Fire safety switch PROJOY PEFS-EL50H-8 (MC4), 4 strings PEFS-EL50H-8-P2

Fire safety of photovoltaic installations

The PROJOY PEFS series safety switch is a key protective element in photovoltaic installations, ensuring the automatic disconnection of PV panels from the system in emergency situations. In the event of a fire in a building with a photovoltaic installation, after manual AC power disconnection on the inverter side, the device automatically isolates the photovoltaic panels from the rest of the system, effectively eliminating high DC voltage from the PV installation.

The main task of the switch is to protect rescue teams from potential electric shock during firefighting operations on the PV installation. After firefighters detect a grid failure and disconnect the alternating current (AC), the device automatically interrupts the DC circuit after 5 seconds. This mechanism makes firefighting operations safe and simultaneously minimizes potential damage to the photovoltaic installation itself.

Operating parameters and performance

The switch supports up to 4 strings simultaneously, providing a maximum current of up to 50A per string at a maximum voltage of up to 1500V DC. The operating voltage range is 300~1500V DC, making the device compatible with most standard photovoltaic installations.

The response time of the switching mechanism is just 5 milliseconds, which guarantees lightning-fast electric arc interruption and immediate power cutoff. The device operates in a temperature range from -20°C to +50°C, and automatic shutdown occurs at a temperature of +70°C, protecting against overheating.

Application and functionality

The PEFS switch is particularly useful during maintenance work carried out by the power utility. After the loss of AC grid voltage, it automatically interrupts the DC circuit in the photovoltaic installation, which results in the disconnection of voltage on the AC side of the inverter and positively affects its durability.

The device is also invaluable during repairs or maintenance work performed within the photovoltaic installation at a customer's site. After AC power is restored, the switch automatically resets - closing the circuit without the need for user intervention. Additionally, it provides greater reliability and safety through power line monitoring.

Construction and certification

The housing is made of robust plastic with an IP66 protection class, ensuring full resistance to weather conditions and dust tightness. The materials used in the construction are fire-resistant class V-0 and UV-resistant, guaranteeing a 25-year lifespan.

The device is equipped with all necessary international certificates: CE, TUV, CB, SAA, UL, and CCC. It also includes a breather valve to protect against water vapor condensation inside the housing and prepared cable entries with standard MC4 connectors for easy installation.

The built-in DC isolator has full TUV, CE, CB, SAA, UL, and CCC certification documentation. The switch complies with the EN60947-1&3 standard requirements for DC disconnection and is rated for over 10,000 operations (>1500 operations under load).