{"id":7507,"date":"2026-01-28T17:51:38","date_gmt":"2026-01-28T16:51:38","guid":{"rendered":"https:\/\/q3-energie.de\/pv-connection-technology-products-firefighter-switches-generator-junction-boxes-ac-dc-boxes\/qfire-lite-firefighter-switch\/"},"modified":"2026-07-21T16:30:27","modified_gmt":"2026-07-21T14:30:27","slug":"qfire-lite-firefighter-switch","status":"publish","type":"page","link":"https:\/\/q3-energie.de\/en\/products\/qfire-lite-firefighter-switch\/","title":{"rendered":"QFire LITE PV Firefighter Switch for 2 or 4 PV Strings"},"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-background-dim-70 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-q-fire-lite-fur-pv-anlagen\">QFire LITE PV Firefighter Switch for 2 or 4 PV Strings<\/h1>\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\" id=\"standardisierte-dc-seitige-string-abschaltung-fur-kleine-und-mittlere-photovoltaik-anlagen-kompakt-normkonform-und-einfach-integrierbar\" style=\"font-size:18px\"><strong>Compact DC string isolation for 2 or 4 PV strings \u2013 galvanic isolation in accordance with IEC 60947-3, up to 1,500 V DC and automatic reconnection when the AC supply is restored.<\/strong><\/p>\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\" 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)\">Functional Principle &amp; Shutdown Logic \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=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/qfire-pv-firefighter-switch\/\" 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)\">Submit a QFire LITE Enquiry \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=\"#unterschied\" 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)\">Difference between QFire LITE vs. QFire BIG \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=\"https:\/\/q3-energie.de\/en\/downloads\/qfire-firefighter-switch-iec-60947-3-data-sheets\/\" 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)\">Download Technical Data \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\">\n<figure class=\"wp-block-image 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-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung.webp\" alt=\"QFire LITE PV Firefighter Switch for 2 or 4 PV Strings\" class=\"wp-image-622\" style=\"width:400px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung.webp 400w, 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\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/figure>\n<\/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-a3169544411592554dda7ac6462343f3\" id=\"rank-math-toc\"><h2>Auf dieser Seite<\/h2><nav><ul><li class=\"\"><a href=\"#kompakte-dc-fernabschaltung-fur-kleine-und-mittlere-pv-anlagen\">Compact Remote DC Isolation for Standardised PV Applications<\/a><ul><li class=\"\"><a href=\"#q-fire-lite-auf-einen-blick\">QFire LITE at a Glance<\/a><\/li><\/ul><\/li><li class=\"\"><a href=\"#so-funktioniert-der-feuerwehrschalter-pv-q-fire-lite\">How the QFire LITE Works<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#standard\">Technical Data QFire LITE<\/a><\/li><li class=\"\"><a href=\"#automatisches-wiederzuschalten\">Automatic Reconnection<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#praxis\">PV System Safety Architecture<\/a><ul><\/ul><\/li><li class=\"\"><a href=\"#haufige-fragen-zum-feuerwehrschalter-q-fire-lite\">Frequently Asked Questions About the QFire LITE PV Firefighter Switch<\/a><\/li><li class=\"\"><a href=\"#projektanfrage-feuerwehrschalter-q-fire-lite\">QFire LITE Project Enquiry<\/a><ul><\/ul><\/li><\/ul><\/nav><\/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-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:70%\">\n<h2 id=\"kompakte-dc-fernabschaltung-fur-kleine-und-mittlere-pv-anlagen\" class=\"wp-block-heading\">QFire LITE PV Firefighter Switch: <strong>Compact Remote DC Isolation for Standardised PV Applications<\/strong><\/h2>\n\n\n\n<h3 id=\"q-fire-lite-ist-ein-kompakter-pv-feuerwehrschalter-fur-standardisierte-anlagen-mit-2-oder-4-pv-strings-das-gerat-wird-generatornah-beziehungsweise-am-eintritt-der-dc-leitungen-in-das-gebaude-installiert-und-trennt-im-auslosefall-plus-und-minusleiter-jedes-angeschlossenen-strings-galvanisch\" class=\"wp-block-heading\"><strong>QFire LITE is a compact PV firefighter safety switch for standardised applications with 2 or 4 PV strings. It is installed close to the PV array or at the point where the DC cables enter the building and galvanically isolates the positive and negative conductors of every connected string when activated. <\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">QFire LITE PV Firefighter Switch is particularly suitable for rooftop systems, fa\u00e7ade PV and repeatable system designs with 2 or 4 PV strings per isolation point. It is designed for system voltages up to 1,500 V DC and short-circuit currents up to 20 A Isc per string.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Unlike firefighter switches that use a mechanically latched switch-disconnector, QFire LITE automatically reconnects the PV strings when the AC supply is restored. Manual access to the device is therefore not required following routine mains interruptions. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Four clearly defined variants are available: QFire LITE for 2 or 4 PV strings, each optionally available with integrated Type 1+2 DC surge protection.<\/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-table aligncenter is-style-stripes\"><table class=\"has-fixed-layout\"><tbody><tr><td><img decoding=\"async\" style=\"width: 200px;\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-2-Strings-300x300.webp\" alt=\"QFire LITE 2 PV firefighter switch for two PV strings without surge protection\" title=\"\"><\/td><td><img decoding=\"async\" style=\"width: 200px;\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-2-Strings-300x300.webp\" alt=\"QFire LITE 4 PV firefighter switch for four PV strings without surge protection\" title=\"\"><\/td><\/tr><tr><td><img decoding=\"async\" style=\"width: 200px;\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-2-Strings-1-Ueberspannungsschutz-268x300.webp\" alt=\"QFire LITE 2 PV firefighter switch with Type 1+2 surge protection\" title=\"\"><\/td><td><img decoding=\"async\" style=\"width: 200px;\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-4-Strings-2-Ueberspannungsschutz-244x300.webp\" alt=\"QFire LITE 4 PV firefighter switch with two Type 1+2 surge protection devices\" title=\"\"><\/td><\/tr><\/tbody><\/table><\/figure>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:30%\">\n<h3 class=\"wp-block-heading has-text-align-center\" id=\"q-fire-lite-auf-einen-blick\">QFire LITE at a Glance<\/h3>\n\n\n\n<figure class=\"wp-block-table is-style-stripes ref-project-card\"><table><tbody><tr><td><strong>Application<\/strong><\/td><td>Standardised DC string isolation for applications with 2 or 4 PV strings per isolation point<\/td><\/tr><tr><td><strong>Function<\/strong><\/td><td>PV array isolation at the point of installation<\/td><\/tr><tr><td><strong>Disconnection<\/strong><\/td><td>Galvanic isolation according to IEC 60947-3<\/td><\/tr><tr><td><strong>Configuration<\/strong><\/td><td>2 PV strings or 4 PV