The Schneider Electric A9Z31225 is a 2-pole residual current circuit breaker (RCCB) from the Acti9 iID series, rated 25 A with 30 mA earth-leakage sensitivity. The Type A-SI (Super Immunised) designation means it handles pulsed DC fault currents (from rectified loads like VFDs, UPS, or LED drivers) without nuisance tripping from high-frequency leakage or transient surges. Voltage-independent trip mechanism means it clears a ground fault even if the line voltage collapses — no auxiliary supply needed.
Breaking capacity and short-circuit coordination
Rated breaking capacity is 1500 A (Idm and Im), and the rated conditional short-circuit current is 10 kA. That 10 kA figure is the maximum prospective fault current the RCCB can withstand when backed by an upstream overcurrent device (typically an MCB or fuse) — it's not a standalone interrupting rating. The 1500 A is what the RCCB itself can break. The impulse withstand is 3000 A at 8/20 µs waveform, so it survives lightning-induced surges common on overhead supply lines.
Clip-on mount to standard 35 mm DIN rail. Neutral is on the left. Torque to 3.5 N.m. Wire strip length 14 mm. IP20 on the body, IP40 inside a modular enclosure. Padlocking provision for lockout/tagout.
Production status is current — this is an active catalogue part, not a phase-out or NRND line. The Acti9 iID series is Schneider's standard RCCB family for residential and commercial distribution boards.