Cause : External fan acknowledge missing comes when the drive has failed to receive a confirmation signal from an external fan, indicating that the fan is operating correctly.

F523 External fan acknowledge fault in ABB DCS800 drive indicates that the drive has detected an issue with the external cooling fan that is essential for maintaining proper operating temperatures.

Here’s how to troubleshoot and resolve this fault:

1. Check Fan Operation:

• Inspect the external fan to ensure it is running. Listen for operational sounds or observe the fan blades to confirm they are spinning.
• If the fan is not operating, check for power supply issues or faults in the fan itself.

2. Inspect Electrical Connections:

• Verify the electrical connections to the fan. Ensure that all wiring is secure and free of corrosion.
• Look for any signs of damage to the fan wiring, such as fraying or cuts, which may prevent proper operation.

3. Test Fan Voltage and Current:

• Use a multimeter to measure the voltage supplied to the fan. Ensure it matches the specifications provided by the manufacturer.
• Check the current draw of the fan while it is operating. If the current is outside the normal range, the fan may be failing or blocked.

4. Check for Obstructions:

• Inspect the fan and its housing for dust, dirt, or debris that could impede airflow. Clean the fan and ensure it is free of obstructions.
• Make sure there are no physical objects blocking the fan intake or exhaust, as this can affect cooling efficiency.

5. Monitor Operating Temperature:

• Keep an eye on the operating temperature of the drive. If the external fan is not functioning correctly, the drive may overheat, which can trigger the fault.
• Ensure that the environment around the drive is not excessively hot and that there is adequate ventilation.