Thanks for coming back so quickly

That very much marries with some other advice I've had and I'll certainly get down to test it but am resigned to a new VFD now, though keen to do those tests to make sure we don't blow it straight away

It's for a makerspace which doesn't have much money (pound in the pot) so I'll defintely come back to ask for suggestions for a VFD/ UK suppliers - very conscious of buy cheap buy twice as well.

Though, if running that one without water is a problem (if it's good) then I'll have to change that anyway and will look for something smaller

I'll test the resistances of the windings. May know where to borrow a megger and will report back once I've learned to use it

Thanks again. Can't tell you how helpful it is as out of my depth here.