strings<\/td><\/tr><tr><td><strong>MPP Trackers<\/strong><\/td><td>1 MPPT with LITE 2, 2 MPPTs with LITE 4<\/td><\/tr><tr><td><strong>System voltage<\/strong><\/td><td>Up to 1,500 V DC<\/td><\/tr><tr><td><strong>String current<\/strong><\/td><td>Up to 20 A Isc per string<\/td><\/tr><tr><td><strong>Connections<\/strong><\/td><td>St\u00e4ubli MC4-Evo 2, 4\u20136 mm\u00b2<\/td><\/tr><tr><td><strong>Device Supply<\/strong><\/td><td>230 V AC<\/td><\/tr><tr><td><strong>Automatic Reconnection<\/strong><\/td><td><br>Yes, when the AC supply is restored<\/td><\/tr><tr><td><strong>Degree of protection<\/strong><\/td><td><br><br>IP67<\/td><\/tr><tr><td><strong>Options<\/strong><\/td><td>Integrated Type 1+2 SPD, external emergency-off switch, key switch and volt-free status contact<\/td><\/tr><tr><td><strong>Installation location<\/strong><\/td><td>Sheltered outdoor location<\/td><\/tr><tr><td><strong>Manufacture<\/strong><\/td><td>Made in Germany<\/td><\/tr><\/tbody><\/table><\/figure>\n<\/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 is-layout-flow wp-block-column-is-layout-flow\">\n<h2 id=\"funktionsweise-und-abschaltlogik\" class=\"wp-block-heading\">Operating Principle and Shutdown Logic<\/h2>\n\n\n\n<h2 id=\"so-funktioniert-der-feuerwehrschalter-pv-q-fire-lite\" class=\"wp-block-heading\">How the QFire LITE PV Firefighter Switch Works<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">QFire LITE is installed in the individual DC string circuits between the PV array and the inverter. During normal system operation, the connected PV strings remain connected to the inverter. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the 230 V AC supply to QFire LITE is interrupted, the internal switching elements de-energise. The positive and negative conductors of every connected PV string are isolated. The DC cables between QFire LITE and the inverter are then isolated from the PV array and remain de-energised for the duration of the shutdown state.  <\/p>\n\n\n\n<h3 id=\"die-abschaltung-kann-ausgelost-werden-durch\" class=\"wp-block-heading\">The Isolation Can Be Triggered By:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>interruption of the 230 V AC supply,<\/li>\n\n\n\n<li>an external firefighter emergency-off switch,<\/li>\n\n\n\n<li>a key switch.<\/li>\n<\/ul>\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=\"der-q-fire-lite-trennt-die-strings-galvanisch-nach-iec-60947-3-die-zertifizierten-q-fire-ausfuhrungen-sind-fur-eine-bemessungsbetriebsspannung-von-1-500-v-dc-und-einen-bemessungsstrom-von-20-a-pro-string-gepruft\" class=\"wp-block-heading dc-card has-nv-light-bg-background-color has-background\"><strong>QFire LITE PV Firefighter Switch provides galvanic string isolation in accordance with IEC 60947-3. The QFire switching units have been tested at 1,500 V DC and up to 20 A Isc per string.<\/strong><\/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-columns alignfull has-neve-text-color-background-color has-background 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-bottom:var(--wp--preset--spacing--50)\">\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-neve-text-color-background-color has-text-color has-background has-link-color wp-elements-520a3203a14155eb4e8be508399b87b5 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 has-nv-site-bg-color has-text-color has-link-color wp-elements-b27950ab016c50d90faa633d66eb3f87 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<h3 id=\"funktion\" class=\"wp-block-heading has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-4b88c7b87f2dd1a0921e30a855008eed\" style=\"font-size:28px\">Operating Principle + Shutdown Logic<\/h3>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"wp-block-paragraph\" style=\"font-size:16px\">The QFire LITE PV Firefighter Switch provides double-pole, galvanic isolation of the positive and negative conductors of the connected PV strings when activated. Isolation can be triggered by:<\/p>\n\n\n\n<div id=\"wp-block-themeisle-blocks-icon-list-06b77a61\" class=\"wp-block-themeisle-blocks-icon-list\">\n<div id=\"wp-block-themeisle-blocks-icon-list-item-6adf424d\" class=\"wp-block-themeisle-blocks-icon-list-item\"><i class=\"fas fa-shield-alt wp-block-themeisle-blocks-icon-list-item-icon-custom\"><\/i><p class=\"wp-block-themeisle-blocks-icon-list-item-content-custom\"><strong>Interruption of the 230 V AC supply<\/strong><\/p><\/div>\n\n\n\n<div id=\"wp-block-themeisle-blocks-icon-list-item-48190b8b\" class=\"wp-block-themeisle-blocks-icon-list-item\"><i class=\"fas fa-shield-alt wp-block-themeisle-blocks-icon-list-item-icon-custom\"><\/i><p class=\"wp-block-themeisle-blocks-icon-list-item-content-custom\"><strong>A defined external control signal<\/strong><\/p><\/div>\n\n\n\n<div id=\"wp-block-themeisle-blocks-icon-list-item-953a992c\" class=\"wp-block-themeisle-blocks-icon-list-item\"><i class=\"fas fa-shield-alt wp-block-themeisle-blocks-icon-list-item-icon-custom\"><\/i><p class=\"wp-block-themeisle-blocks-icon-list-item-content-custom\"><strong>A firefighter emergency-off switch or key switch<\/strong><\/p><\/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-columns is-layout-flex wp-container-core-columns-is-layout-8d73e492 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--50);padding-bottom:var(--wp--preset--spacing--30);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<figure class=\"wp-block-image size-thumbnail q3-duotone\"><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_800px-150x150.webp\" alt=\"External Emergency Stop Switch QFire Firefighter Switch\" class=\"wp-image-1575\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_800px-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_800px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_800px-768x768.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/QFire_Not-Aus-Schalter_Aufputz_800px.webp 800w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/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)\">\n<figure class=\"wp-block-image size-thumbnail q3-duotone\"><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 Emergency Stop Switch QFire Firefighter Switch Key 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>\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)\">\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6a670ec952064&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6a670ec952064\" class=\"wp-block-image size-thumbnail q3-duotone wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/HME-SFT_HME_Handmelder_2_Wechsler_Kontakt_-230V_gelb_400px-150x150.webp\" alt=\"External Emergency Stop Switch QFire LITE Firefighter Switch Emergency Stop behind glass\" class=\"wp-image-1570\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/HME-SFT_HME_Handmelder_2_Wechsler_Kontakt_-230V_gelb_400px-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/HME-SFT_HME_Handmelder_2_Wechsler_Kontakt_-230V_gelb_400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/HME-SFT_HME_Handmelder_2_Wechsler_Kontakt_-230V_gelb_400px.