What have you tested on the output side of the drive unit? A bad motor, possibly bad conductors or simply a loose connection could cause this. How long has this been going on? The first time that it happened did you find anything? If so, after replacing the IGBT module, did anyone verify the gate connections and all other connections to the drive? Lastly what type drive unit is it?
Unfortunately, this problem has been happening on many different systems. All these details have been thorowly checked by many experts. We have lost many dozens of SKiiPs IGBT modules over a 2 years period at a most of our sites. Semikron's experts came twice to take measurements. All they could say is that there are no external causes for the failures. They are stopping short from saying it is a design flaw in the SKiiP for obvious reasons. Semikron's management says that we are the only customer with this problem and refuse to take responsibility. I have good reasons to doubt we are the only ones. The part we are using is the SKiiP 603GD122-3DUW. I know that very few company use this water cooled module and I am trying to find them to find out if we really are the only ones.
