The Fire Safety Rapid Shut Down Switch for Solar Panels

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The Fire Safety Rapid Shut Down Switch for Solar Panels

The BFS-S4 Fire Safety Switch

The BFS-S4 is a firefighter isolation switch for solar installations. Fire safety switches are required by insurance companies in all solar-powered buildings. This tailored solution ensures robust fire protection and total insurance compliance. The BFS-S4 fire safety switch is a string level load break disconnect device. It’s meant for solar rooftop installations, and it’s designed to protect firefighters and building infrastructure.

This device offers a variety of disconnect methods to remove high DC voltage and avoid the risk of electrocution. This model provides a reliable DC disconnect solution, which functions mechanically and delivers complete isolation in the event of a fault. Manual shutdown is also available, with fire services able to isolate DC power without being rooftop. The switch is activated with a motorised device.

The BFS-S4 delivers:

  • Over temperature protection — automatic shutdown
  • Main AC power shutdown — manual operation
  • AC power loss triggers DC power — automatic shutdown
  • Keeps DC power isolated and disconnected, even when AC power comes back

This device helps to protect firefighters from DC electric shock. The IP66 aluminium enclosure features a breathing valve, and a protection cover for rooftop installations is also available. The BFS-S4 fire safety switch is a genuine MC4 plug-and-play device with a Ul508i listed and IEC PV2 DC switch.

1 Solar PV String Rapid Shutdown Box

2 Solar PV Strings Rapid Shutdown Box

3 Solar PV Strings Rapid Shutdown Box

4 Solar PV Strings Rapid Shutdown Box

Available online


BFS-S4 highlights:

  • Up to 1500V DC
  • Up to 50 Amp
  • 4 strings
  • IP66 aluminium enclosure with breathing valve
  • UL508i listed and IEC PV2 DC switch
  • 25-year warranty
  • Original plug-and-play MC4 connectors
  • Protection cover for rooftop installations is available

If you demand operational confidence and insurance compliance, the BFS-S4 switch is an unbeatable fire safety solution.



Designer and developer of solar photovoltaic systems from 1kW to Megawatt range. Steve worked for Alstom and General Electric for 11 years. He develops solar inverter and complete systems with energy storage that are affordable, easy to install, and have a quick return on investment.

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