{"id":11564,"date":"2026-10-26T15:08:56","date_gmt":"2026-10-26T14:08:56","guid":{"rendered":"https:\/\/q3-energie.de\/products\/pv-abschaltung-mit-speicher-und-ersatzstrom-qfire-ac-dc\/"},"modified":"2026-10-28T13:04:32","modified_gmt":"2026-10-28T12:04:32","slug":"pv-shutdown-battery-storage-backup-power","status":"publish","type":"page","link":"https:\/\/q3-energie.de\/en\/products\/pv-shutdown-battery-storage-backup-power\/","title":{"rendered":"PV Shutdown with Battery Storage &#038; Backup Power | QFire AC\/DC"},"content":{"rendered":"\n<div class=\"wp-block-cover alignfull\" style=\"min-height:603px;aspect-ratio:unset;\"><img decoding=\"async\" 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.webp\" data-object-fit=\"cover\" title=\"\"><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=\"q-fire-ac-dc-feuerwehrschalter-fur-pv-anlagen-mit-speicher-und-ersatzstrom\"><strong>QFire AC\/DC \u2013 Firefighter Safety Switch for PV Systems with Hybrid Inverters, Battery Storage and Backup Power<\/strong><\/h1>\n\n\n\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-left has-nv-text-dark-bg-color has-text-color\" id=\"pv-generatorfreischaltung-und-ac-seitige-sicherheitsabschaltung-in-einem-abgestimmten-system\" style=\"font-size:18px\"><strong><strong>One shutdown. All energy sources under control. For PV systems with battery storage and backup power.<\/strong><\/strong><\/h3>\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 style=\"--wp--block-button--width: 50;\" class=\"wp-block-button is-style-primary animated fadeInLeft has-custom-width wp-block-button__width wp-block-button__width-50\"><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=\"#PV-Shutdown-with-Battery-Storage-and-Backup-Power\" 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)\">QFire AC\/DC operating principle \u2192<\/a><\/div>\n\n\n\n<div style=\"--wp--block-button--width: 50;\" class=\"wp-block-button is-style-secondary animated fadeInLeft delay-100ms has-custom-width wp-block-button__width wp-block-button__width-50\"><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=\"#Three-Components.-One-Coordinated-Shutdown-Concept\" 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)\">System components at a glance \u2192<\/a><\/div>\n\n\n\n<div style=\"--wp--block-button--width: 50;\" class=\"wp-block-button is-style-secondary animated fadeInLeft delay-200ms has-custom-width wp-block-button__width wp-block-button__width-50\"><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=\"#Why-PV-Shutdown-and-Backup-Power-Must-Be-Considered-Together\" 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)\">QFire AC\/DC shutdown concept \u2192<\/a><\/div>\n\n\n\n<div style=\"--wp--block-button--width: 50;\" class=\"wp-block-button is-style-primary animated fadeInLeft delay-500ms has-custom-width wp-block-button__width wp-block-button__width-50\"><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=\"#QFire-AC-DC-\u2013-Because-Safety-Does-Not-End-at-the-Grid-Connection\" 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)\">Enquire about QFire AC\/DC \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\"><div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"800\" height=\"800\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten.webp\" alt=\"PV shutdown with battery storage, PV shutdown with backup power, coordinated DC and AC shutdown, hybrid inverter safety shutdown, firefighter safety switch battery storage\" class=\"wp-image-11430\" style=\"width:500px;height:auto\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten.webp 800w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-768x768.webp 768w\" sizes=\"auto, (max-width: 800px) 100vw, 800px\" \/><\/figure>\n<\/div><\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-rank-math-toc-block q3-toc\" id=\"rank-math-toc\"><h2>On this page<\/h2><nav><ul><li class=\"\"><a href=\"#pv-generatorfreischaltung-und-ac-seitige-sicherheitsabschaltung-in-einem-abgestimmten-system\">PV Shutdown with Battery Storage and Backup Power: When Grid Disconnection Is Not Enough<\/a><\/li><li class=\"\"><a href=\"#q-fire-ac-dc-dc-und-ac-abschaltung-in-einem-sicherheitskonzept\">QFire AC\/DC \u2013 DC and AC Isolation within One Safety Concept<\/a><\/li><li class=\"\"><a href=\"#netzausfall-und-sicherheitsauslosung-unterscheiden\">\nDistinguishing Grid Failure from Safety Activation<\/a><\/li><li class=\"\"><a href=\"#dc-ruckspeisepfade-berucksichtigen\">\nAccounting for DC Backfeed Paths<\/a><\/li><li class=\"\"><a href=\"#auslosung-und-status-zentral-zusammenfuhren\">\nCentralising Activation and Status Indication<\/a><\/li><li class=\"\"><a href=\"#planung-und-umsetzung-vereinfachen\">\nSimplifying Design and Installation<\/a><\/li><li class=\"\"><a href=\"#sicherheitsauslosung-hat-vorrang-vor-ersatzstrom\">Safety Activation Takes Priority over Backup Supply<\/a><\/li><\/ul><\/nav><\/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-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:60%\">\n<p class=\"wp-block-paragraph\" id=\"das-haus-ist-vom-netz-aber-ist-es-wirklich-abgeschaltet-moderne-batteriespeicher-konnen-das-gebaude-weiterhin-versorgen-q-fire-ac-dc-bringt-pv-dc-abschaltung-und-ac-quellentrennung-zusammen\" style=\"font-size:16px\"><strong>The building is disconnected from the grid \u2013 but is its power supply actually isolated? Modern battery storage systems can continue to supply the building. QFire AC\/DC combines PV DC isolation with AC source disconnection.