Cause : Thermistor fault comes when thermistor circuit may become open, preventing the drive from accurately measuring the temperature.

"Thermistor fault" in "drive" indicate the drive detects an issue with its internal thermistor, which is used to monitor the temperature of the drive or motor. Thermistors are temperature-sensitive resistors that change their resistance with temperature changes, helping to protect the drive or motor from overheating.

Troubleshooting Steps for Thermistor Fault in Drives:

1. Check Fault Codes:

   • Review the fault codes on the drive’s display to confirm whether the issue is thermistor-related. Refer to the user manual to interpret the fault code and locate the thermistor for inspection.

2. Inspect Thermistor Wiring and Connections:

   • Ensure that all wiring and connections to the thermistor are secure. Check for loose or disconnected wires that might be causing intermittent faults.
   • If any connectors are loose or damaged, repair or replace them.

3. Test the Thermistor Resistance:

   • Using a multimeter, measure the thermistor’s resistance and compare it with the values specified in the Delta drive’s manual. If the resistance is outside the expected range, the thermistor may be faulty and require replacement.
   • Resistance should change as the temperature varies. If the resistance remains constant regardless of temperature, the thermistor may be faulty.

4. Inspect for Physical Damage:

   • Check the thermistor for any physical damage, such as cracks, burns, or signs of corrosion. If the thermistor is damaged, it will need to be replaced.

5. Test for Short or Open Circuits:

   • Use a multimeter to test for continuity in the thermistor circuit. A short circuit or open circuit will confirm that the thermistor has failed and must be replaced.

6. Verify Installation Location:

   • Ensure that the thermistor is installed in the correct location as per the manufacturer’s guidelines. If it’s placed too far from heat sources or in a location where airflow is restricted, it may provide inaccurate temperature readings.

7. Check for Overheating Issues:

   • Inspect the overall cooling system of the drive. Ensure that the fan is working properly and that the ventilation around the drive is adequate. If the drive is overheating, it could damage the thermistor.

8. Test the Drive’s Cooling System:

   • The thermistor is part of the drive’s thermal management system. Ensure that the drive’s cooling system, including fans and heat sinks, is operating effectively. If the cooling system is not functioning, it can lead to overheating and thermistor faults.