The Schneider Electric A9R71425 is a 4-pole residual current circuit breaker (RCCB) from the Acti9 iID series, rated 25 A with 30 mA earth-leakage sensitivity, Type AC. It is designed for outgoer circuits in distribution boards, providing earth-leakage protection on 380-415 V AC 50/60 Hz networks. The voltage-independent tripping technology means it operates without an external power supply, relying on the residual current itself to trigger the mechanism. Clip-on mounting on a DIN rail (8 x 9 mm pitches) and a 72 mm width per 4-pole module make it a direct swap in standard Acti9 or legacy Merlin Gerin panels.
It trips instantaneously — no intentional time delay — so nuisance tripping on circuits with high leakage from VFDs or long cable runs is possible. For those loads, a Type A or selective (S) RCCB would be a better fit; this Type AC unit is intended for sinusoidal AC residual currents only. The 6 kV impulse withstand voltage (Uimp) and pollution degree 3 rating suit it for installation in standard distribution enclosures without special derating for contamination. Terminals accept up to 35 mm² rigid or 25 mm² flexible cable, with a stripping length of 14 mm and tightening torque of 3.5 N.m.