<\/strong><\/p>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 id=\"PV-Shutdown-with-Battery-Storage-and-Backup-Power\" class=\"wp-block-heading\">PV Shutdown with Battery Storage and Backup Power: When Grid Disconnection Is Not Enough<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Conventional PV shutdown concepts often focus on <a href=\"https:\/\/feuerwehrschalter.de\" data-type=\"link\" data-id=\"https:\/\/feuerwehrschalter.de\" target=\"_blank\" rel=\"noopener\">DC isolation <\/a>on the PV array side. Systems with battery storage and backup capability introduce an additional supply path.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When the public grid is disconnected, a suitable hybrid inverter can switch to backup operation. The building circuits supplied from its backup output therefore remain energised.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A more comprehensive shutdown concept must address both:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>DC side: Isolation of the PV strings at defined switching points close to the PV array.<\/li>\n\n\n\n<li><strong>AC side: Disconnection of the connected building circuits from both the public grid and the EPS\/backup output.<\/strong><\/li>\n<\/ul>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h3 id=\"q-fire-ac-dc-dc-und-ac-abschaltung-in-einem-sicherheitskonzept\" class=\"wp-block-heading\">QFire AC\/DC \u2013 DC and AC Isolation within One Safety Concept<\/h3>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"alignleft size-full is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"473\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire_AC-DC_Operating_Principle.webp\" alt=\"\" class=\"wp-image-11578\" style=\"width:auto;height:300px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire_AC-DC_Operating_Principle.webp 1200w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire_AC-DC_Operating_Principle-300x118.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire_AC-DC_Operating_Principle-1024x404.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire_AC-DC_Operating_Principle-768x303.webp 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n<\/div><\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:40%\">\n<h3 class=\"wp-block-heading has-text-align-center\" id=\"q-fire-big-auf-einen-blick\">QFire AC\/DC 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>PV systems with battery storage and backup power<\/td><\/tr><tr><td><strong>Switching principle<\/strong><\/td><td>Galvanic isolation of PV strings; two-pole isolation of positive and negative conductors<\/td><\/tr><tr><td><strong>Maximum DC system voltage<\/strong><\/td><td>Up to 1,500 V DC<\/td><\/tr><tr><td><strong>Maximum string short-circuit current<\/strong><\/td><td>20 A Isc per string <\/td><\/tr><tr><td><strong>Number of strings<\/strong><\/td><td>Up to 24 strings per <a href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/#schaltbox\" data-type=\"link\" data-id=\"https:\/\/q3-energie.de\/produkte\/feuerwehrschalter-qfire-big\/#schaltbox\">QFire BIG switch box<\/a>; larger systems use multiple boxes in a modular arrangement<\/td><\/tr><tr><td><strong>Connections<\/strong><\/td><td>St\u00e4ubli MC4-Evo 2; terminal connections available as an option<\/td><\/tr><tr><td><strong>Enclosure \/ degree of protection<\/strong><\/td><td>Up to 16 strings: polycarbonate, IP66\/67; 18\u201324 strings: sheet steel, IP66; depending on configuration<\/td><\/tr><tr><td><strong>Installation location<\/strong><\/td><td>Sheltered outdoor area<\/td><\/tr><tr><td><strong>Options<\/strong><\/td><td>Type 1+2 DC surge protection, fuses, status indication and further configuration-dependent options<\/td><\/tr><tr><td><strong>DC standards reference<\/strong><\/td><td>IEC 60947-3; application reference: VDE-AR-E 2100-712<\/td><\/tr><tr><td><strong>AC disconnection<\/strong><\/td><td>Isolation of the connected building circuits from the grid and EPS supply<\/td><\/tr><tr><td><strong>Safety activation<\/strong><\/td><td>Common activation via the QFire control system<\/td><\/tr><tr><td><strong>ATS changeover<\/strong><\/td><td>Four-pole, L1\/L2\/L3\/N<\/td><\/tr><tr><td><strong>ATS rated current<\/strong><\/td><td>63 &#8211; 630 A<\/td><\/tr><tr><td><strong>System design<\/strong><\/td><td>Modular, project-specific<\/td><\/tr><tr><td><strong>Integration<\/strong><\/td><td>External initiating device or signal<\/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<h2 id=\"Why-PV-Shutdown-and-Backup-Power-Must-Be-Considered-Together\" class=\"wp-block-heading\">Why