The Siemens 3RN2011-1BA30 is a SIRIUS 3RN2 thermistor motor protection relay — a standard evaluation unit with ATEX approval, open-circuit and short-circuit detection in the sensor circuit. Rated supply is 24 V AC/DC (50/60 Hz), and the output relay switches 1 A at 24 V, 0.2 A at 125 V, or 0.1 A at 250 V — sized for signaling a PLC input or a contactor coil, not for direct motor switching. The unit snaps onto 35 mm DIN rail (screw and snap-on) and measures 22.5 mm wide × 100 mm high × 90 mm deep, fitting standard control-panel rail without crowding adjacent devices.
Reliability figures: MTBF 97 a and MTTFd 303 a, reflecting a design intended for continuous duty in industrial environments. The reset is external (manual or remote) — no auto-reset, and no error memory, so after a trip the relay stays latched until explicitly reset. Galvanic isolation exists between input and output and between outputs, which simplifies wiring in mixed-voltage panels. Terminals accept solid or stranded wire: 1× (20–12 AWG) or 2× (20–14 AWG) solid, and 20–12 AWG stranded. Strip length and ferrule sizing follow standard Siemens SIRIUS practice.