RCCB for 400 V AC, 4-pole, 40 A, Type A
The Siemens 5SM3744-6 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, rated 40 A at 400 V AC, with a 500 mA tripping residual current and Type A fault-current sensitivity. Type A detection means it responds to AC sinusoidal residual currents and pulsating DC residual currents — the standard choice for circuits with single-phase rectifiers, switching power supplies, or electronic loads that generate pulsed DC fault currents.
The 40 A rating holds at ambient up to 45 °C. Above that, derate linearly: 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.
Installation and wiring
Snaps onto standard DIN rail, any mounting position.