Re: Home shop power for a big machine - Thanks for the input

For what its worth, I have a 20hp Rotary Phase convertor, that I have
sucessfully run in my shop for nearly 2 years. Somedays, it runs 12-14
hours. It is a DESCO Phase convertor, and I use a Cutler Hammer 80 amp
switch to turn it on. I thought about just using the breaker at the
service panel, but decided that those were not intended to be everyday
switches. I can run my 7.5hp Bridgeport 412V Interact, Birmingham
J-head Mill (2HP), a metal band saw(1HP), as well as a State 24 inch
disc sander(2HP) without issue, all at once. I don't always do that,
but I have to test the Phase convertors mettle.
Those who chimed in about the initial draw at startup are correct, about
that being the biggest draw of current. As far as electrical costs,
even when I'm averaging 38-44 hours of run time a week, the added cost
to my electrical bill is maybe $80 per month, and that would be a high
guess. The cost of running it are so small, that I'm considering buying
a 3 phase lathe instead of 220v.

Best Regards,
Rob, MI

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@...> wrote:
>
> vrsculptor wrote:
> > I think this thread pretty well investigated what It would take to
run
> > a larger VMC in a home shop environment. There are other issues,
such
> > as the air requirements for a Fadal like machine, that we didn't
> > address but still need to be considered. For me, right now, the
> > negatives out weigh the positives.
> >
> What I would avoid like the plague are machines with a lot of
> hydraulics, like the Mazak they converted to EMC at Roland Freistad's
shop.
> It is a reliable machine, but if something in the hydraulics broke, it
> could get quite expensive to fix it. The machines with the simplest
> tool changers would be much more desirable. Anything with a "spindle
> drive" would be a plus, as opposed to something with just a massive
> 3-phase motor and a contactor. The Mazak mentioned above uses a huge
DC
> brush motor, probably would make a good traction motor for an electric
car!
>
> The Tree is well thought of, and I think they are of the simple=better
> sort. I know several people have done successful retrofits of them.
>
> Jon
>