Motor Temperature Sensor (TF) Trip

What does 31 mean?

This fault occurs when the temperature sensor (TF) in either drive 1 or drive 2 is triggered, indicating an overtemperature condition in the respective motor. Common causes include excessive motor load, high ambient temperatures, inadequate motor cooling, or a faulty sensor itself providing an incorrect reading. Operating a motor above its rated temperature severely shortens its lifespan, degrades winding insulation, and risks permanent motor damage, necessitating immediate attention.

• Sustained mechanical overload on the motor, causing its internal temperature to exceed the thermal sensor (TF) trip point.
• Blocked cooling fins on the motor, or impaired motor fan, significantly reducing heat dissipation from the motor housing.
• Incorrect motor thermal protection parameters (e.g., P308, P309) configured in the MOVIFIT unit for the connected motor.
• Faulty motor temperature sensor (e.g., PTC thermistor, PT100) or a break in its wiring back to the MOVIFIT unit.
• High ambient temperature in the motor's operating environment, reducing the effectiveness of motor cooling.

Click steps to track your progress.

1. 1

   Measure the motor winding resistance of all three phases and insulation resistance using a megohmmeter (500VDC) to check for internal motor faults.

2. 2

   Verify the integrity of the motor temperature sensor wiring (e.g., terminals X20:TF+/TF-) back to the MOVIFIT unit using a multimeter for continuity.

3. 3

   Check the motor's cooling fan for proper operation and ensure the motor's cooling fins are clear of dust, debris, and obstructions.

4. 4

   Review drive parameters P308 (motor thermal model time constant) and P309 (motor thermal limit) for drive 1, or P318/P319 for drive 2, comparing to motor nameplate data.

5. 5

   Reduce the mechanical load on the motor if it is operating continuously above its rated current specification.