Need Help!- Can you use a VFD to run the spindle and power the cnc mill also?

[CATCH22]

Im wondering if it is possible to use a VFD to convert 1 phase to 3 phase, run the spindle and power the cnc mill servo motors,and everything else that needs to be powered in a cnc mill?

Thanks Mike

[Al_The_Man]

Not recommended off the same VFD, and you would have to run the VFD at 60hz constant, no spindle rpm control.
But in most cases the Servo's can be run off 1 phase unless this is a very old system with either a 3 phase supply to the servo drives or the drives are 3ph SCR bridge?
Al.

[CATCH22]

Yes thats right Al, the transformer for the servos has 240v single phase going into it. And there is another transformer that has 3 phase in and it comes out at 120v single phase. So I should be able to get away with just running 240v single phase in the panel and branch off of that to the vfd and then to the transformer,and just use one wire and the common for the 120v single phase,does this sound like it would be ok to do?

Thanks Mike

[Al_The_Man]

Many just run 240v 1ph into the panel and feed the VFD and split off to 240/120v transformer, or you can run a neutral for the control and servo's if you wish.
Don't forget to set up appropriate fusing for each particular circuits.
Al.

[CATCH22]

Thanks Al.

[mike_Kilroy]

Originally Posted by CATCH22 .........So I should be able to get away with just running 240v single phase in the panel and branch off of that to the vfd and then to the transforme............. Thanks Mike

Mike, any vfd typically used and discussed here will not work for this. they work great for running a 3 ph motor but will not run a 3ph xfmr and power other 3 ph equipment. the vfd will likely just immediately kick on on current errors and even if it does not, the square wave switched output would likely overheat the xfmr, and if it did not, the spikes would likely kill any electronics run off the secondary. I tried once for a few hours to power a simple 3ph 460v motor thru a 230v output vfd and never got out the gate due to instant and continuous drive faults. another time i did burn up a transformer pretty quickly due to the square wave output. we do apply and sell very expensive vfd drives that comfortably will do what you want, but the price is 10 times higher than what you are expecting. So this is not just theory or guesses