What is a Fireman Switch?
A fireman switch, also known as an emergency shut-off switch or a rapid shutdown switch, is a safety feature in a solar PV (photovoltaic) system. Its primary purpose is to provide a quick and safe way for firefighters or emergency responders to disconnect the solar panels from the electrical grid in the event of a fire or emergency.
Why does the Fireman Switch trip?
The switch can "trip" in the context of a solar PV system when it is activated to rapidly shut down the system. This can happen for several reasons:
Emergency Situations: The switch is designed to be manually or remotely activated by emergency personnel, like firefighters, when they need to quickly de-energize the solar PV system to make the area safe for their operations. If they need to cut off power to the system due to a fire or other emergency, they can activate the switch to trip it.
System Maintenance: The fireman switch may also be tripped during regular maintenance or testing procedures. This ensures that the switch is working correctly and that emergency personnel are familiar with how to use it.
Technical Issues: In some cases, technical issues with the switch or the wiring connecting it to the solar PV system could lead to unintended tripping. This is why regular maintenance and inspections are important to ensure the switch's reliability.
Wiring Faults: Wiring faults, such as short circuits or ground faults, in the solar PV system could potentially trigger the rapid shutdown switch to trip as a safety precaution. This is to prevent electrical hazards and fires caused by faults in the system.
Environmental Factors: Extreme weather conditions, such as lightning strikes or power surges, could cause the rapid shutdown switch to trip if the system detects an electrical anomaly.
Where is the Fireman Switch?
The fireman switch is typically installed close to your inverter. The fireman switch looks like this:
If the red light above the switch is flashing, it means the fireman switch has tripped.
To amend this issue, simply turn the fireman switch off. Leave it off for around 15 minutes. Turn the switch back on. The flashing red light should now be a steady red light.