Jess wrote:
Hi all,

I would like some help / advice in outfitting my shop.

For the first time in my metalworking home shop, I am able to get 3
phase service from the local power company.

In the past, I have always used a 3 phase rotary converter that I
built with the help of the group here - special thanks to Fitch and
Bob Campbell.

My question is, which voltage should I specify - and why?

I can get 208v, 220v or 440v.

What are the pros and cons, if any, between the choices?

My lights and shop equipment are all multi-tap wired and are capable
on running on any of the voltages.

I do have some small bench top and hand held machines that require
110v single phase.

I have one lathe powered by a 200v three phase motor - I would be
willing to replace this motor, if it would seem to be an advantage to
go with one of the higher voltages for other reasons.

I have hopes of going to some newer machinery in the future, most /
all of it seems to be rated for 220v, but with the notation that it is
operable on 208.

Your help and advice on this is greatly appreciated. Thanks in
advance,

Jess

I'm going to agree with the folks recommending against the 480v. That's
the evil power, everyone I've ever discussed it with agrees. Another
angle is that you need top quality stuff for 480, you just don't want to
use used wire and plugs on it, where with 240 you can use stuff that's
less than absolutely perfect. A little carbon tracking in a plug, it'll
arc with 480v where it just doesn't seem to with 240.

If you're willing to buy all new stuff, there's the natural gain of
lower amperage draw with 480.. but it'll find any problems in your
wiring, etc. far quicker than 240v. Motor insulation is no problem, the
windings only see 240v either way, it's the plugs and wiring that's the
issue.

John