The Siemens 3RV1021-0EA15 is a SIRIUS motor protection circuit breaker rated for 0.4 A continuous current with a CLASS 10 trip characteristic — meaning it will trip within 10 seconds at 7.2× the set current, sized for protecting smaller motor loads like fractional-horsepower pumps or fans. The 100 kA breaking capacity at 400 V AC means it safely interrupts fault currents up to that level without cascading upstream, so it can be used in high-fault-capacity panels without needing a separate current-limiting fuse ahead of it. Phase failure detection is built in, so a lost phase on the line side causes a trip rather than single-phasing the motor.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width and 96 mm depth mean it occupies a single standard module slot on the rail, leaving adjacent space for a contactor or overload relay. Screw-type terminals on the main circuit accept solid conductors 2x (0.5…1.5 mm²) and 2x (0.75…2.5 mm²), or stranded 2x (1…2.5 mm²) and 2x (2.5…6 mm²). No auxiliary contacts are factory-fitted, but the transverse auxiliary switch design allows field-mounting a later block if needed. IP20 on the front means finger-safe but not washdown-rated — keep it inside the enclosure.