Motor protection circuit breaker for 0.4 A loads
The Siemens SIRIUS 3RV1021-0EA10-0FJ0-ZX95 is a motor protection circuit breaker rated for a continuous current of 0.4 A, sized for small motor and transformer loads on 400 V three-phase systems. Its CLASS 10 trip characteristic means it disconnects within 10 seconds at 7.2× rated current, matching the thermal curve of standard IEC induction motors during locked-rotor starts. The 100 kA breaking capacity at 400 V AC gives it the SCCR headroom to sit upstream of a contactor without requiring a separate fuse — a common panel-builder simplification for lines fed by a transformer with at least that fault current capability.
Phase failure detection and trip class
Built-in phase failure detection protects the motor against single-phasing — a leading cause of winding burnout in delta-connected loads. The CLASS 10 trip class is the standard for general-purpose squirrel-cage motors; it allows the inrush transient to pass while still clearing a sustained overload before the motor insulation reaches its thermal limit. The 0.09 kW power rating at 400 V confirms the motor size this breaker is designed to protect.
Mounting and integration
Mounts via screw or snap-on onto 35 mm DIN rail per DIN EN 50022. The 45 mm width occupies a single modular unit, leaving room for a contactor and overload relay in the same row. Screw-type terminals on the main circuit accept solid and stranded conductors up to 6 mm². Front face carries IP20 protection — safe for finger-probe access inside an enclosure. Ambient operating range of -20 to +60 °C covers most indoor panel conditions without derating.