Siemens 3RV1021-0KA10 Manual Motor Starter 4 HP

Siemens 3RV1021-0KA10 is a DIN-rail mounted manual motor starter and motor-protection circuit breaker (size S0) designed to protect small motors with adjustable overload protection and a fixed short-circuit release. The unit's thermal-magnetic overload is adjustable from 0.9 to 1.25 A, providing Class 10 protection for reliable starting and motor protection; the short-circuit release is rated at 16 A, and it uses screw terminals for straightforward wiring. Rated for voltages in the 220–690 VAC range, it is commonly listed with a power rating around 0.37 kW (approximately 0.5 HP) depending on operating voltage, making it suitable for light-duty motors such as fans, pumps, and conveyors in compact control panels. Siemens notes that 3RV1021-0KA10 is a phased-out model with the recommended successor 3RV2011-0KA10, so buyers planning new installations should verify availability or consider the newer Sirius 3RV2 family for continued support.