The Schneider Electric A9KR11425BQ is a 4-pole residual current circuit breaker (RCCB) from the Acti9 ID K range, rated at 25 A with 30 mA earth-leakage sensitivity. It protects against earth faults in AC networks at 380-415 V AC, 50 Hz, and is intended for group incomer duty in distribution boards. Clip-on mounting to DIN rail and a 72 mm width mean it occupies four standard 18 mm modular spaces in the enclosure — plan the rail fill accordingly when laying out a multi-way board.
Terminals accept 1-35 mm² rigid or 1-25 mm² flexible cable, with a wire-stripping length of 14 mm and a tightening torque of 3.5 N·m. The biconnect design allows looping through top or bottom — useful for daisy-chaining outgoing circuits without extra junction blocks.
Compliance with IS 12640-1, EN/IEC 61008-1, and EN/IEC 61008-2-1 covers Indian, European, and international standards for RCCBs.
Rated breaking and making capacity is Idm 500 A / Im 500 A — sufficient for clearing a bolted fault on a 25 A circuit, but note that this is the RCCB's own short-circuit withstand; upstream overcurrent protection (MCB or fuse) must coordinate to keep fault energy within that limit. Electrical durability is 4000 cycles under AC-1 (resistive load) and mechanical durability 5000 cycles — fine for a distribution board that sees infrequent switching, but not rated for frequent manual operation like a switch-disconnector.