Motor protection circuit breaker, 1.25 A, CLASS 10 trip
The Siemens SIRIUS 3RV1021-0KA10-ZW96 is a 3-pole motor protection circuit breaker rated for 1.25 A continuous current, with a CLASS 10 trip characteristic and 100 kA breaking capacity across all common industrial voltages (240 V to 690 V AC). It is designed specifically for motor protection, meaning the thermal and magnetic trip curves are tailored to handle induction motor inrush without nuisance tripping, while still clearing a bolted fault fast. Phase failure detection is built in — if one line drops, the breaker trips on the remaining two phases, preventing single-phasing damage to the motor. This is a standard feature on the SIRIUS 3RV2 line and saves adding a separate phase monitor relay. Mounts via screw and snap-on onto 35 mm DIN rail per EN 50022, with zero clearance required at the sides or rear. Panel integration is straightforward: 45 mm wide, 97 mm tall, 96 mm deep. The IP20 front face keeps fingers out of the live terminals.
Sourcing & lifecycle
RoHS compliance date is 01.05.2012, which covers the EU RoHS scope. The SIRIUS brand carries CE, UL, CSA, and IEC certifications typical for industrial control gear, though specific approval markings should be verified against the nameplate for the target jurisdiction.
Wiring & terminals
Screw-type terminals on both main and auxiliary circuits. Accepts solid or stranded copper: 2x (1... 2.5 mm²) or 2x (2.5... 6 mm²) per clamp, or AWG 14–10 for the main contacts. Finely stranded wire with ferrule is also supported. No special tools beyond a standard screwdriver needed — field-serviceable without a crimper. Auxiliary switch expansion is possible (product extension auxiliary switch = Yes), so you can add a signal contact for remote status or PLC input without replacing the breaker.
Operating conditions
Rated for ambient operation from -20 to +60 °C, storage and transport from -50 to +80 °C. Shock rated at 25g for 11 ms. Maximum switching frequency is 15 operations per hour under AC-3 duty — fine for a pump or conveyor start/stop cycle, but not for rapid jogging. Power dissipation at rated current: 7.25 W total, 2.4 W per pole in hot operating state. Factor that into enclosure thermal calculations if the panel is densely packed.