The Siemens 5SM3414-0KL is a SENTRON 5SM3 series residual current operated circuit breaker (RCCB), 2-pole, Type AC, rated 40 A at 230 V AC with a 100 mA residual trip threshold. It is an instantaneous-trip device — no intentional short-time delay — designed for direct connection to the load side of an overcurrent protective device in a standard DIN-rail enclosure.
The 40 A rated current and 100 mA residual trip define its role: it protects a 40 A circuit against earth-leakage faults up to 100 mA, but it is NOT a combined MCB/RCCB — it provides no overcurrent or short-circuit protection, so it must be paired with an upstream MCB or fuse rated to interrupt the prospective fault current. The 2-pole configuration with N left switches both phase and neutral. The neutral terminal is on the left side of the device. Terminals accept 1 to 16 mm² solid or stranded copper, with a tightening torque of 2.5 to 3 N·m. The screw-type terminals are finger and back-of-hand safe per the IPXXB/IPXXC protection class.
Integration into the panel
Silicon-free construction is noted for applications where silicone outgassing can contaminate contacts or optics. The test circuit requires a minimum of 100 V AC to operate. Operating frequency is 50 Hz.