Selective RC unit for the 5SL4 line
The Siemens 5SM2626-2 is a selective residual current unit (RC unit) from the SENTRON family, designed for use with the 5SL4 miniature circuit breaker series. It provides a 300 mA AC fault-current trip threshold at a rated current of 63 A and a rated voltage of 230/400 V AC, 50 Hz. The selective design means it delays tripping during short-duration earth faults, allowing downstream RCDs to clear first — this keeps upstream circuits live and avoids a full-panel blackout on a single branch fault.
Depth is 70 mm, matching the 5SL4 breaker depth for a flush panel layout. Conductor range: 1.5 to 25 mm² solid or stranded. Supply connection can be top or bottom.
Rated current of 63 A holds at ambient temperatures up to 45 °C. Above that, the unit derates: 58.59 A at 40 °C (note: this is the same as the 45 °C figure in the spec), 56.7 A at 50 °C, 54.81 A at 55 °C, 53.55 A at 60 °C, 52.29 A at 65 °C, and 50.4 A at 70 °C. Overvoltage category III.