PV Shutdown and Backup Power Must Be Considered Together<\/h2>\n\n\n\n<div class=\"wp-block-columns has-neve-link-color-color has-text-color has-background has-link-color wp-elements-1 is-layout-flex wp-container-core-columns-is-layout-5e6aac66 wp-block-columns-is-layout-flex\" style=\"background-color:#ffffff8c;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-vertically-aligned-stretch dc-card has-border-color has-nv-light-bg-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-width:1px;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);flex-basis:33.34%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-99531212\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container\"><a href=\"https:\/\/feuerwehrschalter.de\" target=\"_self\" rel=\"noopener noreferrer\"><i class=\"fas fa-exchange-alt\"><\/i><\/a><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-2\" id=\"netzausfall-und-sicherheitsauslosung-unterscheiden\" style=\"font-size:20px\"><br><strong>Distinguishing Grid Failure from Safety Activation<\/strong><\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-3 wp-block-paragraph\" style=\"font-size:16px\"><br>Automatic backup supply is desirable during a grid failure. During a deliberate safety shutdown, however, it must not continue to supply the connected building circuits.<\/p>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:var(--nv-light-bg);border-width:1px;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);flex-basis:33.34%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-f8b5a60a\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container\"><a href=\"https:\/\/q3-energie.de\/en\/company\/about-q3-energie-q3-the-box-makers\/\" target=\"_self\" rel=\"noopener noreferrer\"><i class=\"fas fa-reply\"><\/i><\/a><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-4\" id=\"dc-ruckspeisepfade-berucksichtigen\" style=\"font-size:20px\"><br><strong>Accounting for DC Backfeed Paths<\/strong><\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-5 wp-block-paragraph\" style=\"font-size:16px\"><br>An inverter being switched off or disconnected from the grid does not automatically mean that all connected DC circuits are de-energised. Potential backfeed from the inverter or battery storage system must be assessed against the actual system architecture.<\/p>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:var(--nv-light-bg);border-width:1px;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);flex-basis:33.33%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-ecd02c60\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container\"><a href=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/\" target=\"_self\" rel=\"noopener noreferrer\"><i class=\"fas fa-sliders-h\"><\/i><\/a><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-6\" id=\"auslosung-und-status-zentral-zusammenfuhren\" style=\"font-size:20px\"><br>Centralising Activation and Status Indication<\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-7 wp-block-paragraph\" style=\"font-size:16px\"><br>A clear, centrally accessible operating and status indication arrangement supports emergency responders and those responsible for the building when initiating a deliberate safety shutdown.<\/p>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:var(--nv-light-bg);border-width:1px;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);flex-basis:33.33%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<div id=\"wp-block-themeisle-blocks-font-awesome-icons-69d3dc94\" class=\"wp-block-themeisle-blocks-font-awesome-icons\"><span class=\"wp-block-themeisle-blocks-font-awesome-icons-container\"><a href=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/\" target=\"_self\" rel=\"noopener noreferrer\"><i class=\"fas fa-clipboard-list\"><\/i><\/a><\/span><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-8\" id=\"planung-und-umsetzung-vereinfachen\" style=\"font-size:20px\"><br>Simplifying Design and Installation<\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-9 wp-block-paragraph\" style=\"font-size:16px\"><br>Standardised interfaces and documented operating sequences help installers implement a coordinated shutdown concept and reduce the need for bespoke control logic between separate components.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-cover alignfull\"><img loading=\"lazy\" decoding=\"async\" width=\"1058\" height=\"800\" class=\"wp-block-cover__image-background wp-image-812 size-full\" alt=\"Cluster Steuerbox f\u00fcr mehrere Generatorfl\u00e4chen\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen.webp 1058w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-300x227.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-1024x774.