Siemens Aktiengesellschaft 3RV1021-4BA10 Circuit Breaker

Siemens 3RV1021-4BA10 is a motor-protecting circuit breaker in the Sirius 3RV2 family, size S0 for compact motor applications in control panels. It provides a thermal-magnetic trip with Class 10 (A-release) characteristics and an adjustable overload range from 14 to 20 A, enabling coordination with a variety of motor FLA ratings. A 260 A short-circuit release supports rapid disconnection during fault events, while screw-terminal wiring offers secure connections in enclosure panels. Rated for a wide line-voltage range of 220 to 690 VAC and commonly used to protect motors up to about 7.5 kW, the device is suitable for DIN-rail mounting in standard control architectures. Siemens notes that this product has been phased out, with 3RV2021-4BA10 listed as the preferred successor; the catalog description specifically calls out “Circuit breaker size S0 for motor protection” and the 14–20 A adjustment range, reinforcing its role as a compact motor protector in industrial automation setups. Typical installation contexts include conveyor drives, pumps, fans, and machine tools in manufacturing or packaging lines.