Thermistor motor protection relays monitor the thermistors wound in motors. This helps prevent thermal motor overloads, e.g. due to high switching frequency, single-phasing, disabled cooling or excessive ambient temperatures. Up to 6 thermistors in series can be monitored. A conductor break in the sensor conductor will immediately trip the device. The device can also be used for monitoring wound quick-break switches - e.g. bimetal thermostats. This offers all-round motor protection.

• For the detection of
  • temperature limits being exceeded
  • wire breaks in sensor circuits
• 1 input for 1 to 6 thermistors
• With 2 LEDs green/red for ready-to-run and fault
• Response value: 3.2 to 3.8 k?
• Release value: 1.5 to 1.8 k?
• Max. cable length of sensor supply cable NYM 2 ? 1.5 is 100 m
• Remote Reset: over A1/A2 (NC contact) or over X1/X2 (NO contact)

LED displays:

• Green LED: lights up when operational voltage is applied
• Red LED: lights up in the event of overtemperatures or an interruption in the sensor circuit.