The Siemens 3RN1012-1BG00 is a thermistor motor protection evaluation unit from the SIRIUS 3RN1 family. It monitors motor winding temperature via PTC thermistors and trips on over-temperature, with a reclosing lockout function that prevents automatic restart after a fault until manually reset.
The 22.5 mm width matches a single DIN-rail slot. Depth is 91 mm. IP20 housing is typical for control cabinets. Two CO auxiliary contacts are built in, with no dedicated NC or NO contacts. Screw-type terminals accept standard conductors. Mount away from heat sources if the cabinet ambient regularly exceeds 50 °C.
Integration notes
Mounting is by screw and snap-on to 35 mm DIN rail. The fastening method allows both permanent screw-fixing and tool-less snap-on for quick panel assembly. The unit carries a reference code K per IEC 81346-2, which classifies it as a contactor/relay function in the plant documentation system. The display version includes an LED for status indication. The substance prohibitance date of 05/28/2009 indicates RoHS compliance.