Siemens 3RV1021-0HA10 Circuit Breaker Assembly

Siemens 3RV1021-0HA10 is a SIRIUS motor-protection circuit breaker (MPCB) sized for the S0 frame, designed to protect small motors and related control circuits in instrument panels. It provides overload protection with an adjustable A-release (0.55–0.80 A) and a fixed short-circuit release rated at 10 A, packaged with a screw-terminal connection and front IP20 protection. Rated for 220–690 VAC operation and intended for DIN-rail mounting, the device can include an auxiliary switch for remote signaling and has a power loss of about 6 W, along with an estimated 100,000 mechanical switching cycles. The model is listed by Siemens as no longer available and serves as the predecessor to the 3RV2 family, with 3RV2011-0HA10 named as the current successor; assembly references such as #299802 are associated with this part. Typically used for small-motor applications around 0.18 kW, this MPCB provides motor-protection functionality in a compact DIN-rail-ready package that combines isolating capability with protection in a single unit.