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HISbox firefighter switch – safe shutdown of PV strings in the event of fire
Photovoltaic systems continue to generate electricity even after the grid supply has already been switched off. This is precisely where a risk arises in the event of fire: DC cables inside the building remain live and can endanger emergency responders. The HISbox firefighter switch ensures that DC voltage is reliably switched off in an emergency – automatically, quickly and in compliance with standards.
Maximum safety when it matters most
In the event of fire, every second counts. As soon as the fire brigade disconnects the building's main supply, the HISbox firefighter switch for generator connection boxes automatically de-energises the PV strings.
This allows rescue teams to extinguish fires safely, and the risks to people and buildings are significantly reduced.
Fire brigades, fire safety authorities and insurers increasingly demand this solution – the HISbox firefighter switch meets exactly these requirements.
Why a firefighter switch is important for PV systems
PV modules continue to produce energy as soon as light hits them. Even in an emergency.
This means:
DC cables inside the building remain active without shutdown
Firefighting and rescue operations are hampered
Risks to emergency responders increase
Insurers may impose conditions if no shutdown device is in place
The HISbox DC firefighter switch disconnects the DC strings at exactly the right point – at the building entry or directly near the modules. This prevents PV cables inside the building from continuing to carry voltage in the event of fire.
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We are happy to advise you on the right firefighter switch solution
How the HISbox firefighter switch works
Its operation is based on three intelligent triggering mechanisms that work independently of one another or in combination.
As soon as the fire brigade or service personnel interrupts the 230 V supply, the firefighter switch automatically disconnects the PV strings from the inverter.
Variants for every system architecture
The HISbox series offers a wide range of firefighter switch variants that adapt precisely to the design of modern PV systems. The combination of modular construction and project-specific configuration ensures that a firefighter switch variant is available for every solar installation.
1 to 12 MPPTs, each with different numbers of strings (ideal for small, medium and large rooftop systems)
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Areas of application and technical highlights
The HISbox firefighter switch is suitable for all systems in which DC cables are routed into the building or where increased fire safety requirements apply.
Commercial and industrial buildings
modern rooftop systems with many MPPT inputs
residential buildings where DC cables run through interior spaces
existing systems that are being upgraded to current fire safety requirements
repowering projects in which older PV systems are upgraded in terms of safety
Whether new build or refurbishment – the HISbox firefighter switch offers the same reliable shutdown function everywhere.
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