The Siemens 5SM3314-6KL12 is a 2-pole residual current operated circuit breaker (RCCB) from the SENTRON 5SM3 series, rated for 40 A at 230 V AC with a 30 mA trip threshold and Type A fault current detection. The instantaneous design (no short-time delay) means it trips within the first cycle of a fault, which is the expected behaviour for personnel protection at 30 mA.
Installation and wiring constraints
Terminals accept solid or stranded conductors from 1 to 16 mm², with a tightening torque range of 2.5 to 3 N·m. Installation depth is 70 mm, which matches standard DIN-rail enclosure depths. The IP20 rating applies only when the distribution board is installed with connected conductors; the device itself is finger and back-of-hand safe per the touch-protection design. The overvoltage category is III (fixed installation with downstream sub-distribution). The test circuit requires a minimum of 100 V AC to function — verify supply voltage at the test button before commissioning.