The presented fire safety switch is a four-chain version model, that is, it will handle four independent strings of photovoltaic modules. When an AC power outage is detected on the side of the distribution network, the switch prevents further DC power flow in the installation, resulting in increased safety of firefighting operations. For use in residential and commercial installations. S-BOX operates in accordance with globally standardized firefighting procedures. The task of the S-BOX, is to automatically break the DC circuit, in the event of a fire or grid failure, so that solar cables passing through the building do not remain live in the event of an anomaly. The AC power supply means that a power cut at the building's main switchboard will result in an automatic DC cut from the inverter. The return of AC power will result in the DC circuit being switched on.