What this 63 A 4P MCB delivers in the panel
The Schneider Electric A9K12463 is a 63 A, 4-pole miniature circuit breaker from the Acti9 K60H series, built for distribution boards where you need a C-curve trip (magnetic release at 5 to 10 times In) and a 10 kA breaking capacity at 400 V AC per EN/IEC 60898-1. Rated 63 A continuous, it carries a 4-pole (4P) configuration — switching all four poles simultaneously, with the neutral pole protected. That's what you want for a three-phase + N distribution circuit where you need full isolation and overcurrent protection on the neutral as well. The 440 V rated insulation voltage (Ui) keeps it within standard 400 V three-phase networks.
The tunnel-type terminals accept 0.5 to 35 mm² rigid copper on both top and bottom, with a 14 mm wire strip length and 3.5 N·m tightening torque. That's a generous wire range for a 63 A breaker — you can land a 35 mm² feeder directly without a ferrule or reducer. IP20 finger-safe terminals are standard for enclosed panels; no touch-protection concern inside a closed distribution board.
The C-curve's 5-10x In magnetic threshold (315 to 630 A for a 63 A unit) is wide enough to ride through motor starting currents on small pumps or fans, yet fast enough to clear a hard short. For a commissioning engineer checking coordination: pair this with a 100 A or 125 A gG fuse or a higher-rated Acti9 MCB upstream, and you'll likely get full selectivity up to the 10 kA fault level.