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n<\/div>\n<\/div>\n\n\n\n<h3 id=\"nach-wiederkehr-der-ac-spannung-schaltet-q-fire-lite-automatisch-wieder-zu-sofern-keine-externe-abschaltbedingung-aktiv-ist\" class=\"wp-block-heading\" style=\"font-size:16px\">When the AC supply is restored, QFire LITE PV Firefighter Switch automatically reconnects the PV strings, provided that no external shutdown condition remains active.<\/h3>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch 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\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"400\" height=\"800\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Schaltschema-Feuerwehrschalter-QFire-LITE-weiss.webp\" alt=\"Operating diagram of the QFire LITE PV firefighter switch showing galvanic DC string isolation, 230 V AC shutdown control, emergency-off switch and automatic reconnection\" class=\"wp-image-1756\" style=\"width:300px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Schaltschema-Feuerwehrschalter-QFire-LITE-weiss.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Schaltschema-Feuerwehrschalter-QFire-LITE-weiss-150x300.webp 150w\" sizes=\"auto, (max-width: 400px) 100vw, 400px\" \/><\/figure>\n<\/div><\/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-columns has-neve-link-color-color has-text-color has-link-color wp-elements-4a44cee67026d1b6108e7f24215dea89 is-layout-flex wp-container-core-columns-is-layout-0fb72d45 wp-block-columns-is-layout-flex\" style=\"padding-top:0;padding-right:0;padding-bottom:0;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-4e455225240aa140693ce8c331221f52 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:0;padding-bottom:0;padding-left:0;flex-basis:90%\">\n<h2 id=\"standard\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-43760b3021cc48deb73a0814204c582b\" style=\"font-size:28px\">QFire LITE Variants for 2 or 4 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=\"has-neve-text-color-color has-text-color has-link-color wp-elements-a1426b70e3c087b09c0f522893b7da72 wp-block-paragraph\" style=\"font-size:16px\">QFire LITE is available in four clearly defined standard variants. Applications with 2 or 4 PV strings can therefore be selected, designed and installed quickly and efficiently. <\/p>\n\n\n\n<figure class=\"wp-block-table is-style-stripes ref-project-card\"><table class=\"has-neve-text-color-color has-text-color has-link-color\"><thead><tr><th class=\"has-text-align-center\" data-align=\"center\">Image<\/th><th class=\"has-text-align-center\" data-align=\"center\">Variant<\/th><th class=\"has-text-align-center\" data-align=\"center\">PV Strings<\/th><th class=\"has-text-align-center\" data-align=\"center\">MPP Trackers<\/th><th class=\"has-text-align-center\" data-align=\"center\">Surge protection<\/th><th class=\"has-text-align-center\" data-align=\"center\">Enclosure<\/th><\/tr><\/thead><tbody><tr><td class=\"has-text-align-center\" data-align=\"center\"><img decoding=\"async\" style=\"width: 150px;\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-2-Strings-300x300.webp\" alt=\"QFire LITE Firefighter Switch 2 Strings\" title=\"\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><strong>QFire LITE 2<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">2<\/td><td class=\"has-text-align-center\" data-align=\"center\">1<\/td><td class=\"has-text-align-center\" data-align=\"center\">None<\/td><td class=\"has-text-align-center\" data-align=\"center\">300 \u00d7 300 \u00d7 132 mm<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><img decoding=\"async\" style=\"width: 150px;\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-2-Strings-1-Ueberspannungsschutz-268x300.webp\" alt=\"QFire LITE Firefighter Switch 2 Strings 1 Surge Protection\" title=\"\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><strong>QFire LITE 2 + SPD<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">2<\/td><td class=\"has-text-align-center\" data-align=\"center\">1<\/td><td class=\"has-text-align-center\" data-align=\"center\">Type 1+2, 1,500 V DC<\/td><td class=\"has-text-align-center\" data-align=\"center\">300 \u00d7 400 \u00d7 132 mm<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><img decoding=\"async\" style=\"width: 150px;\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-2-Strings-300x300.webp\" alt=\"QFire LITE Firefighter Switch 4 Strings\" title=\"\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><strong>QFire LITE 4<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">4<\/td><td class=\"has-text-align-center\" data-align=\"center\">2<\/td><td class=\"has-text-align-center\" data-align=\"center\">None<\/td><td class=\"has-text-align-center\" data-align=\"center\">300 \u00d7 300 \u00d7 132 mm<\/td><\/tr><tr><td class=\"has-text-align-center\" data-align=\"center\"><img decoding=\"async\" style=\"width: 150px;\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-LITE-4-Strings-2-Ueberspannungsschutz-244x300.webp\" alt=\"QFire LITE Firefighter Switch 4 Strings 2 Surge Protection\" title=\"\"><\/td><td class=\"has-text-align-center\" data-align=\"center\"><strong>QFire LITE 4 + SPD<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">4<\/td><td class=\"has-text-align-center\" data-align=\"center\">2<\/td><td class=\"has-text-align-center\" data-align=\"center\">Type 1+2, 1,500 V DC<\/td><td class=\"has-text-align-center\" data-align=\"center\">300 \u00d7 400 \u00d7 132 mm<\/td><\/tr><\/tbody><\/table><\/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\"><span aria-hidden=\"true\" class=\"wp-block-cover__background 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 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-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--40);padding-right:var(--wp--preset--spacing--40);padding-bottom:var(--wp--preset--spacing--40);padding-left:var(--wp--preset--spacing--40)\">\n<h2 id=\"automatisches-wiederzuschalten\" class=\"wp-block-heading\">Automatic Reconnection<\/h2>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-9d3e8bdf wp-block-columns-is-layout-flex\" 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)\">\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)\">\n<h3 id=\"automatische-wiederinbetriebnahme-nach-netzwiederkehr\" class=\"wp-block-heading\" style=\"border-style:none;border-width:0px\">Automatic Return to Operation After Mains Restoration<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">If the AC supply fails, QFire LITE automatically enters a safe state and isolates the connected PV strings.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">As soon as the AC supply is restored and no external shutdown condition remains active, QFire LITE automatically reconnects the PV strings. No manual reset at the device is required following a routine mains interruption. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is particularly beneficial for:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>difficult-to-access roof areas,<\/li>\n\n\n\n<li>facade PV and high-rise buildings,<\/li>\n\n\n\n<li>systems with multiple distributed isolation boxes,<\/li>\n\n\n\n<li>installations subject to frequent short mains interruptions,<\/li>\n\n\n\n<li>commercial PV systems where unnecessary downtime must be avoided.