The Siemens 3RN1013-1BW01 is a thermistor motor protection evaluation unit from the SIRIUS 3RN1 series. It monitors motor winding temperature via PTC thermistors and trips when the threshold is exceeded, protecting against overheating. The unit operates on AC/DC supply voltage from 24 to 240 V at 50 or 60 Hz, making it suitable for global installations without voltage module changes.
The 24 to 240 V AC/DC supply range covers standard control voltages from 24 VDC panels up to 240 VAC line-powered controls, so one part number fits both architectures. Two CO (changeover) auxiliary contacts provide the trip signal — one for the motor contactor coil, the other for a PLC or status lamp. The LED display gives local visual indication of operating state and fault conditions without needing a connected HMI.
This evaluation unit is designed for motor thermal protection in control panels. It connects to PTC thermistors embedded in motor windings and provides a relay output to drop out the motor contactor on overtemperature. Typical applications include conveyors, pumps, fans, and compressors where the motor is at risk of overload or blocked cooling. The reclosing lockout function prevents automatic restart after a trip, which is critical for unattended or remotely monitored equipment.
The 3RN1013-1BW01 is a phased-out product. The preferred successor is 3RN2012-1BW31, a multifunctional evaluation unit with manual/auto/remote modes and short-circuit detection.