Siemens 3UN2100-0AN7 PTC Thermistor Tripping Unit Auto Reset

Siemens 3UN2100-0AN7 is a PTC thermistor tripping unit with auto reset, designed to protect electric motors by monitoring winding temperature and interrupting the control circuit when overheating is detected, then resetting automatically when cooled. It operates on 220-240 V AC and supports 50/60 Hz, with a 1NO+1NC contact configuration and an IP20 enclosure suitable for panel mounting. The unit features two LEDs for status indication and enhanced interference suppression to improve reliability in demanding environments. In typical motor-protection setups, the 3UN2100-0AN7 provides one normally open and one normally closed output to trigger protection circuits and safeguard equipment from thermal damage.