The Siemens 3RV1021-0HA10 is a SIRIUS motor protection circuit breaker rated for 0.8 A continuous current with Trip Class 10, designed to protect motors up to 0.18 kW at 400 V AC. Breaking capacity is a flat 100 kA across the voltage range from 240 V through 690 V AC, so it handles high-fault-current panels without cascading upstream breakers.
DIN-rail footprint and terminal specs
Width is 45 mm, depth 96 mm, height 97 mm. Zero clearance needed at the back or sides for heat dissipation — mount in any position. The screw terminals accept two conductors per pole: solid 1–2.5 mm² and 2.5–6 mm², or stranded with ferrules in the same ranges. AWG equivalent is 2× (14–10) for the main contacts.
Phase-failure detection and auxiliary switch readiness
Built-in phase-failure detection trips the breaker if one line drops — critical for preventing single-phasing on delta-connected motors. Ground-fault detection is not included. The product accepts an auxiliary switch (sold separately), so you can wire a status signal back to the PLC or safety relay without an extra contactor block.