Thermistor motor protection relay standard evaluation device with a 22.5 mm housing, spring-loaded terminal, 2 gold-plated changeover contacts, US = AC/DC 24 V-240 V, manual/automatic/remote RESET with ATEX approval. Equipped with 2 LEDs (READY/TRIPPED), safe galvanic isolation, test/RESET button, wire break monitoring, and short circuit monitoring. The SIRIUS 3RN2 thermistor motor protection relay protects motors from overheating, even in explosive environments, through direct temperature measurement with ATEX approval. The direct measurement of the motor winding temperature allows for the protection of a motor under unusual conditions such as heavy starting, braking operation, frequent switching, or inadequate cooling, thus avoiding the need for precautionary over-sizing of the motor. The devices can be used in gas or dust explosive areas. The use of PTC sensors eliminates the need for device parameterization. LEDs enable quick fault diagnosis. The devices are climate-resistant, touch-safe, and can be used worldwide thanks to a wide voltage range and international approvals. Available as mono- or bistable evaluation devices, with or without ATEX approval, with one or two sensor circuits, as well as with automatic, manual, and/or remote RESET. The devices are available in screw or spring-loaded technology (Push-In). There are versions with a width of 17.5 mm or 22.5 mm, for TH35 DIN rail or for screw mounting with an adapter, and with gold-plated contacts. Uniform accessories for all device variants, such as detachable terminals, plug-in tabs, and coding pins, simplify selection and inventory management. The 3RN2 thermistor motor protection relays replace the proven 3RN1 series. SIRIUS relays - a program for all cases.