Auxiliary fan not running

What does 5081 mean?

An auxiliary fan fault has been detected; the auxiliary fan is not running. This compromises secondary cooling. The drive trips after a 2-minute suppression period during power-up, during which it only issues a warning. Continued operation without auxiliary cooling can lead to overheating.

• Auxiliary cooling fan motor has failed mechanically (e.g., seized bearings) or electrically (e.g., open winding).
• Control circuit for the auxiliary fan on the drive's PCB has failed, preventing power delivery to the fan.
• Wiring connection to the auxiliary fan unit is loose, broken, or has high resistance.
• Debris or foreign material has entered the auxiliary fan housing, physically obstructing its rotation.
• Auxiliary fan power supply (often DC) is absent or below the required operating voltage.

Click steps to track your progress.

1. 1

   1. Power down and visually inspect the auxiliary fan for obstructions, then gently attempt to manually rotate the blades to check for binding.

2. 2

   2. With power on (and observing safety precautions), confirm that the auxiliary fan is not spinning and there are no abnormal noises.

3. 3

   3. Measure the DC voltage supplied to the auxiliary fan connector (e.g., 24VDC) at the drive's control board output.

4. 4

   4. Test the continuity of the wiring harness connecting the auxiliary fan to the drive's control board.

5. 5

   5. Replace the auxiliary fan unit with an equivalent manufacturer-specified part to ensure correct functionality.