Siemens 3RV1021-1KA10 Molded Case Circuit Breaker

Siemens 3RV1021-1KA10 is a Sirius motor protection circuit breaker (MPCB) in the S0 size, a molded-case device that provides both overload and short-circuit protection for small motors. It is specified for a nominal current range of 9 to 12.5 A and operates from 220 to 690 V AC, making it suitable for motors up to about 5.5 kW at common industrial voltages. The unit is designed for DIN rail mounting with screw-type terminals for the main current path, and it belongs to the Sirius 3RV1 family known for compact motor protection solutions with a CL10 trip class. This specific 3RV1021-1KA10 part is used in control panels and motor circuits where space efficiency and reliable motor safeguarding are needed, enabling selective tripping and easy integration into standard MCCB-ready panel infrastructure.