Cause: AI1 Thermal Sensor Error comes when the thermal sensor monitoring function has detected a thermal sensor error on analog input AI1 due to "open circuit" or "short circuit".

"t1CF" fault in Schneider ATV950 drive indicate "AI1 Thermal Sensor error". This means an issue with the thermal sensor connected to the AI1 analog input, which is typically used to monitor temperature. This error suggests that the drive is receiving an invalid or out-of-range signal from the thermal sensor.

Here is a structured approach to troubleshoot and resolve this issue:

1. Initial Checks:

• Restart the Drive: Power off the drive, wait for a few minutes, and then power it back on to reset any transient errors.

2. Check the Thermal Sensor:

• Sensor Integrity: Inspect the thermal sensor for any signs of physical damage or wear.
• Sensor Type: Verify that the sensor type matches the drive’s requirements (e.g., RTD, thermocouple, thermistor).
• Sensor Placement: Ensure that the thermal sensor is properly placed and in good contact with the surface it is monitoring.

3. Inspect Wiring and Connections:

• Cable Integrity: Check the wiring between the thermal sensor and the AI1 input for any signs of damage, wear, or loose connections. Replace any damaged cables.
• Secure Connections: Ensure that all connections are secure and properly seated. Loose or corroded connections can cause signal issues.

4. Verify Analog Input Configuration:

• Parameter Settings: Check the drive’s parameter settings related to the AI1 input. Ensure that parameters such as input type, scaling, and sensor range are correctly configured.
• Analog Input Range: Verify that the AI1 input range is set appropriately for the thermal sensor being used.

5. Test the Thermal Sensor:

• Measure Resistance/Voltage: Use a multimeter to measure the resistance (for RTD or thermistor) or voltage (for thermocouple) of the thermal sensor. Compare the readings with the expected values for the given temperature.
• Substitute Sensor: Temporarily replace the thermal sensor with a known good sensor to see if the fault clears. This helps determine if the issue is with the sensor or the drive.