The Siemens 5SM9446-0 is a SENTRON residual current (RC) unit, type AC, designed as a companion module for the 5SL4 miniature circuit breaker. It provides earth leakage protection on 4-pole circuits up to 63 A rated current, with a 100 mA trip sensitivity and a rated voltage of 400 V AC. It is an instantaneous device — no intentional short-time delay — so it clears ground faults within the standard response time for personnel protection.
Installation depth is 70 mm. The supply connects at the top, above the 5SL4 MCB.