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Cluster-Steuerbox-fuer-mehrere-Generatorflaechen-768x581.webp 768w\" sizes=\"auto, (max-width: 1058px) 100vw, 1058px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-10 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-center has-nv-site-bg-color has-text-color has-link-color wp-elements-11 is-layout-flow wp-block-column-is-layout-flow\" style=\"padding-top:0;padding-right:0;padding-bottom:0;padding-left:0;flex-basis:100%\">\n<div style=\"height:30px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 id=\"q-fire-ac-dc-eine-auslosung-zwei-abgestimmte-abschaltfunktionen\" class=\"wp-block-heading\">One Trigger. Two Coordinated Shutdown Functions.<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The system combines project-specific QFire PV array isolation with a Q3 ATS box for grid and backup supply.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-link-color wp-elements-12 is-layout-flex wp-container-core-columns-is-layout-0e642418 wp-block-columns-is-layout-flex\" style=\"padding-top:var(--wp--preset--spacing--40);padding-right:0;padding-bottom:var(--wp--preset--spacing--40);padding-left:0\">\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color has-nv-site-bg-color has-text-color has-link-color wp-elements-13 is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:#363636;border-width:1px;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);flex-basis:100%\">\n<h3 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-14\" id=\"1-zentrale-sicherheitsauslosung\" style=\"border-style:none;border-width:0px;font-size:24px\">1. Central Safety Activation<\/h3>\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\">Shutdown is initiated via the designated QFire safety activation interface, for example by an external firefighter\/emergency-off push-button or a suitable signal from the fire detection and alarm system.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\">Control of the DC switch boxes and the AC disconnection function is coordinated within the common system concept.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color has-nv-site-bg-color has-text-color has-link-color wp-elements-15 is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:#363636;border-width:1px;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);flex-basis:100%\">\n<h3 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-16\" id=\"2-galvanische-dc-stringtrennung\" style=\"border-style:none;border-width:0px;font-size:24px\">2. Galvanic DC String Isolation<\/h3>\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\">The QFire switch boxes provide two-pole galvanic isolation of the connected PV strings, disconnecting both positive and negative conductors in accordance with IEC 60947-3.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\">Switch box locations are selected to suit the system layout, for example close to the PV array or where the DC cables enter the building.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\">Isolation interrupts the supply from the PV strings to the downstream cable sections.<\/p>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color has-nv-site-bg-color has-text-color has-link-color wp-elements-17 is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:#363636;border-width:1px;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);flex-basis:100%\">\n<h3 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-18\" id=\"3-ac-abschaltung-uber-die-q-3-ats-box\" style=\"border-style:none;border-width:0px;font-size:24px\">3. AC Disconnection from the Grid and EPS Supply<\/h3>\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\">During normal operation, the Q3 ATS box automatically transfers the building\u2019s three-phase supply between the public grid and the EPS\/backup output of a suitable inverter.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\">Within the QFire AC\/DC system, the ATS is additionally incorporated into the safety shutdown function. On shutdown, the building circuits connected through the ATS are disconnected from both AC supply paths.<\/p>\n\n\n\n<p class=\"has-text-align-center wp-block-paragraph\">This prevents automatic transfer to backup power from continuing to supply these circuits after safety shutdown has been initiated.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column dc-card has-background is-layout-flow wp-block-column-is-layout-flow\" style=\"border-top-left-radius:8px;border-top-right-radius:8px;border-bottom-left-radius:8px;border-bottom-right-radius:8px;border-left-width:1px;background-color:#262626;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 class=\"wp-block-heading alignwide\" id=\"sicherheitsauslosung-hat-vorrang-vor-ersatzstrom\">Safety Activation Takes Priority over Backup Supply<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">During a normal grid failure, automatic transfer to backup power remains available as intended. Deliberate safety activation, however, takes priority over automatic supply transfer.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The safety concept provides for an interlock to prevent automatic reconnection. The conditions for reset and re-enabling will be defined as part of system development.