width:1px;background-color:#ffffff08;font-size:16px\"><strong>Note on AC-side shutdown<br>QFire BIG does not replace the grid and system protection relay or the site-specific AC switching equipment. However, the QFire control box can provide a signal for external AC components via the status contact. The exact implementation is always project-specific and depends on the system concept, inverter specifications, grid connection conditions and the applicable local technical requirements.  <\/strong><\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"373\" class=\"wp-block-cover__image-background wp-image-3303 size-large\" alt=\"\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/03\/Presse-1024x373.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/03\/Presse-1024x373.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/03\/Presse-300x109.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/03\/Presse-768x280.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/03\/Presse-1536x560.webp 1536w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/03\/Presse.webp 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-block-cover-is-layout-constrained\">\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-b164b6e8 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--70);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--70);padding-left:var(--wp--preset--spacing--50)\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-2e652a5723f884b2e155efcf6162903d wp-block-paragraph\" style=\"font-size:28px\"><strong>Fachbeitr\u00e4ge &amp; Pressemeldungen zum Feuerwehrschalter f\u00fcr Photovoltaik<\/strong><\/p>\n\n\n\n<p class=\"has-text-align-left has-neve-text-color-color has-text-color has-link-color wp-elements-c288400474a0ae9f5f91b5fdcabf8d8f wp-block-paragraph\" style=\"font-size:16px\">Der Einsatz von Feuerwehrschaltern in Photovoltaik-Anlagen wird in der Branche intensiv diskutiert \u2013 insbesondere im Hinblick auf Sicherheit, Normung und Einsatz im Brandfall. Hier finden Sie ausgew\u00e4hlte Fachberichte, Branchenmeldungen und technische Einordnungen.<\/p>\n\n\n\n<div class=\"press-links\">\n\n<a href=\"https:\/\/www.solarserver.de\/2026\/06\/12\/intersolar-2026-q3-energie-praesentiert-ki-konfigurator-fuer-photovoltaik-feuerwehrschalter\/\" target=\"_blank\" class=\"press-item\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/04\/solarserver-logo-042d89.svg\" alt=\"\" title=\"\">\n<h3>Intersolar 2026: Q3 Energie pr\u00e4sentiert KI-Konfigurator f\u00fcr Photovoltaik-Feuerwehrschalter<\/h3>\n<span class=\"press-arrow\">\u2192<\/span>\n<\/a>\n\n<a href=\"https:\/\/www.solarserver.de\/2025\/01\/29\/wann-ist-ein-feuerwehrschalter-bei-photovoltaik-anlagen-notwendig\/\" target=\"_blank\" class=\"press-item\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/04\/solarserver-logo-042d89.svg\" alt=\"\" title=\"\">\n<h3>Wann ist ein Feuerwehrschalter bei Photovoltaik-Anlagen notwendig?<\/h3>\n<span class=\"press-arrow\">\u2192<\/span>\n<\/a>\n\n<a href=\"https:\/\/www.elektro.net\/125702\/generatorfreischaltung-mit-dem-feuerwehrschalter\/\" target=\"_blank\" class=\"press-item\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/04\/logo-elektro-net-2d5199.svg\" alt=\"\" title=\"\">\n<h3>Generatorfreischaltung mit dem Feuerwehrschalter<\/h3>\n<span class=\"press-arrow\">\u2192<\/span>\n<\/a>\n\n<a href=\"https:\/\/www.pv-magazine.de\/unternehmensmeldungen\/q3-pv-feuerwehrschalter-qfire-erhaelt-zertifizierung-nach-iec-60947-3-angebot-planerschulung\/\" target=\"_blank\" class=\"press-item\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/03\/logo.webp\" alt=\"\" title=\"\">\n<h3>Q3 PV-Feuerwehrschalter \u201eQFire\u201c erh\u00e4lt Zertifizierung nach IEC 60947-3 <\/h3>\n<span class=\"press-arrow\">\u2192<\/span>\n<\/a>\n\n<a href=\"https:\/\/www.pv-magazine.de\/unternehmensmeldungen\/qfire-pv-feuerwehrschalter-schulung-praxisnahe-schulung-fuer-planer-und-installateure\/\" target=\"_blank\" class=\"press-item\" rel=\"noopener\">\n<img decoding=\"async\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/03\/logo.webp\" alt=\"\" title=\"\">\n<h3>QFire PV Feuerwehrschalter Schulung: Praxisnahe Schulung f\u00fcr Planer und Installateure<\/h3>\n<span class=\"press-arrow\">\u2192<\/span>\n<\/a>\n\n<\/div>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"427\" class=\"wp-block-cover__image-background wp-image-454 size-large\" alt=\"Technische Details\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1536x640.webp 1536w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp 1920w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-90 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-container-core-cover-is-layout-a48333fe wp-block-cover-is-layout-constrained\">\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-5b0bc1de wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<h2 id=\"you-tube-video-q-3-erklart-q-fire-feuerwehrschalter-pv-sichere-dc-seitige-abschaltung-im-brandfall\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-c8799bae5a583e7589e751a925bcca37\" style=\"font-size:28px\">Q3 YouTube Video Explains the QFire PV Firefighter Safety Switch \u2013 Safe