The Siemens 5SM3314-6KK12 is a 2-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, rated 40 A at 230 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 the standard choice for circuits with electronic loads like switched-mode power supplies or variable-speed drives where pure AC detection would miss half-wave faults.
The 40 A rating holds steady at 40 A up to 45 °C ambient, then derates linearly to 32 A at 70 °C — a useful curve if the RCCB shares a crowded DIN rail with heat-generating contactors or power supplies. Type A detection is required by IEC 60364 for circuits with single-phase rectifiers; if your load is purely resistive (heater, incandescent lighting), a Type AC would also work, but Type A is the safer default for mixed loads.
Snaps onto a standard 35 mm DIN rail, occupies 2 width units (36 mm wide), and accepts solid or stranded conductors from 1 to 16 mm² — covers everything from 1.5 mm² lighting circuits up to 10 mm² feeder tails. The 70 mm depth fits flush in most 80 mm deep enclosures; no extra gland plate clearance needed.
No last-time-buy or phase-out notice is associated with this order code.