Spindle brake fuse blows intermittently

6 months ago the spindle would not stop. I found the regen resitor 10 amp brake fuse inside the inverter was blown. I replaced the fuse. I also found one of the inverter cooling fans was dead. I replaced both fans.

Then last month the fuse blew again. I replaced the fuse and both regen resistors and added an extra cooling fan beside the regen resistors.

Today the fuse blew again. I think there must be a problem with the inverter but I need someone to confirm this before spending $4000.00 , Thanks.

Before you spend the money for a new drive unit I would have the spindle motor meg'ed out. A failing motor can cause an overdraw. That could in turn cause premature drive failure.

Neal