[hotrob1]

We have a Frenic FSD-25AR-22 that had 2 blown IGBT's, main fuse, a few diodes, etc. We repaired all this and it ran fine for approx. 50 hours or so.

The other day when braking, it blowed the IGBT's again, main fuse, and a couple of diodes. We repaired it again.

It started and ran fine at various RPM's. When we attempted to stop the spindle the same thing happened. It blowed the main fuse, the same two IGBT's, 1 transistor, and a few diodes.

Any thoughts? We are replacing the IGBT's with the same ones that we took out. (should be original part #)

We have also had the checked the cabling and megged the spindle motor.

Thank you.

[underthetire]

If i remember correctly, that drive used regen resistors. Large ceramic looking hot dogs usually on the outside of the machine under a vented cover. Check those.

[hotrob1]

Thank for the repsponse. I checked the (3) large green resistors. They checked good. I just finished cleaning and testing the magnetic contactor. It looked pretty pitted but looks/checks good now. I'm waiting for the IGBT's to get here. In the meantime, I'm going back trough the firing circuit as I find nothing else wrong with the braking circuit at this point. Any other info is appreciated.

Regards.

[hotrob1]

If i remember correctly, that drive used regen resistors. Large ceramic looking hot dogs usually on the outside of the machine under a vented cover. Check those.

I didn't remove the drive. Are you saying the drive may use external resistors for braking? It has 3 large green resistors in the top of the drive.

Regards.