DC-Side Shutdown in Fire Emergencies<\/h2>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-bfd20d10d862e1169cd90f7f309b9dda wp-block-paragraph\" style=\"font-size:16px\">Building insurers, authorities and fire services increasingly require automatic shutdown solutions for photovoltaic systems during fire emergencies or rescue operations. The main concern is the dangerous DC voltage that may remain present in the DC cables even after the building\u2019s AC power supply has been disconnected. <\/p>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-9c10d9b7c1cb4c87049edd1326ff1ff5 wp-block-paragraph\" style=\"font-size:16px\">The firefighter safety switch enables safe DC-side shutdown of the PV strings directly at the building entry point or roof entry area. The system is triggered via a defined control interface, for example by disconnecting the building power supply, using an external firefighter emergency button or through connection to a fire alarm system. During activation, the PV strings are galvanically isolated so that no dangerous DC voltage is routed into the building.  <\/p>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-deba2d2f21de9ec2cc49e88896ea25a6 wp-block-paragraph\">Once the power supply is restored after an emergency event, the system can automatically restart. Manual intervention at the photovoltaic system or on the roof is not required in this case. This ensures both operational safety and emergency response safety for the photovoltaic installation.  <\/p>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-a319e62e4432ba00463b153f03250fa9 wp-block-paragraph\">The video clearly demonstrates the operating principle of a PV firefighter safety switch in a practical application scenario.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50)\">\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<div class=\"nv-iframe-embed\"><iframe title=\"\ud83d\udd25 Warum braucht man einen Feuerwehrschalter? QFire - Sicherheit f\u00fcr Photovoltaikanlagen | Q3 erkl\u00e4rt\" width=\"1200\" height=\"675\" src=\"https:\/\/www.youtube.com\/embed\/2MYO5_F8zg8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n<\/div><\/figure>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-9\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);min-height:600px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"700\" class=\"wp-block-cover__image-background wp-image-676 size-full\" alt=\"Photovoltaik Feuerwehrschalter Schulung\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Online-Training-Hintergrund.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Online-Training-Hintergrund.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Online-Training-Hintergrund-300x109.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Online-Training-Hintergrund-1024x373.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Online-Training-Hintergrund-768x280.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Online-Training-Hintergrund-1536x560.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h2 id=\"online-schulung-q-fire-feuerwehrschalter-pv\" class=\"wp-block-heading\" style=\"font-size:28px\">Online Training for the QFire PV Firefighter Safety Switch<\/h2>\n\n\n\n<p class=\"has-nv-site-bg-color has-text-color has-link-color wp-elements-52630e126b62a860f475ab47dade1f4d wp-block-paragraph\" style=\"font-size:16px\">Planning and installing firefighter safety switches for photovoltaic systems requires a solid understanding of technical operating principles, applicable standards and practical implementation. The QFire training programme provides practical expertise covering DC-side PV string shutdown, system integration and typical planning and installation requirements.  <br><br>The training is intended for planners, specialised electrical contractors and technical decision-makers who are responsible for specifying, installing or evaluating firefighter safety switch systems.<\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-container-core-buttons-is-layout-00436373 wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/training-on-firefighter-switches-for-pv-systems\/\" style=\"border-width:1px\">Technical Training for the QFire Firefighter Safety Switch \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33%\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium\"><a href=\"https:\/\/q3-energie.de\/en\/knowledge\/training-on-firefighter-switches-for-pv-systems\/\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Feuerwehrschalter-PV-Online-Schulung-fuer-Planer-und-Installateure-300x300.webp\" alt=\"Firefighter Switch PV \u2013 Online Training for Planners and Installers\" class=\"wp-image-921\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Feuerwehrschalter-PV-Online-Schulung-fuer-Planer-und-Installateure-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Feuerwehrschalter-PV-Online-Schulung-fuer-Planer-und-Installateure-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Feuerwehrschalter-PV-Online-Schulung-fuer-Planer-und-Installateure.webp 600w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a><\/figure>\n<\/div><\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-b3078a59 