<\/li>\n<\/ul>\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--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\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<h3 id=\"automatisch-sicher-abschalten-automatisch-wieder-strom-erzeugen\" class=\"wp-block-heading\"><strong>Automatically Isolate Safely \u2013 Automatically Resume Generation<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">QFire LITE combines galvanic DC string isolation with automatic reconnection when the AC supply is restored. The PV system therefore remains safely isolated during a mains failure without requiring an engineer to access the roof after every supply interruption. <\/p>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group dc-card has-background\" 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:#1c1c1c;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)\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-container-core-group-is-layout-67aea4fe wp-block-group-is-layout-constrained\">\n<h3 id=\"unterschied-zu-klassischen-feuerwehrschaltern-mit-unterspannungsausloser\" class=\"wp-block-heading\">Difference from Conventional Firefighter Switches with an Undervoltage Release<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">With conventional DC switch-disconnectors using an undervoltage release, loss of the AC supply mechanically trips the switch to the OFF position. After the mains supply has been restored, these designs remain in position 0 and must be reset locally. <\/p>\n\n\n\n<p class=\"wp-block-paragraph\">QFire LITE PV Firefighter Switch uses voltage-dependent, fail-safe isolation logic. If the control voltage is lost, the PV strings are isolated. When the supply returns and the shutdown circuit has been released, the system automatically reconnects the strings.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This eliminates the need for manual access to the isolation device following routine mains interruptions.<\/p>\n<\/div><\/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 style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-cover alignfull has-neve-text-color-color has-text-color has-link-color wp-elements-dab8de51f8e0fbc6e2e08da0fe0e507c\" 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-454 size-full\" alt=\"Technische Details\n\" 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-text-dark-bg-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 has-neve-link-color-color has-text-color has-link-color wp-elements-03b3c90124b7b76ba350d0c1f5b5d3ce is-layout-flex wp-container-core-columns-is-layout-0fb72d45 wp-block-columns-is-layout-flex\" style=\"padding-top:0;padding-right:0;padding-bottom:0;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-3c99a5982f6a29571aa18c07292a6620 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:100%\">\n<h2 id=\"technische-daten-normen-feuerwehrschalter-q-fire-lite\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-3a269fbf2dafb1239fb6aee46cb10c42\" style=\"font-size:28px\">QFire LITE PV Firefighter Switch Technical Data<\/h2>\n\n\n\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<figure class=\"wp-block-table is-style-stripes ref-project-card\"><table class=\"has-neve-text-color-color has-text-color has-link-color\"><thead><tr><th>Technisches Merkmal<\/th><th class=\"has-text-align-center\" data-align=\"center\">Design<\/th><\/tr><\/thead><tbody><tr><td><strong>Switching Method<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Galvanic isolation<\/td><\/tr><tr><td><strong>Disconnection<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Positive and negative conductors of each PV string<\/td><\/tr><tr><td><strong>Number of strings<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">2 or 4<\/td><\/tr><tr><td><strong><strong>MPP Trackers<\/strong><\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">1 with LITE 2, 2 with LITE 4<\/td><\/tr><tr><td><strong>System voltage<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Max. 1,500 V DC <\/td><\/tr><tr><td><strong><strong>String current<\/strong><\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Max. 20 A Isc per string <\/td><\/tr><tr><td><strong>Device Supply<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">230 V AC<\/td><\/tr><tr><td><strong><strong>Site-Provided Protection<\/strong><\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">B6 miniature circuit breaker<\/td><\/tr><tr><td><strong><strong>DC Connection<\/strong><\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">St\u00e4ubli MC4-Evo 2<\/td><\/tr><tr><td><strong>Conductor Cross-Section<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">4\u20136 mm\u00b2<\/td><\/tr><tr><td><strong>Enclosure Material<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Polycarbonate<\/td><\/tr><tr><td><strong>Degree of protection<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">IP67<\/td><\/tr><tr><td><strong>Impact Resistance<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">IK08<\/td><\/tr><tr><td><strong>Operating Temperature<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">\u221225 \u00b0C to +50 \u00b0C<\/td><\/tr><tr><td><strong>Installation location<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Sheltered outdoor location<\/td><\/tr><tr><td><strong>Automatic reconnection<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Yes<\/td><\/tr><tr><td><strong>Options<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Type 1+2 SPD, external emergency-off switch, key switch and volt-free status contact<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<div style=\"height:50px\" 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-8a7a34ae69e7c0c8c775ddb665e8047e wp-block-paragraph\">QFire has been tested in accordance with IEC 60947-3 at 1,500 V DC and 20 A per string. <br><br>The corresponding German adopted standard is <a href=\"https:\/\/www.dinmedia.de\/de\/norm\/din-en-iec-60947-3\/337479742\" data-type=\"link\" data-id=\"https:\/\/www.dinmedia.de\/de\/norm\/din-en-iec-60947-3\/337479742\" target=\"_blank\" rel=\"noopener\"><strong>DIN EN IEC 60947-3<\/strong>.<\/a><\/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\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/technic\/pv-firefighter-safety-switch\/\">Learn More About QFire Technology \u2192<\/a><\/div>\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=\"400\" height=\"400\" class=\"wp-block-cover__image-background wp-image-622 size-full\" alt=\"QFire Feuerwehrschalter Photovoltaik Variante LITE standardisierte wirtschaftliche Loesung\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Photovoltaik-Variante-LITE-standardisierte-wirtschaftliche-Loesung.webp 400w, 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\" 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-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-nv-text-dark-bg-color has-text-color has-link-color wp-elements-46d9e5bcbb1de0a6595889bae442325d\" id=\"unterschied\">Comparing QFire LITE and QFire BIG<\/h2>\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<figure class=\"wp-block-table aligncenter is-style-regular has-medium-font-size\"><table class=\"has-nv-site-bg-color has-text-color has-background has-link-color has-fixed-layout\" style=\"background-color:#004d997d;border-top-style:none;border-top-width:0px;border-right-style:none;border-right-width:0px;border-bottom-color:var(--wp--preset--color--nv-text-dark-bg);border-bottom-width:1px;border-left-style:none;border-left-width:0px\"><thead><tr><th>Feature<\/th><th