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:100px\" 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\"><img loading=\"lazy\" decoding=\"async\" width=\"1920\" height=\"800\" class=\"wp-block-cover__image-background wp-image-454 size-full\" alt=\"\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp\" data-object-fit=\"cover\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px.webp 1920w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-300x125.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1024x427.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-768x320.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/Background_1920px-1536x640.webp 1536w\" sizes=\"auto, (max-width: 1920px) 100vw, 1920px\" \/><span aria-hidden=\"true\" class=\"wp-block-cover__background has-nv-site-bg-background-color has-background-dim-90 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-flow wp-block-cover-is-layout-flow\">\n<h2 class=\"wp-block-heading alignwide has-neve-text-color-color has-text-color has-link-color wp-elements-19\" id=\"Three-Components.-One-Coordinated-Shutdown-Concept\">Three Components. One Coordinated Shutdown Concept. <\/h2>\n\n\n\n<div class=\"wp-block-columns alignwide has-neve-link-color-color has-text-color has-background has-link-color wp-elements-20 is-layout-flex wp-container-core-columns-is-layout-5e6aac66 wp-block-columns-is-layout-flex\" style=\"background-color:#ffffff8c;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-vertically-aligned-stretch dc-card has-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:var(--nv-light-bg);border-width:1px;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);flex-basis:33.34%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<figure class=\"wp-block-image size-medium wp-container-content-b0827016\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"200\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-300x200.webp\" alt=\"QFire Firefighter Switch Control Box\" class=\"wp-image-800\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-300x200.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox-768x512.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/01\/QFire-Feuerwehrschalter-Steuerbox.webp 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n\n\n\n<div style=\"height:86px\" aria-hidden=\"true\" class=\"wp-block-spacer wp-container-content-d4696822\"><\/div>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-21\" id=\"q-fire-steuerbox-zentrale-sicherheitsauslosung\" style=\"font-size:20px\"><br><strong>QFire Control Box \u2013 Central Safety Activation<\/strong><\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-22 wp-block-paragraph\" style=\"font-size:16px\"><br>The QFire control box provides the central interface for initiating shutdown and controlling the connected DC switch boxes. For QFire AC\/DC, the AC safety disconnection function is integrated into the common control concept.<\/p>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color has-nv-light-bg-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-width:1px;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);flex-basis:33.34%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<figure class=\"wp-block-image size-medium wp-container-content-b0827016\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-BIG-Schaltbox-mit-24-Strings-und-Ueberspannungsschutz-400px-300x300.webp\" alt=\"QFire BIG Firefighter Switch Box with 24 Strings and Surge Protection\" class=\"wp-image-1691\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-BIG-Schaltbox-mit-24-Strings-und-Ueberspannungsschutz-400px-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-BIG-Schaltbox-mit-24-Strings-und-Ueberspannungsschutz-400px-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/02\/Feuerwehrschalter-QFire-BIG-Schaltbox-mit-24-Strings-und-Ueberspannungsschutz-400px.webp 400w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-23\" id=\"q-fire-schaltbox-generatorseitige-dc-trennung\" style=\"font-size:20px\"><br><strong>QFire Switch Box \u2013 DC Isolation on the PV Array Side<\/strong><\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-24 wp-block-paragraph\" style=\"font-size:16px\"><br>The QFire switch box provides galvanic isolation of the connected PV strings. The number of strings, DC ratings, connections and optional protective components are specified to suit the project.<\/p>\n<\/div><\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch dc-card has-border-color is-layout-flow wp-block-column-is-layout-flow\" style=\"border-color:var(--nv-light-bg);border-width:1px;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);flex-basis:33.34%\">\n<div class=\"wp-block-group\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-group is-vertical is-content-justification-center is-layout-flex wp-container-core-group-is-layout-524f8de7 wp-block-group-is-layout-flex\">\n<figure class=\"wp-block-image size-medium wp-container-content-b0827016\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Q3-ATS-Box-Netz-und-Ersatzstromversorgung-300x300.webp\" alt=\"\" class=\"wp-image-11402\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Q3-ATS-Box-Netz-und-Ersatzstromversorgung-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Q3-ATS-Box-Netz-und-Ersatzstromversorgung-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Q3-ATS-Box-Netz-und-Ersatzstromversorgung-768x768.