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+--- Thread: running a VFD off a Rotary Phase Converter (/thread-2909.html)
running a VFD off a Rotary Phase Converter - Pete O - 11-01-2015
Can anyone tell me if there is any likely problem with running a 415v 3-phase input VFD off the 415v output of my rotary phase converter?
Trying to come up with the best solution for my lathe, which is currently running (unsatisfactorily) a 415v 3ph motor off a 240v single-phase input, 240v 3ph output, VFD. Now that I have the 415v available via the transformer in the RPC, I'd like to feed it to the lathe. One option is to replace the 240v VFD with a 415v model and plug it straight into the RPC, the other option would be to restore all the lathe switchgear and wiring to the original 3-phase configuration and run it off the VFD that way. I'd much prefer the 415v VFD option but not sure if a VFD would be happy with the 'artificial' 3-phase.
RE: running a VFD off a Rotary Phase Converter - Hopefuldave - 11-01-2015
Hi Pete,
I haven't tried that, but I'm sure it'd be happier than my hacked VFD - my lathe can only run on 415v 3-phase, so VFD has the incoming AC rectifier modded to a voltage-doubler so it thinks it has 480V coming in instead of 240, and single-phase instead of the 3-phase it really wants so it puts more of a strain on the bus reservoir cap's - possibly the worst it could be expected to handle and hasn't died yet...
Your generated 3-phase will probably have one leg higher than the others, but not substantially enough to harm the rectifier or cap's, and all three phases will contribute to the VFD bus power, should be fine?