Cause: Fan comes when cooling fan feedback missing. The drive monitors the fan's speed using a feedback signal. If this signal is not being sent correctly—even if the fan is physically spinning—the A581 warning will appear.

A581 warning in ABB ACS880 drive indicates a cooling fan issue. This means the drive cooling fan has either stopped spinning, is obstructed, or a feedback signal indicating its operation is missing.

Solution:

1. Check the fan blades for any physical obstructions, such as dust, debris, or foreign objects that may be preventing it from rotating.
2. Check the fan's power and signal connections. A loose or disconnected wire can cause the fan to stop and trigger the warning.
3. The fan motor or its internal electronics may have failed.
4. Replace fan then check same issue comes or not.