The Siemens 5SU1344-1KK82 is a SENTRON RCBO (residual current circuit breaker with overcurrent protection) — a 4-pole unit rated at 125 A operational current with a 30 mA residual trip threshold and a C tripping characteristic. It breaks fault currents up to 10 kA per EN 60898 and IEC 60947-2, so it handles both overload and earth-leakage protection in a single device, sized for main incomer or large sub-feed duty in a 50 Hz AC panel.
The 5SU1344-1KK82 occupies 11 modular width units (198 mm wide) with a 77 mm depth and 90 mm height, mounting in any position. It is designed for distribution-board installation with connected conductors, carrying IP20 protection once enclosed. The neutral conductor is switched internally, and the supply can enter from the top or bottom — no forced orientation.