Siemens 3RN1013-1BW10 Monitoring Relay

Siemens 3RN1013-1BW10 Monitoring Relay is a thermistor-based motor protection device that monitors motor-winding temperature via an attached thermistor sensor and outputs a protection signal to guard against overheating. It provides two Form C (DPDT) switching outputs, enabling independent alarm signaling or interlock/shutdown circuits within a single inline unit. The device is designed for a supply range of 24 to 240 V and supports both AC and DC inputs with safe isolation between input and output circuits, making it suitable for integration into safety and control networks in industrial equipment. This model is listed as a phased-out product in Siemens’ catalog, with the recommended successor 3RN2013-1BW30 continuing the thermistor motor protection function within the same voltage range. In typical installations, the relay is connected in motor protection schemes alongside starters or drives; thermistor leads connect to the relay’s input, and the DPDT contacts are used to trigger alarms or control actions when the monitored winding temperature exceeds the preset limit, helping prevent motor damage and reducing downtime.