The Siemens SENTRON 5SM1344-6KK01 is a 4-pole RCCB rated 40 A at 400 V AC, 50 Hz, with a 30 mA trip threshold and Type A fault current sensitivity. It mounts on DIN rail and occupies 4 width units.
The 40 A current rating holds at ambient temperatures up to 45 °C without derating; above that, the allowable current drops in steps — 38.4 A at 50 °C, 36.8 A at 55 °C, 35.2 A at 60 °C, 33.6 A at 65 °C, and 32 A at 70 °C. Type A detects both sinusoidal AC residual currents and pulsating DC residual currents, covering most modern electronics and single-phase rectifier loads. Conductor termination accepts solid or stranded wire from 1.5 mm² to 25 mm², with a screw-terminal torque range of 2.5 to 3 N·m.
Mounting and integration notes
Mounts on DIN rail (REG) in any position — no orientation restrictions. Installation depth is 55 mm, fitting standard 60 mm deep enclosures. Supply can enter from top or bottom. Finger and back-of-hand safe construction meets the touch-protection requirements for panel builders working live.