[ceencee]

My shop has only single phase power, all our big 3 phase equipment we run off a 20 HP rotary phase converter. I would like to build the cnc router controller to accept only single phase so i dont have to worry about the wild leg which i know is there some days....and bad. My cnc has 2 variable speed 5hp spindles, a non variable 3hp spindle and a 4hp 3 phase motor that drives the drill bank.
I am getting a VFD inverter for the variable speed spindles, but could i use the vfd for the non variable and use it just as a phase converter? Only one motor will be running at a time and i would set up a series of contactors controlled by the computer to switch them. Does this sound feasable or am i missing something?

[Al_The_Man]

I would only consider it if all the motors were the same type and configuration/rating.
You normally set the parameters up for one particular configuration of motor, so mix and matching them may cause you to run into a few different problems.
Even running two motors simultaneously off of one VFD, the motors should be the same and the rpm and load should not differ by more than 10% between each.
Going with a make like WEG, you can get free engineering advice on their product usage.
Al.