Re: [CAD_CAM_EDM_DRO] Captain Nema Nemo

You can run a 415V 3 phase motor on 240V single phase with a capacitor to
generate the extra phase. The reduced supply voltage will not affect the
speed but will reduce torque. If the motor windings are connected in star
(wye) then you may be able to reconnect them in delta and recover the most
of the lost torque.

I have been running my Brown and Sharpe mill in this way for a couple of
years now with no problems. The only real disadvantage is having to manually
switch the start capacitor out of the circuit when the motor has reached
running speed.

Les

> > What you want is a VFD (Variable Frequency Drive). With this, you will
> > not need the motor starter or the phase converter. 3 Phase motors are
> > usually cheaper than single phase, and also generally perform better.
>
> How much do VDF's cost in the 2-3hp range? The man said he couldn't

promise

> me the spindle motor works as he hasn't plugged the mill in yet. I thought
> it might be easier to renew the spindle motor anyway because it must have
> worn a bit by now. If it's triple phase I can start the spindle on my

single

> phase using the capacitor over two phases idea but 415V? Any thoughts? I
> could ask him to try it if he has triple 415v, whether he will or not I
> don't know.
>
> Thanks for the help,
> John He.
>