The Siemens 5SM3624-4KK14 is a 2-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, rated 40 A at 230 V AC with a Type B+ fault current characteristic and a 10 kA short-circuit current rating. It is short-time delayed (S-type selectivity), meaning it coordinates with downstream devices to avoid nuisance tripping on transient surges — the 3 kA surge current resistance backs that up.
Thermal derating and conductor sizing
The solid and stranded conductor cross-sections both accept 1.5 to 25 mm² — enough for the full rated current without over-sizing the terminal.
The 5SM3624-4KK14 is listed as current production (active lifecycle stage). No official successor has been published; the part is still the active catalog number for this rating and type.
Snap-on DIN rail (REG) mounting, any position accepted. Installation depth matches the 70 mm body depth — no extra clearance needed behind the rail. Finger and back-of-hand safe protection against electrical shock is built in, per the design.