RCCB for 63 A feeder circuits
The Siemens 5SM3646-6 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, rated 63 A at 400 V AC, 50 Hz, with a 10 kA short-circuit current rating. It detects Type A fault currents — AC sinusoidal and pulsating DC — making it suitable for circuits with single-phase rectifiers or electronic loads. The instantaneous trip design means no intentional time delay, so it clears ground faults as fast as the loop impedance allows. Mounts on DIN rail (REG), 4 width units, and accepts top or bottom feed.
Full 63 A rating holds up to 45 °C ambient. Above that, the continuous current derates stepwise: 60.48 A at 50 °C, 57.96 A at 55 °C, 55.44 A at 60 °C, 52.92 A at 65 °C, and 50.4 A at 70 °C. Mounting position is unrestricted, which simplifies panel layout in tight enclosures.
Physical fit and protection class
Finger and back-of-hand touch-safe per the design. Silicon-free construction, which matters for potting or conformal-coating processes.
Fault current withstand and test circuit
Permissible I²t value of 70 000 A²·s and a surge current resistance of 1 kA. The test circuit requires a minimum of 100 V to operate. Functional designation per DIN EN 61346-2 and DIN EN 81346-2 is F.