The Siemens 3RV2021-4CA10 is a manual motor protector/starter that is adjustable from 17 to 22 AMPS, has phase loss protection and a rotary ON/OFF handle. This IEC rated motor protector offers Class 10 tripping, which will cut power in 10 seconds or less during an over current condition, screw terminals and mounts on standard 35MM DIN rail. Front and side mounted auxiliary contacts can be added to the 3RV2021-4CA10 for additional signalling applications and if a higher AMP range is needed,