What it is and what it does
The Siemens 5SM3312-6KK01 is a 2-pole residual current operated circuit breaker (RCCB) from the SENTRON 5SM3 family, rated 25 A at 230 V AC with a 30 mA trip threshold, Type A (pulsating DC and AC fault currents), short-time delayed to ride through nuisance trips from transient surges or equipment inrush. It mounts on a DIN rail (REG), occupies 2 width units (36 mm), and fits a standard 70 mm installation depth — a direct swap into any SENTRON subdistribution board or enclosure that accepts 2-pole RCCBs.
Key ratings and what they mean for fit
Rated 25 A continuous, 30 mA residual trip at 230 V AC. Short-circuit current rating of 10 kA at 230 V AC means the RCCB can safely interrupt a fault up to that level without welding its contacts or cascading damage upstream — adequate for most commercial and light-industrial subdistribution boards where the prospective fault current is under 10 kA. Type A detection handles both sinusoidal AC faults and pulsating DC faults (typical from rectifiers, VFDs, LED drivers), so it is the correct choice for circuits feeding electronic loads where a Type AC RCCB might fail to trip. Short-time delayed design (marked as short-time delayed, not instantaneous) gives a deliberate trip delay of a few milliseconds to coordinate with downstream MCBs and avoid nuisance tripping on motor start or capacitor inrush — a common spec for feeder RCCBs in industrial panels.
Installation and wiring notes
Terminals accept solid or stranded copper from 1 to 16 mm². Tightening torque is 2.5 to 3 N·m. Rated for 50 Hz only. Ambient operating range -25 to +45 °C; storage range -40 to +75 °C. IP20 with connected conductors in an installed distribution board. Mounting position any, supply feed from top or bottom. Mechanical service life 10,000 switching cycles typical.