The A9R50225 is a 2-pole residual current circuit breaker (RCCB) from the Schneider Acti9 iID K series, rated 25 A with 30 mA earth-leakage sensitivity. The insulation voltage is rated 440 V AC, giving headroom for transient overvoltages in a standard TN or TT system. The breaking capacity (Idm 500 A / Im 500 A) is the short-circuit withstand of the RCCB itself — adequate for domestic and light commercial sub-distribution where the upstream MCB or fuse limits fault energy. The residual current tripping technology is voltage independent, meaning the device does not require an external power supply to open on a fault — it uses the fault energy itself. This is a reliability advantage over electronic RCCBs in installations where neutral loss could otherwise blind the protection. Trip action is instantaneous, no time delay, so it coordinates as the fastest device in the protection chain.
Neutral is on the left, so verify busbar orientation if feeding from a pre-wired distribution block. Tunnel-type terminals accept 1...35 mm² rigid or 1...25 mm² flexible cable; strip length 16 mm, tightening torque 3.5 N.m. IP20 on the device body, IP40 inside a modular enclosure — suitable for dry indoor panel environments, not washdown zones.