[Dancy]

I have a large CNC mill that wants 3 phase 220 volts at 21 kw

anyone power somthing like this with a single to three phase variable frequency drive?

I can pick up a 20 kw on for around a thousand

[Jim Dawson]

For something that size you really want a rotary phase converter or maybe a solid state converter like a Phase Perfect. A VFD won't work to generate 3 phase to run the machine. And to operate a VFD on single phase, you need to upsize the VFD by at least about 1.7 or 2x. So something around 35-40 KW output.

Do you have enough single phase 240V power available? You're going to need around 100 amps or more to run that machine at full power.

[mactec54]

I have a large CNC mill that wants 3 phase 220 volts at 21 kw

anyone power somthing like this with a single to three phase variable frequency drive?

I can pick up a 20 kw on for around a thousand

You can't run anything other that a AC spindle motor with a VFD Drive, it can not be used to supply power to anything else, they don't output the same sinewave as normal power supply it would be great if they could everyone would be using them

Your only chance to run a machine that size is with a Phase Perfect first choice or a CNC rated Rotary Phase Converter RPC which is some case's is also not suitable for some CNC Machines

[atocom]

single phase to 3 phase converter is comfortable,