RCCB for selective fault protection
The Siemens 5SV3612-6BA is a 2-pole residual current circuit breaker (RCCB) from the SENTRON 5SV3 series, rated 25 A at 230/400 V AC with a 300 mA tripping residual current. Rated short-circuit current withstand is 10 kA, and the I²t value of 58,000 A²·s gives the upstream protective device a defined energy window for coordination. The 300 mA threshold suits circuits where nuisance tripping from leakage in IT equipment or long cable runs would be a problem — think sub-distribution boards feeding office floors or small machine cells.
Terminal capacity accepts solid or stranded conductors from 0.75 to 35 mm², which covers everything from 1.5 mm² lighting circuits up to 10 mm² feeder tails. Finger and back-of-hand safe terminals allow live working in the panel without additional shrouding — a practical consideration for commissioning engineers who need to verify voltage on the load side.
Thermal performance and derating
Derating begins at 65 °C (23.3 A,) and drops to 17.62 A at 70 °C. For a panel running at 50 °C ambient — typical for a sealed enclosure with drives — this RCCB delivers its full 25 A without headroom loss. Storage range is -40 to +75 °C.