The Siemens 3RN1013-2BW00 is a thermistor motor protection evaluation unit from the SIRIUS family, designed to monitor motor winding temperature via PTC thermistors and trip a 2 CO contact output on overtemperature or sensor fault. It accepts a universal AC/DC supply covering 24 to 240 V at both 50 and 60 Hz, so it drops into panels with mixed control voltages without a separate power supply module.
The 22.5 mm width and 103 mm height match the standard single-module DIN-rail footprint, fitting into crowded enclosures where every millimeter counts. Depth of 91 mm is shallow enough for most 120 mm deep cabinets. Two CO (changeover) contacts give you both a normally-open and normally-closed signal path per contact — enough to drive a PLC input and a local alarm lamp simultaneously without external relays. The built-in reclosing lockout prevents automatic restart after a trip, which is critical for applications where manual reset is required by code or safety procedure. Spring-loaded terminals (cage-clamp style) speed wiring and hold up better under vibration than screw terminals — a real advantage on a motor starter or in a mobile panel.