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--60);padding-bottom:var(--wp--preset--spacing--60)\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33%\"><div class=\"wp-block-image q3-duotone\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"600\" height=\"500\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wechselrichter-mit-integriertem-DC-Freischalter.webp\" alt=\"Inverter with integrated DC isolator\" class=\"wp-image-904\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wechselrichter-mit-integriertem-DC-Freischalter.webp 600w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wechselrichter-mit-integriertem-DC-Freischalter-300x250.webp 300w\" sizes=\"auto, (max-width: 600px) 100vw, 600px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<h2 id=\"wann-ist-ein-feuerwehrschalter-pflicht\" class=\"wp-block-heading\">When is a firefighter switch mandatory?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Whether a firefighter switch is required for a PV system depends on the specific installation. Key factors include cable routes, building type, fire protection concept, regional requirements and tender specifications. For long DC cable routes inside the building or for larger commercial PV systems, generator-side disconnection is often technically advisable and frequently required in practice.  <\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-container-core-buttons-is-layout-00436373 wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color has-border-color has-neve-text-color-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/pv-firefighter-switch-requirements\/\" style=\"border-width:1px\">Understand PV firefighter switch standards &amp; requirements \u2192<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull wp-duotone-unset-10\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--50);min-height:600px;aspect-ratio:unset;\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"700\" class=\"wp-block-cover__image-background wp-image-682 size-full\" alt=\"FAQ \u2013 Feuerwehrschalter und Brandschutz bei PV-Anlagen\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/FAQ-\u2013-Feuerwehrschalter-und-Brandschutz-bei-PV-Anlagen.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/FAQ-\u2013-Feuerwehrschalter-und-Brandschutz-bei-PV-Anlagen.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/FAQ-\u2013-Feuerwehrschalter-und-Brandschutz-bei-PV-Anlagen-300x109.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/FAQ-\u2013-Feuerwehrschalter-und-Brandschutz-bei-PV-Anlagen-1024x373.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/FAQ-\u2013-Feuerwehrschalter-und-Brandschutz-bei-PV-Anlagen-768x280.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/FAQ-\u2013-Feuerwehrschalter-und-Brandschutz-bei-PV-Anlagen-1536x560.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-site-bg-background-color has-background-dim-80 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-b3078a59 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--60);padding-bottom:var(--wp--preset--spacing--60)\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<h2 id=\"faq-feuerwehrschalter-und-brandschutz-bei-pv-anlagen\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-dbc746e9b2c9083d0d6346ed4092dccc\" style=\"font-size:28px\">FAQ \u2013 PV Firefighter Safety Switches and Fire Protection for Photovoltaic Systems<\/h2>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-4bb579c2b9ca65607ce63f2d6baa0eeb wp-block-paragraph\" style=\"font-size:16px\">In connection with firefighter safety switches for photovoltaic systems, technical, normative and legal questions frequently arise in practice. These topics particularly include DC-side shutdown concepts, the distinction between string-level and module-level shutdown, integration into fire protection concepts and the question of whether firefighter safety switches are mandatory. <\/p>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-8c851bf2cd8d713f9313b8d7421bca64 wp-block-paragraph\" style=\"font-size:16px\">As there is no universal legal requirement, the use of firefighter safety switches often depends on the specific application, the photovoltaic system design, the responsible authorities and applicable standards or recommendations. The following questions and answers are intended to provide professional guidance and address common uncertainties relating to the planning, installation and operation of photovoltaic systems. <\/p>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-234ec78d0a401773161b158a14055fa2 wp-block-paragraph\" style=\"font-size:16px\">The following FAQ section summarises the most important technical and regulatory aspects relating to firefighter safety switches for photovoltaic systems and serves as a practical guide for planning, installation and operation.