The Siemens 3RN2000-2AA30-Z X90 is a compact thermistor motor protection relay in a 17.5 mm enclosure, built for direct mounting on a DIN rail. It evaluates PTC thermistor inputs from motor windings or bimetallic temperature switches and trips a 1 changeover contact when the winding temperature exceeds the threshold. Supply is 24 V AC/DC, and the auto-reset function clears the trip once the thermistor cools, so the motor restarts without manual intervention. The 17.5 mm width saves rail space compared to a full-frame relay — three of these fit where one 45 mm unit sat.
RoHS compliant since 28 May 2009, with a REACH Article 33 duty-to-inform for lead (CAS 7439-92-1) above 0.1% w/w. The compliance documentation covers the standard EU substance restrictions for industrial control gear.