Fuse Blown

What does FU mean?

This fault indicates that an internal fuse in the inverter has blown, likely due to an overcurrent condition, a short circuit, or an internal component failure. A blown fuse often signifies a significant protective event and requires careful investigation before replacement. Operating with blown fuses can lead to further damage to the inverter's internal circuitry.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Before replacing any fuses, thoroughly investigate the cause of the fuse blowing (e.g., motor short, ground fault, internal component failure).

2. 4

   Perform insulation resistance tests on the motor and motor cabling to rule out external shorts.

3. 5

   If the cause is not external, internal inspection by a qualified technician or factory service may be required.