class=\"has-text-align-center\" data-align=\"center\"><strong>QFire LITE<\/strong><\/th><th class=\"has-text-align-center\" data-align=\"center\"><strong>QFire BIG<\/strong><\/th><\/tr><\/thead><tbody><tr><td><strong>System Concept<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Standardised applications<\/td><td class=\"has-text-align-center\" data-align=\"center\">Project-specific and custom-engineered applications<\/td><\/tr><tr><td><strong>PV Strings per Enclosure<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">2 or 4<\/td><td class=\"has-text-align-center\" data-align=\"center\"><br>Up to 24<\/td><\/tr><tr><td><strong>System voltage<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Up to 1,500 V DC<\/td><td class=\"has-text-align-center\" data-align=\"center\">Up to 1,500 V DC<\/td><\/tr><tr><td><strong>String current<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Up to 20 A Isc<\/td><td class=\"has-text-align-center\" data-align=\"center\">Up to 20 A Isc<\/td><\/tr><tr><td><strong>Configuration<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Defined standard variants<\/td><td class=\"has-text-align-center\" data-align=\"center\">Freely configurable<\/td><\/tr><tr><td><strong>Surge protection<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Optionally integrated<\/td><td class=\"has-text-align-center\" data-align=\"center\">Can be integrated to project requirements<\/td><\/tr><tr><td><strong>PV Fuses<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Not included in the standard variants<\/td><td class=\"has-text-align-center\" data-align=\"center\">Optionally integrated<\/td><\/tr><tr><td><strong>Connection concept<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">MC4-Evo 2<\/td><td class=\"has-text-align-center\" data-align=\"center\">MC4-Evo 2, H4, Sunclix or terminal connections<\/td><\/tr><tr><td><strong>Cluster Control<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">No<\/td><td class=\"has-text-align-center\" data-align=\"center\">Yes<\/td><\/tr><tr><td><strong>Shutdown Control Method<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Standardised via the 230 V AC supply or an external switching device<\/td><td class=\"has-text-align-center\" data-align=\"center\">Project-specific via control box, emergency-off switch, key switch, fire alarm control panel or AC-side shutdown concept<\/td><\/tr><tr><td><strong>Typical application<\/strong><\/td><td class=\"has-text-align-center\" data-align=\"center\">Standardised isolation points with 2 or 4 PV strings, facade PV and repeatable system designs<\/td><td class=\"has-text-align-center\" data-align=\"center\">Commercial and industrial PV, logistics roofs and complex PV array configurations<\/td><\/tr><\/tbody><\/table><\/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 has-neve-link-color-color has-text-color has-link-color wp-elements-6ebeb26f1626eb596a456aa64a85d5ab is-layout-flex wp-container-core-columns-is-layout-439572a8 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--30);padding-right:0;padding-bottom:var(--wp--preset--spacing--30);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-8734c39bd72c5a4456120db8cda82655 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<h2 id=\"praxis\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-038c7715360893d6d858a6111a40a125\">PV System Safety Architecture<\/h2>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"praxisbeispiel-feuerwehrschalter-q-fire-lite-fur-fassaden-pv-an-hochhausern-hochhaus-pv-mit-stringweiser-abschaltung-pro-etage\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color wp-elements-6fbd87ffd3767464fd472fcee848b815\" style=\"font-size:20px\">Case Study: QFire LITE for Facade PV<br><\/h3>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-93af579e5e0182f1e929db79e24124ee wp-block-paragraph\" style=\"font-size:16px\"><strong>In fa\u00e7ade PV and high-rise projects, individual PV strings may enter the building floor by floor or fa\u00e7ade section by fa\u00e7ade section. QFire LITE provides clearly defined isolation points directly where the DC cables enter the building. <\/strong><\/p>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-b4e6213d25fff3b108ebd98da8c83714 wp-block-paragraph\" style=\"font-size:16px\">Multiple QFire LITE units can be isolated simultaneously via a centrally switched 230 V AC supply. When activated, each unit locally and galvanically isolates its assigned PV strings. This creates a transparent safety architecture with a clear allocation of strings to specific building sections or floors.  <\/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-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-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-color);border-left-width:1px;background-color:#f5f6f752;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<h3 id=\"losung-mit-q-fire-lite\" class=\"wp-block-heading has-neve-text-color-color has-text-color has-link-color has-medium-font-size wp-elements-012cb72cf97d420221d868ab4f0b727f\">Solution with QFire LITE<\/h3>\n\n\n\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-5b9f0c44f568474c9ad10fa9af76763e wp-block-paragraph\" style=\"font-size:16px\">A QFire LITE firefighter switch is installed on each floor directly at the entry point of the DC lines. In the event of triggering, galvanic isolation of the PV strings occurs immediately before entry into the building. <br><br>The QFire LITE units can be controlled centrally via a looped-through 230 V AC supply. If this supply is interrupted in the event of a fire \u2013 e.g., via a central firefighter emergency stop in the basement \u2013 all connected firefighter switches shut down simultaneously. <\/p>\n<\/div>\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-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-default\"><a class=\"wp-block-button__link has-border-color has-neve-text-color-border-color wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/firefighter-switch-for-facade-pv-high-rise\/\">View practical example: QFire LITE for facade PV \u2192<\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/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: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\">\n<figure data-wp-context=\"{&quot;imageId&quot;:&quot;6a670ec95b6d0&quot;}\" data-wp-interactive=\"core\/image\" data-wp-key=\"6a670ec95b6d0\" class=\"aligncenter size-large wp-lightbox-container\"><img loading=\"lazy\" decoding=\"async\" width=\"549\" height=\"1024\" data-wp-class--hide=\"state.isContentHidden\" data-wp-class--show=\"state.isContentVisible\" data-wp-init=\"callbacks.setButtonStyles\" data-wp-on--click=\"actions.showLightbox\" data-wp-on--load=\"callbacks.setButtonStyles\" data-wp-on--pointerdown=\"actions.preloadImage\" data-wp-on--pointerenter=\"actions.preloadImageWithDelay\" data-wp-on--pointerleave=\"actions.cancelPreload\" data-wp-on-window--resize=\"callbacks.setButtonStyles\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Hochhaus-PV-mit-stringweiser-Abschaltung-pro-Etage-inklusive-Ueberspannungsschutz-549x1024.webp\" alt=\"\" class=\"wp-image-1817\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Hochhaus-PV-mit-stringweiser-Abschaltung-pro-Etage-inklusive-Ueberspannungsschutz-549x1024.webp 549w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Hochhaus-PV-mit-stringweiser-Abschaltung-pro-Etage-inklusive-Ueberspannungsschutz-161x300.webp 161w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Hochhaus-PV-mit-stringweiser-Abschaltung-pro-Etage-inklusive-Ueberspannungsschutz-768x1433.