Siemens 3RV1021-0KA10 Motor Starter Contactor

Siemens Sirius 3RV1021-0KA10 is a motor protector (motor starter protector) in the Sirius 3RV1 family, designed for DIN-rail mounting in control panels to guard small motors against overloads and short circuits. This size S0 device uses screw terminals, ships without an auxiliary contact, and provides thermal overload protection with a current setting in the 0.9 to 1.25 A range, plus a short‑circuit current rating up to 100 kA at 400 V. It is rated for 220–690 V AC and is intended for motor protection applications such as pumps, fans, compressors, conveyors, and other small three‑phase machinery in industrial controls, where compact protection and straightforward integration are advantageous. By interrupting fault current during overload or short‑circuit events, the 3RV1021-0KA10 helps prevent motor winding damage while meeting Class 10 trip characteristics, making it suitable as a compact, reliable protection element alongside standard contactors in a motor control circuit.