Siemens 3rn1010-1cn00 Motor Protection Relay

Siemens Simirel 3RN1010-1CN00 Thermistor motor protection relay provides real-time motor temperature monitoring via a PTC sensor input and, when overheating is detected, switches the motor circuit through its SPDT output (1 normally open and 1 normally closed contact). It is designed for 24 V AC/DC control circuits and is part of the Siemens SIMIREL 3RN1 family, suitable for DIN-rail mounting with wiring options including screw terminals or spring-loaded terminals. It accepts a single sensor circuit to monitor motor winding temperature and is commonly used to protect pumps, conveyors, fans, and compressors by signaling faults or trip conditions when a temperature limit is reached. The 3RN1010 family includes variants such as 3RN1010-1CB00 and 3RN1010-1CM00 that share this thermistor-based protection concept and SPDT contact arrangement, and Siemens catalogs document the 24 V control supply and wiring options for these devices.