The A9W22225 is an add-on residual current device (RCD) from the Schneider Electric Acti9 Vigi iC60 range, designed to clip onto the side of an iC60 miniature circuit breaker (MCB) with double terminals. It adds earth leakage protection to the circuit, tripping the connected MCB when it detects a fault current to ground. Rated at 25 A (In) on a 230/415 V AC network, it provides 100 mA sensitivity with Type A earth leakage protection — meaning it catches both sinusoidal AC residual currents and pulsed DC residual currents, which covers most modern electronic loads like switched-mode power supplies and variable speed drives. The trip is instantaneous (no time delay) and voltage-independent — the RCD will trip even if the supply neutral is lost, relying on the fault current itself to energize the trip solenoid. That makes it a solid choice for circuits where you need guaranteed disconnection regardless of supply conditions.
The 2-pole (2P) form factor means it protects both phase and neutral. The 63 mm width and 74 mm depth are standard for the Acti9 modular enclosure family, so it slots into existing distribution boards without surprises. Terminals accept rigid cable up to 25 mm² or flexible up to 16 mm², with a 14 mm strip length and 2 N·m tightening torque. The IP20 rating on the device body (IP40 inside a modular enclosure) is typical for panel-mount gear — not for wet locations, but fine inside a distribution board.
The 8/20 µs impulse withstand of 250 A per IEC 61009-1 means it handles surge currents from nearby lightning strikes or switching transients without nuisance tripping.