Re: Three Phase Power

Jeff,

Whether a VFD can be reliably run off a rotary converter is a good
question. I never was able to get a straight answer to that when I
put a new spindle motor in my CNC lathe. So I dedided not to try
that combination.

I ended up feeding the machine from a large rotary converter with
the spindle running from a VFD using the 2 single phase legs.

The rotary converter output is still needed for the coolant pump and
the live tooling which operate at constant speed and are frequently
turned on/off under program control.

If I knew for sure whether the VFD could be run off the rotary I
might have saved a few bucks by not having to buy as large a VFD due
to it's single phase input derating.

Doug






--- In CAD_CAM_EDM_DRO@yahoogroups.com, "jeffalanp <xylotex@h...>"
<xylotex@h...> wrote:

> Hi All,
> Has anyone ever used a single phase to three phase rotary phase
> converter to power a variable frequency drive VFD(which itself

runs a

> three phase motor)? Is it a good/bad idea?
>
> Anything I should be aware of, plan or prepare for?
>
> Has anyone built their own such converter or have suggestions on
> this? (I've already read http://www.metalwebnews.com/howto/ph-

conv/ph-

> conv.html)
>
> Thanks,
> Jeff