200V 3phase motor - running on 415v

Hey all,

So Im trying to rebuilt a CNC lathe, all the motors are Fanuc motors, and run on 200v 3 phase power.

Since Im in Aus, only have access to 415.

Im trying to avoid using a 200v VSD, because I don't know where to buy them, and know nothing about them, on top of that, I work in controls and have access to wholesale VSD prices and lots of then

So...Ive got a Fanuc 8S 7.5kw spindle motor that needs a drive, can I take advantage of the voltage/frequency relations to run it off a 415v VSD? Has any one tried this before?

You can do it, but your motor will not likely last very long. The VFD will still have a DC bus voltage commensurate with your 415V input, so roughly 585VDC. That then means each and every pulse in the PWM sent to the motor will be 585V instead of the usual 282V that a 200V motor would be designed around, or even the 338vDC expected from a 240VAC input. Yes, the PWM can be modified to make the RMS voltage appear to be 200VAC, but it is the inductive aspect of the motor that averages out those little DC pulses, the pulses are always at the DC bus level and if those DC pulses are 2x the normal potential, that will stress the motor winding insulation and lead to an early demise. Just go get a 415/240V transformer and a 240V rated VFD, they are easy to find on line.