The Schneider Electric A9R25492 is a 4-pole residual current circuit breaker (RCCB) from the Acti9 range, rated 125 A continuous current with 300 mA earth-leakage sensitivity. The 300 mA threshold means it protects against fault currents that could cause fire in cable insulation or equipment — it does not provide personnel shock protection (that requires 30 mA or lower). The selective time delay (marked S-curve) allows coordination with downstream RCCBs: in a fault, the downstream device trips first, keeping supply to healthy circuits.
Deployment context
The 4-pole format with neutral on the left suits three-phase outgoing feeders in distribution boards. IP20 body (IP40 in modular enclosure) means it is intended for indoor, dry-location panels, not washdown or outdoor installation. The tunnel-type terminals accept up to 50 mm² rigid or 35 mm² flexible cable, sized for the 125 A feed.
Designed and tested to IEC/EN 61008-1 and IEC/EN 61008-2-1, the core standards for residual current operated circuit-breakers without integral overcurrent protection. Carries VDE quality label. The 8/20 µs impulse withstand of 3 kA confirms immunity to surge events on the supply side.
