Siemens 3RV2021-1KA10 Manual Motor Protector 3 Pole

Siemens 3RV2021-1KA10 is a three‑pole manual motor protector (motor protection circuit breaker) designed for protecting 3‑phase motors in control cabinets. It provides overload protection with a current setting adjustable from 9 to 12.5 A and is rated for up to 690 V AC, making it suitable for a wide range of motor applications. The unit features screw‑terminal wiring and is typically offered in DIN‑rail mounted, size S0 configurations. It operates with AC‑3 duty and includes Class 10 thermal overload protection for reliable motor starting and safe disconnection during overloads. A manual rotary ON/OFF handle enables easy local control, and the device includes phase‑loss protection to help prevent motor damage from a missing or lost phase. Common applications include motor starters and compact motor protection in machine control panels, where integrated overload and short‑circuit protection in a single compact device simplifies wiring and panel layout.