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Q3-ATS-Box-Netz-und-Ersatzstromversorgung.webp 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-25\" id=\"q-fire-steuerbox-zentrale-sicherheitsauslosung-1\" style=\"font-size:20px\"><br><strong>Q3 ATS Box \u2013 Grid and Backup Supply<\/strong><\/h3>\n<\/div>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-26 wp-block-paragraph\" style=\"font-size:16px\"><br>The Q3 ATS box is a standalone grid\/backup transfer assembly for three-phase building supplies up to 630 A.<\/p>\n\n\n\n<p class=\"has-text-align-center has-neve-text-color-color has-text-color has-link-color wp-elements-27 wp-block-paragraph\">A four-pole transfer switch switches the line conductors L1, L2 and L3, together with the neutral conductor N. The protective conductor PE remains continuously connected.<\/p>\n<\/div><\/div>\n<\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:55px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide\" id=\"q-fire-ac-dc-abschaltkonzept-fur-pv-anlagen-auch-mit-speicher-und-ersatzstrom\">QFire AC\/DC Shutdown Concept for PV Systems \u2013 Including Battery Storage and Backup Power<\/h2>\n\n\n\n<p class=\"alignwide wp-block-paragraph\"><strong>One central trigger. Coordinated isolation of defined DC and AC circuits.<\/strong><\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1200\" height=\"614\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire-AC-DC-\u2013-PV-Safety-Shutdown-System-including-Battery-Storage-and-Backup-Power.webp\" alt=\"\" class=\"wp-image-11580\" title=\"QFire AC DC \u2013 Feuerwehrschalter f\u00fcr PV-Anlagen mit Speicher und Ersatzstrom\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire-AC-DC-\u2013-PV-Safety-Shutdown-System-including-Battery-Storage-and-Backup-Power.webp 1200w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire-AC-DC-\u2013-PV-Safety-Shutdown-System-including-Battery-Storage-and-Backup-Power-300x154.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire-AC-DC-\u2013-PV-Safety-Shutdown-System-including-Battery-Storage-and-Backup-Power-1024x524.webp 1024w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/QFire-AC-DC-\u2013-PV-Safety-Shutdown-System-including-Battery-Storage-and-Backup-Power-768x393.webp 768w\" sizes=\"auto, (max-width: 1200px) 100vw, 1200px\" \/><\/figure>\n<\/div>\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\"><span aria-hidden=\"true\" class=\"wp-block-cover__background has-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-block-cover-is-layout-constrained\">\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h2 class=\"wp-block-heading alignwide\" id=\"q-fire-ac-dc-weil-sicherheit-nicht-am-netzanschluss-endet\">The Added Value: One Safety Concept for Multiple Energy Sources<\/h2>\n\n\n\n<p class=\"alignwide wp-block-paragraph\">The modular combination enables a project-specific safety architecture based on coordinated, standalone Q3 components \u2013 without having to develop an entirely new shutdown system for every installation configuration.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:10px\" 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-columns alignfull is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-stretch 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=\"entscheidend-bei-hybridanlagen-ruckspeisepfade-berucksichtigen\" class=\"wp-block-heading\">Essential for Hybrid Systems: Accounting for Backfeed Paths<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Galvanic isolation of the PV strings interrupts the connection between the PV array and the downstream DC installation at the respective QFire switching point.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It does not necessarily mean that all DC cables throughout the system are de-energised.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Depending on the inverter and battery storage architecture, cable sections between the QFire switch box and the hybrid inverter may remain energised through internal DC connections or other backfeed paths.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">System design must therefore consider all relevant energy sources and potential backfeed directions, as well as the string isolation points.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The additional ATS disconnection specifically addresses the AC supply to the connected building circuits. It does not replace any separate battery isolation or DC backfeed isolation that may be required.