The Siemens SENTRON 5SV3644-6 is a 4-pole residual current circuit breaker (RCCB) rated 40 A, 300 mA, type A, for 400 V AC at 50 Hz. Instantaneous tripping, no short-time delay. The 10 kA short-circuit current rating (SCCR) matches the withstand of typical distribution board busbars in IEC 61008-1 installations. Mounts in any orientation. IP20 with conductors connected and distribution board installed. Silicon-free construction. Overvoltage category III.
The 300 mA sensitivity suits circuits where 30 mA nuisance tripping is a concern — typically subdistributions feeding fixed equipment, not socket outlets. The type A detection covers pulsating DC residual currents from rectifier loads.
Panel fit notes
Four-pole unit occupies 72 mm on the DIN rail. Depth 70 mm matches standard distribution board enclosure depths; no overhang on a 60 mm grid. Supply feed top or bottom. Ambient range -25 °C to 45 °C; storage down to -40 °C.