Motor thermistor overtemperature

What does 11 mean?

The motor thermistor either indicates an overtemperature condition or has become disconnected. The drive can be configured to issue a warning or an alarm based on the setting in parameter 1-90 Motor Thermal Protection.

• Actual motor overtemperature condition detected by the thermistor due to mechanical overload or poor cooling.
• Open circuit or disconnection in the thermistor wiring between the motor and the drive's analog input (e.g., terminal 53/54).
• Faulty motor thermistor (e.g., NTC, PTC) providing an incorrect resistance value (e.g., infinite resistance for open circuit).
• Incorrect wiring connection to the drive's analog input, or incorrect terminal assignment for the thermistor.
• Drive's analog input (e.g., terminal 53/54) configured incorrectly (e.g., parameter 1-90 Motor Temp. Source not set to [2] Thermistor).

Click steps to track your progress.

1. 1

   Power down the drive, disconnect the thermistor wires from the drive's input terminals (e.g., 53/54).

2. 2

   Measure the resistance of the motor thermistor across its leads; compare to thermistor's temperature/resistance curve. An open circuit (infinite resistance) or short circuit (near zero resistance) indicates a fault.

3. 3

   Inspect the thermistor wiring for breaks, insulation damage, or loose connections along its entire length.

4. 4

   Verify parameter 1-90 (Motor Temp. Source) is set to [2] Thermistor and other thermistor-related parameters (e.g., 1-91 Trip Temp) are correctly configured.

5. 5

   Monitor motor current (e.g., P16-20) and motor temperature (e.g., with a thermal camera) to verify if the motor is actually overheating.