The Siemens 3RN2011-2BA30 is a SIRIUS 3RN2 thermistor motor protection relay, designed to monitor motor winding temperature via PTC thermistors and trip on over-temperature, open-circuit, or short-circuit in the sensor circuit. Rated supply is 24 V AC/DC, occupying a single 22.5 mm DIN-rail slot — fits standard 35 mm rail via screw or snap-on mounting in any orientation. With an MTBF of 97 a and MTTFd of 303 a, the relay is built for long service in continuous-duty motor circuits; the ATEX approval and open/short-circuit detection make it suitable for hazardous-area motor protection loops.
For BOM freeze or PCN-watch purposes, this part is not subject to end-of-life notification at this time; it can be specified into new designs with confidence in ongoing supply.
Ratings in Context
The relay's output contacts are rated 1 A at 24 V, 0.2 A at 125 V, and 0.1 A at 250 V — these are the switching limits for the alarm/trip signal, not motor current; the thermistor loop itself is low-energy. The unit supports external reset and has no auto-reset or error memory, meaning it latches on trip and requires a manual or remote reset after the fault clears — standard for safety-related motor protection.
Width of 22.5 mm and height of 100 mm with 90 mm depth; mounts on 35 mm DIN rail with screw or snap-on, in any position. IP20 finger-safe enclosure. Terminals accept 20–12 AWG solid or stranded wire; clearance of 0 mm on all sides means no mandatory air gap to adjacent devices — can be packed tight on the rail.