RCBO for final-circuit protection with residual-current detection
The Siemens 5SU1624-7KK82 is a SENTRON RCBO (residual-current circuit breaker with overcurrent protection) combining a 2-pole MCB and a Type A RCD in one 7-module-wide unit. Rated 125 A at 30 °C with a C tripping characteristic, it clears overcurrents fast enough for motor-start and lighting inrush while the 300 mA Type A residual element catches pulsating DC fault currents that a plain AC RCD would miss. Breaking capacity is 10 kA per both EN 60898 and IEC 60947-2, so it handles high-fault-current utility feeds in commercial and light-industrial distribution boards.
Full rated current holds at 30 °C ambient; derate linearly to 96.25 A at 60 °C. The 77 mm depth and 90 mm height fit standard distribution-board cutouts; 7 modular-width units (each 18 mm) occupy 126 mm of DIN-rail space.