ABB · ACS880
The supply unit generates a warning when an earth fault or current unbalance is detected. This indicates a potential insulation issue within the supply unit's power circuit or its input cabling, requiring attention to prevent a full fault trip or damage.
Click steps to track your progress.
1. Disconnect the input power cables (L1, L2, L3) from the supply unit. Perform an insulation resistance test (Megger, e.g., 500VDC) on these cables to ground (PE).
2. Visually inspect the interior of the supply unit for signs of moisture, contamination, or carbon tracking, especially around the input terminals.
3. Verify that the PE (ground) connection to the supply unit's terminal block is tight and makes good contact.
4. If accessible and safe, measure the resistance of the input EMC filter components to ground for any unexpected low values.
5. Power cycle the entire system after ensuring all connections are secure and the environment inside the cabinet is clean and dry.