Siemens 3RV1021-1KA10 Circuit Breaker

Siemens 3RV1021-1KA10 Sirius motor protection circuit breaker, size S0, delivers Class 10 thermal-magnetic protection for small motors in control panels. It is rated for a motor current of 9–12.5 A and suits line voltages from 220 to 690 V AC, with a typical motor power rating up to 5.5 kW depending on supply. The device uses screw-terminal connections and is designed for DIN-rail mounting, with IP20 protection on the front and an operating ambient temperature range of -20 to 70 C (up to 2000 m altitude). Its instantaneous (short-circuit) release is rated at 163 A, and the unit provides a high short-circuit current interrupting capacity up to 100 kA at 400 V, ensuring safe disconnection under fault conditions. This model is part of Siemens Sirius 3RV1 family, intended for motor protection in compact automation circuits such as pumps, conveyors, and fans, where a compact, reliable protective device is required with straightforward wiring and a clear 9–12.5 A trip range.