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Hochhaus-PV-mit-stringweiser-Abschaltung-pro-Etage-inklusive-Ueberspannungsschutz-823x1536.webp 823w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Hochhaus-PV-mit-stringweiser-Abschaltung-pro-Etage-inklusive-Ueberspannungsschutz.webp 1072w\" sizes=\"auto, (max-width: 549px) 100vw, 549px\" \/><button\n\t\t\tclass=\"lightbox-trigger\"\n\t\t\ttype=\"button\"\n\t\t\taria-haspopup=\"dialog\"\n\t\t\tdata-wp-bind--aria-label=\"state.thisImage.triggerButtonAriaLabel\"\n\t\t\tdata-wp-init=\"callbacks.initTriggerButton\"\n\t\t\tdata-wp-on--click=\"actions.showLightbox\"\n\t\t\tdata-wp-style--right=\"state.thisImage.buttonRight\"\n\t\t\tdata-wp-style--top=\"state.thisImage.buttonTop\"\n\t\t>\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"12\" height=\"12\" fill=\"none\" viewBox=\"0 0 12 12\">\n\t\t\t\t<path fill=\"#fff\" d=\"M2 0a2 2 0 0 0-2 2v2h1.5V2a.5.5 0 0 1 .5-.5h2V0H2Zm2 10.5H2a.5.5 0 0 1-.5-.5V8H0v2a2 2 0 0 0 2 2h2v-1.5ZM8 12v-1.5h2a.5.5 0 0 0 .5-.5V8H12v2a2 2 0 0 1-2 2H8Zm2-12a2 2 0 0 1 2 2v2h-1.5V2a.5.5 0 0 0-.5-.5H8V0h2Z\" \/>\n\t\t\t<\/svg>\n\t\t<\/button><\/figure>\n<\/div><\/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-cover alignfull\" id=\"projektplanung\"><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<h3 class=\"wp-block-heading has-text-align-left alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-be08d2d27f93b870f1b002b1bba068f4\" id=\"vorteile-dieser-losung\" style=\"font-size:20px\">Advantages of this solution<\/h3>\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 has-neve-text-color-color has-text-color has-link-color wp-elements-4337bfb9d5153f6f8d15d8b13f8fea86 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 dc-card has-nv-light-bg-background-color has-background 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)\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-5d127027\" class=\"wp-block-themeisle-blocks-font-awesome-icons animated zoomIn delay-500ms\"><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<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" id=\"galvanische-dc-trennung-je-etage\" style=\"font-size:18px\"><strong>Galvanic DC isolation at the defined building entry point<\/strong><\/p>\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-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 style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-18e95918\" class=\"wp-block-themeisle-blocks-font-awesome-icons animated zoomIn delay-500ms\"><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<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\" id=\"zentrale-auslosung-dezentrale-abschaltung\" style=\"font-size:18px\"><strong>Central activation with distributed local isolation<\/strong><\/p>\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-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 style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-b2ebf0ca\" class=\"wp-block-themeisle-blocks-font-awesome-icons animated zoomIn delay-500ms\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container nan-padding\"><svg viewbox=\"0 0 1800 1800\"><path d=\"M1468.436,32.467v188.211c-98.748,15.249-174.595,100.822-174.595,203.777s75.847,188.521,174.595,203.777 v1139.302c0,17.453,14.146,31.608,31.607,31.608c17.454,0,31.609-14.155,31.609-31.608V628.232 c98.748-15.257,174.59-100.822,174.59-203.777s-75.842-188.529-174.59-203.777V32.467c0-17.454-14.155-31.608-31.609-31.608 C1482.581,0.858,1468.436,15.013,1468.436,32.467z M1643.029,424.455c0,67.979-47.703,124.986-111.377,139.423 c-10.179,2.302-20.744,3.563-31.609,3.563s-21.43-1.261-31.607-3.563c-63.684-14.438-111.378-71.444-111.378-139.423 c0-67.988,47.694-124.995,111.378-139.424c10.178-2.311,20.742-3.563,31.607-3.563s21.431,1.252,31.609,3.563 C1595.326,299.46,1643.029,356.467,1643.029,424.455z\"><\/path><path d=\"M331.574,1767.534V628.232c98.758-15.257,174.603-100.822,174.603-203.777s-75.845-188.529-174.603-203.777 V32.467c0-17.454-14.146-31.608-31.608-31.608c-17.454,0-31.608,14.155-31.608,31.608v188.211 C169.609,235.926,93.763,321.5,93.763,424.455s75.846,188.521,174.594,203.777v1139.302c0,17.453,14.155,31.608,31.608,31.608 C317.428,1799.143,331.574,1784.987,331.574,1767.534z M156.98,424.455c0-67.988,47.703-124.995,111.377-139.424 c10.178-2.311,20.752-3.563,31.608-3.563c10.865,0,21.431,1.252,31.608,3.563c63.684,14.429,111.387,71.436,111.387,139.424 c0,67.979-47.703,124.986-111.387,139.423c-10.178,2.302-20.743,3.563-31.608,3.563c-10.856,0-21.431-1.261-31.608-3.563 C204.683,549.441,156.98,492.434,156.98,424.455z\"><\/path><path d=\"M931.617,1767.534V1419.51c98.748-15.257,174.594-100.822,174.594-203.777s-75.846-188.529-174.594-203.777 V32.467c0-17.454-14.154-31.608-31.608-31.608c-17.462,0-31.608,14.155-31.608,31.608v979.488 c-98.757,15.248-174.603,100.822-174.603,203.777s75.846,188.521,174.603,203.777v348.024c0,17.453,14.146,31.608,31.608,31.608 C917.463,1799.143,931.617,1784.987,931.617,1767.534z M757.015,1215.732c0-67.986,47.703-124.995,111.386-139.424 c10.177-2.309,20.743-3.563,31.608-3.563c10.865,0,21.431,1.254,31.608,3.563c63.676,14.429,111.378,71.438,111.378,139.424 c0,67.979-47.702,124.986-111.378,139.424c-10.178,2.303-20.743,3.563-31.608,3.563c-10.865,0-21.431-1.26-31.608-3.563 C804.717,1340.719,757.015,1283.711,757.015,1215.732z\"><\/path><\/svg><\/span><\/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-center wp-block-paragraph\" id=\"standardisierte-skalierbare-losung\" style=\"font-size:18px\"><strong>A standardised solution for repeatable isolation points<\/strong><\/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<div class=\"wp-block-cover alignwide is-light has-neve-text-color-color has-text-color has-link-color wp-elements-ac7e840d46a25d47e73c54a441f637f8\" style=\"padding-top:var(--wp--preset--spacing--50);padding-right:var(--wp--preset--spacing--20);padding-bottom:var(--wp--preset--spacing--50);padding-left:var(--wp--preset--spacing--20)\"><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-text-dark-bg-background-color has-background-dim-0 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<h2 id=\"haufige-fragen-zum-feuerwehrschalter-q-fire-lite\" class=\"wp-block-heading\">Frequently Asked Questions About the QFire LITE PV Firefighter Switch<\/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 has-dark-content-bg has-dark-title-bg has-light-active-title-bg ticss-8e791480 is-style-default\">\n<details class=\"wp-block-themeisle-blocks-accordion-item\"><summary class=\"wp-block-themeisle-blocks-accordion-item__title\"><div>What Is the QFire LITE PV Firefighter Switch?