<\/p>\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--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=\"q-fire-ac-dc-fur-die-professionelle-anlagenplanung\" class=\"wp-block-heading\">QFire AC\/DC for Professional System Design<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">QFire AC\/DC is a combined system solution for PV installations in which PV array isolation, hybrid inverters, battery storage and backup power need to be incorporated into a common safety concept.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-medium is-resized\"><img loading=\"lazy\" decoding=\"async\" width=\"300\" height=\"300\" src=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-300x300.webp\" alt=\"QFire AC\/DC demonstration system for PV shutdown with backup power\" class=\"wp-image-11430\" style=\"width:auto;height:200px\" title=\"\" srcset=\"https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-300x300.webp 300w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-150x150.webp 150w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten-768x768.webp 768w, https:\/\/q3-energie.de\/wp-content\/uploads\/2026\/10\/Industrielle-Solarsteuerung-mit-QFire-Komponenten.webp 800w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\"><strong>Typical applications include:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Commercial and industrial buildings with PV and battery storage<\/li>\n\n\n\n<li>Installations with hybrid inverters and automatic backup supply<\/li>\n\n\n\n<li>Buildings with additional requirements arising from fire protection and safety strategies<\/li>\n\n\n\n<li>Existing installations where PV shutdown is to be extended to include AC backup supply disconnection<\/li>\n\n\n\n<li>New-build projects with defined isolation points and central safety activation<\/li>\n<\/ul>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-vertically-aligned-stretch has-neve-text-color-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<h2 id=\"technische-eckdaten-der-q-3-ats-box-63\" class=\"wp-block-heading has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-28\">Key Technical Data for a Q3 ATS Box<\/h2>\n\n\n\n<figure class=\"wp-block-table ticss-b64683f3 is-style-regular\"><table class=\"has-nv-site-bg-color has-neve-text-color-background-color has-text-color has-background has-link-color\" style=\"border-top-style:none;border-top-width:0px;border-bottom-style:none;border-bottom-width:0px;border-left-style:none;border-left-width:0px\"><thead><tr><th>Feature<\/th><th>Specification<\/th><\/tr><\/thead><tbody><tr><td>Rated operational voltage<\/td><td>230\/400 V AC, 50 Hz<\/td><\/tr><tr><td>Rated current<\/td><td>Project-specific, from 63 A to 630 A<\/td><\/tr><tr><td>Changeover<\/td><td>Four-pole, L1\/L2\/L3\/N<\/td><\/tr><tr><td>Transfer switch<\/td><td>Telergon C1<\/td><\/tr><tr><td>Utilisation category<\/td><td>AC-32B<\/td><\/tr><tr><td>Energy metering<\/td><td>Three-phase, CHINT DTSU666. Other options on request<\/td><\/tr><tr><td>Communication<\/td><td>RS485 \/ Modbus<\/td><\/tr><tr><td>Enclosure<\/td><td>Example configuration: 500 \u00d7 400 \u00d7 200 mm<\/td><\/tr><tr><td>Degree of protection<\/td><td>IP66 when correctly installed<\/td><\/tr><tr><td>Installation environment<\/td><td>Indoors<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button is-style-secondary\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/download\/ATS_Automatic_Transfer_Switch_63_Datenblatt.pdf\" style=\"border-width:1px\"><strong>Download the Q3 ATS Box 63 Datasheet \u2014 Example Configuration \u2192<\/strong><\/a><\/div>\n<\/div>\n\n\n\n<div style=\"height:10px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p class=\"has-nv-site-bg-color has-text-color has-link-color wp-elements-29 wp-block-paragraph\" style=\"font-size:14px\"><em>The configuration described here is a standard product. Q3 ENERGIE also manufactures customer-specific and project-specific variants.<\/em><\/p>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<h2 class=\"wp-block-heading alignwide\" id=\"projektspezifische-auslegung-auf-basis-bewahrter-q-3-komponenten\">Project-Specific PV Shutdown Design with Battery Storage \u2013 Based on Proven Q3 Components<\/h2>\n\n\n\n<p class=\"alignwide wp-block-paragraph\">The QFire switch boxes are configured to suit the number of strings, system voltage, string currents, MPPT allocation and cable routing.<\/p>\n\n\n\n<p class=\"alignwide wp-block-paragraph\">For ATS integration, the hybrid inverter, battery connection arrangement, required AC rated current and the circuits to be supplied or isolated are also taken into account.<\/p>\n\n\n\n<p class=\"alignwide wp-block-paragraph\">This forms the basis of a coordinated QFire AC\/DC system with clearly defined DC and AC switching points.<\/p>\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-neve-text-color-background-color has-background-dim-100 has-background-dim\"><\/span><div class=\"wp-block-cover__inner-container is-layout-constrained wp-block-cover-is-layout-constrained\">\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h2 class=\"wp-block-heading alignwide\" id=\"QFire-AC-DC-\u2013-Because-Safety-Does-Not-End-at-the-Grid-Connection\">QFire AC\/DC \u2013 Because Safety Does Not End at the Grid Connection<\/h2>\n\n\n\n<p class=\"alignwide wp-block-paragraph\">PV shutdown with battery storage and backup power: developed and implemented by Q3 ENERGIE \u2013 with project-specific design, coordinated components and direct access to our technical team.