Siemens 3RN1010-2CG00 Thermistor Motor Protection

Siemens 3RN1010-2CG00 Thermistor Motor Protection is a SIRIUS thermistor motor protection relay that guards motor windings from overheating by directly measuring winding temperature with PTC thermistors, triggering a protective trip when safe limits are exceeded. As part of the 3RN2 family, it provides two changeover contacts for control wiring and includes visual status indicators (READY and TRIPPED) to aid quick diagnostics in busy panels. The device is designed to be used with Siemens motor starters and drives to prevent thermal damage during overload, heavy starting, or inadequate cooling, and it offers galvanic isolation between the temperature-sensing circuit and the control logic. Typical applications include motors in pumps, fans, conveyors, and process equipment where accurate winding-temperature protection is essential.