The Siemens SIRIUS 3RN2013-2BW30 is a thermistor motor protection relay from the 3RN2 family, designed to monitor PTC thermistor sensors embedded in motor windings. The unit detects overtemperature via the sensor circuit and includes open-circuit and short-circuit detection in that same circuit, plus ATEX approval for use in potentially explosive atmospheres. The relay's response thresholds are set by a trip resistance initial value of 0.85 and a full-scale value of 1.1, consistent with standard PTC thermistor curves. It offers an auto-RESET function and a non-volatile error memory, meaning a fault condition is retained even after a power loss until manually acknowledged or the external reset input is activated.
Housed in a 22.5 mm wide enclosure, 100 mm tall, 90 mm deep, the relay mounts on a standard 35 mm DIN rail via screw and snap-on fastening. The IP20 protection class suits clean, dry control cabinets.
Output Ratings and Wiring
The relay outputs are rated for switching: 1 A at 24 V, 0.2 A at 125 V, 0.1 A at 250 V, and 0.2 A at 240 V (note the 0.2 ms switching time at 240 V likely refers to a transient rating or a specific test condition). These are low-current signal-level contacts, not intended for direct motor load switching. The outputs are electrically isolated from each other. The fastening method is screw and snap-on mounting; wiring is straightforward for a panel builder.