Surge Suppressors

[ptonsparky]

If it were me, I would be installing a Line Reactor on that drive if it doesn't already have one. A Line Reactor slows down the rate of rise of a fault and can allow the VFD's internal protection to react and act without destroying themselves in the process. People don't like to add them because of the added cost and space, I call them "cheap insurance" and after the first failure, I definitely would have added them.

This is a very decent White Paper on the subject put out by my local PoCo, PG&E. Good reading.

As always an excellent source of information. Just don't know how You guys remember all this stuff.