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-6811775343e172b7709cdd7f004827df wp-block-paragraph\" style=\"font-size:18px\">QFire LITE is a compact isolation device for PV systems with 2 or 4 PV strings. When activated, it galvanically isolates the positive and negative conductors of the connected strings between the PV array and the inverter. <\/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 Happens in the Event of a Mains Failure?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-ef3535f14176a3dffdfa3e7c03ea8709 wp-block-paragraph\" style=\"font-size:18px\">If the 230 V AC supply fails, QFire LITE automatically enters the safe state. The PV strings are isolated from the inverter at the installation point of the device. <\/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>Does QFire LITE Reconnect Automatically After a Mains Failure?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-7d6e3158e9986ff93226f077147b5cbd wp-block-paragraph\" style=\"font-size:18px\">Yes. As soon as the AC supply has been restored and the external shutdown circuit has been released, QFire LITE automatically reconnects the connected PV strings. <\/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 PV Strings Can QFire LITE Switch?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-c0dee102fac0e41391dd1d0f94695f24 wp-block-paragraph\" style=\"font-size:18px\">QFire LITE is available for 2 PV strings with one MPP tracker or for 4 PV strings with two MPP trackers.<\/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 Information Is Required for Technical Sizing?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-e04b2824048ee9dcf884895e5ee1752b wp-block-paragraph\" style=\"font-size:18px\">For a fast and reliable design, the string plan, inverter type, number of MPPT, string allocation per MPPT and module data are particularly helpful. In addition, information on short-circuit current (Isc), the desired protection concept and the connection technology is required. <\/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 Does QFire LITE Differ from Eaton SOL30 and SOL30x-Safety?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-b892267d8055a69bb5c88c93ffae9725 wp-block-paragraph\" style=\"font-size:18px\">Eaton SOL30 and SOL30x-Safety use an integrated undervoltage release and a mechanical switch that returns to the 0\/OFF position. QFire LITE also isolates the connected PV strings automatically if the AC supply fails, but reconnects them automatically when the supply is restored, provided no external shutdown condition remains active.<br>QFire LITE is also designed for system voltages up to 1,500 V DC, whereas Eaton specifies up to 1,000 V DC for SOL30 and SOL30x-Safety.  <\/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>When Is QFire BIG Required Instead of QFire LITE?<\/div><\/summary><div class=\"wp-block-themeisle-blocks-accordion-item__content\">\n<p class=\"has-neve-text-color-color has-text-color has-link-color wp-elements-7c68a217c2e6f96d1eed061808dd6b57 wp-block-paragraph\" style=\"font-size:18px\">QFire BIG is intended for systems with more than four PV strings, custom connection concepts, cluster control, integrated PV string fuses or complex AC- and DC-side shutdown requirements.<\/p>\n<\/div><\/details>\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-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-454 size-full\" alt=\"Technische Details\n\" 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-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<h2 class=\"wp-block-heading alignwide has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-f0b3e11cb9aa2c71b46fa7a59d159f7d\" id=\"projektanfrage-feuerwehrschalter-q-fire-lite\" style=\"font-size:28px\">QFire LITE Project Enquiry<\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-6bc4591efad8e9c6f09376f09bab267c is-layout-flex wp-container-core-columns-is-layout-0fb72d45 wp-block-columns-is-layout-flex\" style=\"padding-top:0;padding-right:0;padding-bottom:0;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-7174ac1fabc8322d4497b97351c16842 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=\"wp-block-paragraph\" style=\"font-size:16px\"><strong>Would you like to design the QFire LITE system for a specific project, have technical details checked, or select the appropriate system configuration for your photovoltaic system?<\/strong><br><br><br>Using the inquiry form below, we collect all relevant project data in a structured and transparent manner.<\/p>\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=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-297df2a348be3b90bcb3628c48036cad wp-block-paragraph\" style=\"font-size:16px\"><em>You are welcome to send wiring diagrams, string plans, or other technical documents directly. Based on this, we will check the technical framework, design the QFire LITE system to suit your project, and coordinate the components specifically.<br>Should any questions arise, we will contact you. Otherwise, you will receive a project-specific offer directly.  <\/em><\/p>\n\n\n\n<div class=\"wp-block-buttons alignwide is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-67a17663 wp-block-buttons-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-button has-custom-width wp-block-button__width-50 is-style-secondary\"><a class=\"wp-block-button__link has-text-align-center has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/qfire-pv-firefighter-switch\/\" style=\"border-width:1px\">Start project inquiry \u2192<\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-group alignfull has-nv-c-2-background-color has-background\" id=\"produkte\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;padding-right: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-e59bffbc wp-block-group-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=\"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--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-top animated fadeIn q3-product-card has-large-font-size 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)\">\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-1733 size-full\" alt=\"Anfrage\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage-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-80 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:10px\" 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-89477cfdc06671892976a3c9ee8f106d\" id=\"projektanfrage-feuerwehrschalter\" style=\"font-size:20px\">Project Inquiry Firefighter Switch<\/h3>\n\n\n<div class=\"wp-block-image wp-duotone-unset-1\">\n<figure class=\"aligncenter size-thumbnail has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage-150x150.webp\" alt=\"Inquiry\" class=\"wp-image-1733\" style=\"border-style:none;border-width:0px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Anfrage.