<\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-container-core-buttons-is-layout-00436373 wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-secondary dc-card\"><a class=\"wp-block-button__link has-neve-text-color-color has-text-color has-link-color has-border-color has-neve-text-color-border-color has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/faq-pv-firefighter-switch\/\" style=\"border-width:1px\">Frequently Asked Questions About PV Firefighter Safety Switches and Fire Protection \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:33%\">\n<figure class=\"wp-block-image size-full q3-duotone\"><a href=\"https:\/\/q3-energie.de\/en\/knowledge\/faq-pv-firefighter-switch\/\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"400\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter.webp\" alt=\"Firefighter Switch FAQ\" class=\"wp-image-1731\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter-150x150.webp 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/a><\/figure>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns animated fadeIn is-layout-flex wp-container-core-columns-is-layout-4c3d31c9 wp-block-columns-is-layout-flex\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-top:0;padding-right:0;padding-bottom:0;padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-top animated fadeIn q3-start-kachel dc-card is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30)\">\n<div class=\"wp-block-cover aligncenter has-custom-content-position is-position-bottom-center\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"400\" class=\"wp-block-cover__image-background wp-image-314 size-full\" alt=\"QFire Feuerwehrschalter f\u00fcr 8 Strings mit \u00dcberspannungsschutz T1+2\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire_Feuerwehrschalter_8-Strings_400px-150x150.webp 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-link-color-background-color has-background-dim-70 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-container-core-cover-is-layout-0255ba1e wp-block-cover-is-layout-constrained\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-127246d962d0db155c0837f690d1fc14\" id=\"planung-ausschreibung\" style=\"font-size:16px\"><strong>Planning &amp; Specification<\/strong><\/h3>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center has-nv-site-bg-color has-text-color has-link-color wp-elements-cf035f3e3431d92df841341ff9509932\" id=\"fur-fachplaner-planungsburos\" style=\"font-size:30px\">For Consulting Engineers and Planning Offices<\/h2>\n\n\n\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-73f63f81f165e6dd3b0d2d57b71fbc33 wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-color:var(--nv-c-2);border-left-color:var(--nv-text-dark-bg);border-left-style:solid;border-left-width:5px;background-color:#004d99a1;padding-right:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);font-size:16px\">Normative guidance, planning recommendations and specification texts for firefighter safety switches in modern photovoltaic systems.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-container-core-buttons-is-layout-00436373 wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/wissen\/pflicht\/\">Requirements &amp; Obligations for Firefighter Safety Switches \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/downloads\/qfire-firefighter-switch-iec-60947-3-data-sheets\/\">Firefighter Safety Switch Specification Texts \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 undefined is-style-primary\"><a class=\"wp-block-button__link has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/training-on-firefighter-switches-for-pv-systems\/\">Training for PV Firefighter Safety Switch Planners \u2192<\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top animated fadeIn q3-start-kachel dc-card is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30)\">\n<div class=\"wp-block-cover aligncenter has-custom-content-position is-position-bottom-center\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"400\" class=\"wp-block-cover__image-background wp-image-1113 size-full\" alt=\"GAK mit \u00dcberspannungsschutz DC Anschlusstechnik kundenspezifisch f\u00fcr x MPP Tracker optional mit Sicherungen, DC Freischalter\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Ueberspannungsschutz_GAK_400px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Ueberspannungsschutz_GAK_400px.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Ueberspannungsschutz_GAK_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Ueberspannungsschutz_GAK_400px-150x150.webp 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-link-color-background-color has-background-dim-70 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-container-core-cover-is-layout-0255ba1e wp-block-cover-is-layout-constrained\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-3a1fb7f0e2d8ca1579efa474c1e1aa06\" id=\"montage-inbetriebnahme\" style=\"font-size:16px\"><strong>Installation &amp; Commissioning<\/strong><\/h3>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center has-nv-site-bg-color has-text-color has-link-color wp-elements-e1718d84f5d144aa74e18ef00b8855e2\" id=\"fur-fachplaner-installateure\" style=\"font-size:32px\"><strong>For Consulting Engineers and Installers<\/strong><\/h2>\n\n\n\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-0a598fbbdb45b31725371e07010904aa wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-color:var(--nv-c-2);border-left-color:var(--nv-text-dark-bg);border-left-style:solid;border-left-width:5px;background-color:#004d99a1;padding-right:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);font-size:16px\">Technical fundamentals for the professional installation and commissioning of firefighter safety switches.