The Schneider Electric A9K23425 is a 4-pole miniature circuit-breaker from the Acti9 iK60N series, rated 25 A at 30 °C with a B-curve trip characteristic (magnetic trip between 3 and 5 times In). Its 6 kA breaking capacity at 400 V AC (Icn per EN/IEC 60898-1) means it can safely interrupt a fault current up to 6000 A without welding contacts or cascading damage upstream — that's the standard domestic and light-commercial fault level for 400 V three-phase distribution boards across Europe and markets adopting IEC 60898-1. Clip-on mounting to a DIN rail (35 mm per EN 60715) and 72 mm width (8 x 9 mm pitches) mean it occupies exactly four module spaces in a consumer unit or sub-distribution board. The tunnel-type terminals accept up to 25 mm² rigid or 16 mm² flexible cable, with a 2 N·m tightening torque and 14 mm strip length — standard for a 25 A outgoing circuit. IP20 finger-safe terminals are fine for enclosed panels; no washdown rating here, so keep it inside the enclosure.
Coordination and selectivity notes
The thermal-magnetic trip unit gives a fixed thermal curve (ambient-compensated) and a magnetic threshold of 3–5 x In (75–125 A instantaneous). For motor-starting or transformer inrush, a C-curve or D-curve would be a better fit; the B-curve here is for general distribution.