Motor thermistor overtemperature

What does 11 mean?

The motor's thermistor temperature sensor or its connection is faulty or disconnected. This means the drive cannot accurately monitor the motor's temperature, risking undetected overheating. An unresolved thermistor fault could lead to severe motor damage due to thermal stress if the motor is indeed overheating.

• Open circuit in the motor thermistor wiring due to a loose connection at the motor terminal box or drive terminals (e.g., 53, 54).
• Damaged or broken thermistor cable conductor between the motor and the drive.
• Failure of the thermistor sensor itself (e.g., open, shorted, incorrect resistance value).
• Incorrect thermistor type or resistance range selected in drive parameters (e.g., P1-80 Thermistor Input, P1-81 Thermistor Trip Point).
• Faulty analog input for the thermistor on the drive's control card.

Click steps to track your progress.

1. 1

   Power off the drive and disconnect thermistor wires from drive terminals (e.g., 53, 54). Measure resistance across the thermistor wires at the motor terminal box.

2. 2

   Compare measured thermistor resistance to the motor manufacturer's specification at ambient temperature (e.g., NTC 1.5 kΩ at 25°C).

3. 3

   Check continuity of the thermistor feedback cable conductors from the motor terminal box to the drive terminals (e.g., 53, 54).

4. 4

   Inspect drive control terminals (e.g., 53, 54) for corrosion, damage, or loose wire connections.

5. 5

   Verify P1-80 (Thermistor Input) is set to the correct thermistor type (e.g., 'Pt100', 'NTC 1.5k ohm').