What you're looking at
The Schneider Electric A9K23250 is a 2-pole Acti9 iK60N miniature circuit-breaker rated at 50 A with a B-curve trip characteristic. Thermal-magnetic trip means it handles overloads (thermal bimetal) and short-circuits (magnetic coil) in one package.
The B-curve (magnetic trip 3...5 x In) means this MCB trips magnetically between 150 A and 250 A. It is NOT for motor starts or transformer primaries where a C or D curve would be needed to ride through the inrush.
Panel integration
Clip-on DIN-rail mount, 36 mm wide (4 modules). Terminals accept 1...35 mm² rigid wire; strip 14 mm and torque to 3.5 N.m. IP20 finger-safe front. Padlocking device available for lockout/tagout. No earth-leakage protection built in — that's a separate RCD if needed. The ON/OFF toggle gives local indication; there's no remote contact-position indicator.
