The Siemens 3RN1022-2DW00 is a thermistor motor protection relay from the SIRIUS family, designed to monitor motor winding temperature via PTC thermistor sensors. It operates on a wide-range AC/DC supply of 24 to 240 V (50/60 Hz and DC), making it straightforward to drop into control panels with mixed voltage rails. The relay provides one normally open (NO) and one changeover (CO) contact for warning and switching-off functions, and includes a reclosing lockout feature to prevent automatic restart after a trip — critical for motor protection circuits where manual reset is required.
Housing is 22.5 mm wide, 103 mm high, 91 mm deep — the standard SIRIUS modular footprint that snaps onto DIN rail (screw and snap-on mounting). Spring-loaded terminals accept 0.2–2.5 mm² conductors; strip length around 8 mm. IP20 rated, so install inside a panel or enclosure. Ambient range -25 to +60 °C covers most industrial environments. The single NO + single CO contact handles the motor starter trip circuit and a separate alarm signal; no NC contacts on this variant, so plan the fail-safe logic accordingly.
RoHS compliance date is 2006-07-01 (substance prohibition date), covering the standard EU directive. The reference code per IEC 81346-2 is K (relay function). LED display on the front provides local status indication for quick fault-finding on the panel.