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-fc3b1fb8c4b88f4e1df53ef9ce558804 wp-block-paragraph\" style=\"font-size:16px\">Project-specific inquiry for QFire system design. Component selection and quotation preparation. <\/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 q3-card-link\"><a class=\"wp-block-button__link has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/qfire-pv-firefighter-switch\/\">Start QFire Firefighter Switch Project Inquiry \u2192<\/a><\/div>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top animated fadeIn q3-product-card has-large-font-size 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)\">\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-1732 size-full\" alt=\"PDF\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF.webp 400w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF-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-80 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:10px\" 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-68a7dacdd698c2ca6af8cba304cd345d\" id=\"technischer-download-feuerwehrschalter\" style=\"font-size:20px\">Firefighter Switch Technical Download<\/h3>\n\n\n<div class=\"wp-block-image wp-duotone-unset-2\">\n<figure class=\"aligncenter size-thumbnail has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF-150x150.webp\" alt=\"PDF icon for QFire firefighter switch technical documentation\" class=\"wp-image-1732\" style=\"border-style:none;border-width:0px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/PDF.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-fdd25014d2944de9dc0556ebe68fb557 wp-block-paragraph\" style=\"font-size:16px\">Data sheets, certificates, and technical documentation for QFire BIG and LITE, control boxes, switch boxes, and accessories.<\/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 q3-card-link\"><a class=\"wp-block-button__link has-medium-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 Documentation for Firefighter Switch \u2192<\/a><\/div>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top animated fadeIn q3-product-card has-large-font-size 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)\">\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=\"1600\" height=\"1600\" class=\"wp-block-cover__image-background wp-image-897 size-full\" alt=\"Wann ist bei einer PV Anlage ein Feuerwehrschalter Pflicht?\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend.png\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend.png 1600w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-300x300.png 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-1024x1024.png 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-150x150.png 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-768x768.png 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-1536x1536.png 1536w\" sizes=\"auto, (max-width: 1600px) 100vw, 1600px\" \/><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-constrained wp-container-core-cover-is-layout-0255ba1e wp-block-cover-is-layout-constrained\">\n<div style=\"height:10px\" 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-216adf971cc1405ea4e0356ac367ce4d\" id=\"funktionsweise-technik-q-fire\" style=\"font-size:20px\">Functionality &amp; Technology QFire<\/h3>\n\n\n<div class=\"wp-block-image wp-duotone-unset-3\">\n<figure class=\"aligncenter size-thumbnail has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/neu.q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-150x150.png\" alt=\"When is a firefighter switch mandatory for a PV system?\" class=\"wp-image-897\" style=\"border-style:none;border-width:0px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-150x150.png 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-300x300.png 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-1024x1024.png 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-768x768.png 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend-1536x1536.png 1536w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Wann-FWS-verpflichtend.png 1600w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-fd0acb6edb652781c53480b0246f74ea wp-block-paragraph\" style=\"font-size:16px\">Technical fundamentals of DC-side disconnection, system design, triggering methods, galvanic isolation, and standards-compliant implementation.<\/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 q3-card-link\"><a class=\"wp-block-button__link has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/technic\/pv-firefighter-safety-switch\/\">Functionality + Technology Firefighter Switch \u2192<\/a><\/div>\n<\/div>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-top animated fadeIn q3-product-card has-large-font-size 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)\">\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-1731 size-full\" alt=\"FAQ Feuerwehrschalter\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter.webp\" data-object-fit=\"cover\" 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\" \/><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-constrained wp-container-core-cover-is-layout-0255ba1e wp-block-cover-is-layout-constrained\">\n<div style=\"height:10px\" 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-9219ac5db6648addf7df52005be5f549\" id=\"faq-zum-thema-feuerwehrschalter\" style=\"font-size:20px\">FAQ on Firefighter Switches<\/h3>\n\n\n<div class=\"wp-block-image wp-duotone-unset-4\">\n<figure class=\"aligncenter size-thumbnail has-custom-border\"><img loading=\"lazy\" decoding=\"async\" width=\"150\" height=\"150\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter-150x150.webp\" alt=\"Firefighter Switch FAQ\" class=\"wp-image-1731\" style=\"border-style:none;border-width:0px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/FAQ-Feuerwehrschalter-150x150.webp 150w, 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.webp 400w\" sizes=\"auto, (max-width: 150px) 100vw, 150px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-34414513f6ce6f0b4643668b8004ff01 wp-block-paragraph\" style=\"font-size:16px\">Answers to frequently asked questions about application, standards, triggering concepts, mandatory requirements, and operation of firefighter switches in PV 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 q3-card-link\"><a class=\"wp-block-button__link has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/knowledge\/faq-pv-firefighter-switch\/\">FAQ on Firefighter Switches \u2192<\/a><\/div>\n<\/div>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div><\/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","protected":false},"excerpt":{"rendered":"<p>QFire LITE PV Firefighter Switch: Compact Remote DC Isolation for Standardised PV Applications QFire LITE is a compact PV firefighter safety switch for standardised applications with 2 or 4 PV strings. It is installed close to the PV array or at the point where the DC cables enter the building and galvanically isolates the positive&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":7509,"parent":7284,"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-7507","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\/7507","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=7507"}],"version-history":[{"count":18,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7507\/revisions"}],"predecessor-version":[{"id":9578,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7507\/revisions\/9578"}],"up":[{"embeddable":true,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/7284"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/media\/7509"}],"wp:attachment":[{"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/media?parent=7507"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}