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div style=\"--wp--block-button--width: 75;\" class=\"wp-block-button is-style-secondary has-custom-width wp-block-button__width wp-block-button__width-75\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/qfire-big-pv-firefighter-safety-switch\/\" style=\"border-width:1px\">Learn More About QFire \u2192<\/a><\/div>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<div class=\"wp-block-buttons is-layout-flex wp-block-buttons-is-layout-flex\">\n<div style=\"--wp--block-button--width: 75;\" class=\"wp-block-button is-style-secondary has-custom-width wp-block-button__width wp-block-button__width-75\"><a class=\"wp-block-button__link wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/products\/project-inquiry\/qfire-pv-firefighter-switch\/\" style=\"border-width:1px\"><strong>Enquire about QFire AC\/DC \u2192<\/strong><\/a><\/div>\n<\/div>\n<\/div>\n<\/div>\n\n\n\n<div style=\"height:50px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<\/div><\/div>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/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<h2 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-30\" id=\"projektanfrage-feuerwehrschalter\" style=\"font-size:20px\">Project Inquiry Firefighter Switch<\/h2>\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-31 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 style=\"--wp--block-button--width: 100;\" class=\"wp-block-button is-style-primary q3-card-link has-custom-width wp-block-button__width wp-block-button__width-100\"><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<h2 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-32\" id=\"technische-unterlagen-feuerwehrschalter\" style=\"font-size:20px\">Technical Documentation Firefighter Switch<\/h2>\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-33 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 style=\"--wp--block-button--width: 100;\" class=\"wp-block-button is-style-primary q3-card-link has-custom-width wp-block-button__width wp-block-button__width-100\"><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:\/\/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<h2 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-34\" id=\"funktionsweise-technik-q-fire\" style=\"font-size:20px\">QFire Operating Principle <br>and Technical Details<\/h2>\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:\/\/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-35 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 style=\"--wp--block-button--width: 100;\" class=\"wp-block-button is-style-primary q3-card-link has-custom-width wp-block-button__width wp-block-button__width-100\"><a class=\"wp-block-button__link has-medium-font-size has-custom-font-size wp-element-button\" href=\"https:\/\/q3-energie.de\/en\/technology\/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<h2 class=\"wp-block-heading has-text-align-center has-nv-text-dark-bg-color has-text-color has-link-color wp-elements-36\" id=\"faq-zum-thema-feuerwehrschalter\" style=\"font-size:20px\">FAQ on Firefighter Switches<\/h2>\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-37 wp-block-paragraph\" style=\"font-size:16px\">Answers to frequently asked questions about applications, standards, activation concepts, installation requirements and operation.<\/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 style=\"--wp--block-button--width: 100;\" class=\"wp-block-button is-style-primary q3-card-link has-custom-width wp-block-button__width wp-block-button__width-100\"><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","protected":false},"excerpt":{"rendered":"<p>The building is disconnected from the grid \u2013 but is its power supply actually isolated? Modern battery storage systems can continue to supply the building. QFire AC\/DC combines PV DC isolation with AC source disconnection. PV Shutdown with Battery Storage and Backup Power: When Grid Disconnection Is Not Enough Conventional PV shutdown concepts often focus&hellip;&nbsp;<\/p>\n","protected":false},"author":1,"featured_media":11590,"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-11564","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\/11564","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=11564"}],"version-history":[{"count":18,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/11564\/revisions"}],"predecessor-version":[{"id":11604,"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/pages\/11564\/revisions\/11604"}],"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\/11590"}],"wp:attachment":[{"href":"https:\/\/q3-energie.de\/en\/wp-json\/wp\/v2\/media?parent=11564"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}