The Siemens 3RN1022-1DW00 is a thermistor motor protection relay in the SIRUS form factor — 22.5 mm wide, 102 mm tall, 91 mm deep — designed to monitor motor winding temperature via PTC thermistor sensors. It accepts supply voltage from 24 to 240 V AC/DC, which covers most common control voltages across global panels without needing a separate transformer tap. The relay provides one normally open (NO) and one changeover (CO) auxiliary contact, giving a separate alarm and trip path. An integrated LED display shows operating status at a glance, and the reclosing lockout function prevents automatic restart after a trip — critical for motor protection where manual reset is required by code.
Mounts via screw and snap-on to 35 mm DIN rail. The 22.5 mm width fits standard single-module spacing; no extra gap needed between relays. Screw-type terminals accept up to 2.5 mm² stranded or solid wire. Ambient operating range is -25 to +60 °C, so it works in unheated enclosures or near motor starters. IP20 rated — keep it inside a cabinet, not in the washdown zone.