The Siemens 3RN1010-1CM00 is a thermistor motor protection evaluation unit designed to monitor motor winding temperature via PTC thermistors. It operates on 230 V AC at both 50 and 60 Hz, making it a drop-in for standard European line voltages. The unit provides one normally-open and one normally-closed auxiliary contact for trip signaling and control interlocking.
The 22.5 mm width matches standard single-module DIN-rail footprint, so it fits alongside other 22.5 mm devices without crowding. Screw and snap-on mounting means it clips onto the rail and can be secured with a screw for vibration resistance — typical for panels in industrial environments.
The LED display version indicator gives a quick visual of trip status without needing a multimeter — useful during commissioning or fault-finding on a motor starter panel.