Siemens 3RV1021-1CA10 is a three‑pole motor protection circuit breaker (MCCB) in the S0 size, designed for DIN‑rail mounted motor protection in low‑voltage panels. It provides thermal‑magnetic protection with an adjustable overload release from 1.8 to 2.5 A and an instantaneous short‑circuit release rated at 33 A, with screw terminals for connection and a 220–690 V AC operating range. The unit is specified for up to 0.75 kW motors within that 220–690 VAC range and is designed for motor protection on three‑phase systems. Siemens lists 3RV1021-1CA10 as discontinued, with the successor 3RV2011-1CA10 in the Sirius/Siemens lineup.