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/downloads\/qfire-firefighter-switch-iec-60947-3-data-sheets\/\">Technical Data for the QFire Firefighter Safety Switch \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\">Training for Planners &amp; Installers \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/\">Submit Project Inquiry \u2192<\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top animated fadeIn q3-start-kachel dc-card has-large-font-size is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--30);padding-bottom:var(--wp--preset--spacing--30);padding-left:var(--wp--preset--spacing--30)\">\n<div class=\"wp-block-cover aligncenter has-custom-content-position is-position-bottom-center\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-top:0;padding-right:var(--wp--preset--spacing--50);padding-bottom:0;padding-left:var(--wp--preset--spacing--50)\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"400\" class=\"wp-block-cover__image-background wp-image-316 size-full\" alt=\"AC Box AC Anschlusstechnik mit \u00dcberspannungsschutz und NH Trenner 250 A TN-C\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/AC-Box_250A_TN-C_NH-Trenner_Ueberspannungsschutz_400px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/AC-Box_250A_TN-C_NH-Trenner_Ueberspannungsschutz_400px.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/AC-Box_250A_TN-C_NH-Trenner_Ueberspannungsschutz_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/AC-Box_250A_TN-C_NH-Trenner_Ueberspannungsschutz_400px-150x150.webp 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-link-color-background-color has-background-dim-70 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-container-core-cover-is-layout-0255ba1e wp-block-cover-is-layout-constrained\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-b84a7ddcd2da671923e65d5daa576a19\" id=\"produkte-vertrieb\" style=\"font-size:16px\"><strong>Produkte &amp; Vertrieb<\/strong><\/h3>\n\n\n\n<h2 class=\"wp-block-heading has-text-align-center has-nv-site-bg-color has-text-color has-link-color wp-elements-1be763c83d529cd40887974237892b69\" id=\"fur-grosshandel-vertriebspartner\" style=\"font-size:32px\"><strong>For Wholesalers and Distribution Partners<\/strong><\/h2>\n\n\n\n<p class=\"dc-card has-nv-text-dark-bg-color has-text-color has-background has-link-color wp-elements-61462f5818213553125293cb13ce37c1 wp-block-paragraph\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-right-color:var(--nv-c-2);border-left-color:var(--nv-text-dark-bg);border-left-style:solid;border-left-width:5px;background-color:#004d99a1;padding-right:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40);font-size:16px\">Overview of product variants, technical configurations and answers to frequently asked questions about PV firefighter safety switches.<\/p>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-text-align-center has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\">View QFire BIG Product (Modular System) \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-text-align-center has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-lite-firefighter-switch\/\">View QFire LITE Product \u2192<\/a><\/div>\n\n\n\n<div class=\"wp-block-button has-custom-width wp-block-button__width-100 is-style-primary\"><a class=\"wp-block-button__link has-text-align-center has-small-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/faq-pv-firefighter-switch\/\">PV Firefighter Safety Switch FAQ \u2192<\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>What is a PV Firefighter Safety Switch? A PV firefighter safety switch is a safety device designed to selectively disconnect photovoltaic DC circuits at string level. It is intended to protect firefighters, emergency responders and service personnel, particularly during fires or rescue operations in buildings equipped with photovoltaic systems. Because PV modules continuously generate DC&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":7193,"parent":7465,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","neve_meta_reading_time":"","_themeisle_gutenberg_block_has_review":false,"footnotes":""},"class_list":["post-7342","page","type-page","status-publish","has-post-thumbnail","hentry"],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7342","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/comments?post=7342"}],"version-history":[{"count":23,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7342\/revisions"}],"predecessor-version":[{"id":9410,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7342\/revisions\/9410"}],"up":[{"embeddable":true,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7465"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/media\/7193"}],"wp:attachment":[{"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/media?parent=7342"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}