The Siemens 5SM3346-3 is a 4-pole residual current circuit breaker (RCCB) from the SENTRON 5SM3 series, rated at 63 A and 400 V AC. It trips on a 30 mA Type F fault current — meaning it catches sinusoidal AC, pulsating DC, and mixed-frequency residual currents from variable-speed drives or EV chargers, which standard Type A devices miss. The 10 kA short-circuit current rating (SCCR) at 400 V ensures it withstands and interrupts high-fault events without upstream damage.
Above that, the device derates linearly: 60.48 A at 50 °C, 57.96 A at 55 °C, 55.44 A at 60 °C, 52.92 A at 65 °C, and 50.4 A at 70 °C.
Mounting and wiring in the panel
Snaps onto standard DIN rail (REG profile) and fits any mounting position. Accepts solid or stranded conductors from 1.5 mm² up to 25 mm², with screw terminals torqued to 2.5–3 N·m. Supply can land top or bottom; the design is short-time delayed (Type S equivalent) for selectivity with downstream MCBs. IP20 with the distribution board closed and conductors connected.