Reliability and duty-cycle profile
The 3RN2011-1BW30 is a SIRIUS 3RN2 standard evaluation unit for thermistor motor protection, with ATEX approval and built-in open-circuit and short-circuit detection in the sensor circuit. Its MTBF of 97 a and MTTFd of 303 a give a quantified reliability picture for a motor protection relay that sits in the control circuit, not the power path — the failure mode is loss of thermal monitoring, not a motor fault, but the consequence is unplanned downtime if the relay fails to trip on an over-temperature event. Rated supply is 24...240 V AC/DC, covering most common control voltages without needing a separate transformer tap. The relay operates over -25 to +60 °C ambient and stores down to -40 °C — the storage range governs handling during shutdowns, not running conditions.
Integration and mounting constraints
Width is 22.5 mm, height 100 mm, depth 90 mm. No spacing required in any direction — upwards, downwards, forwards, backwards, and at the side all specify 0 mm clearance. That means it can be packed tight in a crowded DIN-rail row without derating for airflow. Terminals accept solid and stranded conductors 20...12 AWG (1x 20...12, 2x 20...14 for solid). The connector pitch is standard for 22.5 mm housings; strip length is typical for spring-cage or screw terminals on this class of relay.