Harold and Susan Vordos wrote:

s
"Pete C." wrote in message
...
Harold and Susan Vordos wrote:
snip---



To the best of my knowledge, I chose the right service for my needs.
Considering I have nothing that is wired for 208, nor can any of it be
rewired to accommodate that voltage, I sure as hell didn't want it in
the
shop. If industry today is headed that direction, and machine tools
are
so wired, that's a whole different situation, and I'd have no quarrel
with
the choice. With the machines I have, that wasn't one of the options,
and
I sure as hell wasn't going to spring for transformers that weren't
necessary, not when all I had to do is request the right service.

It's likely that the potential issues diminish as the equipment gets
newer.

I certainly get that idea-----even PUD was somewhat surprised that I wanted
the delta service.


Stepping up for the one problem grinder makes sense, just as adding
boost transformers makes sense if it's only a machine or two that need
them.

I don't agree on the boost transformers, not when I'm as pleased as I am to
have the service I have. As I stated, I don't consider buying boost
transformers to be a bargain, nor would I like feeding them on a continual
basis, in spite of the fact that we pay only $.0445 kwh for our power. I
have yet to discover one thing about my service that displeases me, and I've
had 3 phase delta since 1967. One of us is nuts! :-)


Remember, I'm not biased against delta service, I'm biased against wild
leg delta service, two different things.

You keep saying that, as if there's other types. I've heard of a corner
grounded delta (but don't understand how it relates to voltage), but as far
as I know, they all have a wild leg if you shoot for 120V. Is there
something I don't know or understand? The moment you introduce the
neutral, seems to me you're bound to have only two phases that yield 120V
unless your wired wye.

A pure delta service does not have a neutral at all. There is no 120v on
it, only 240v phase to phase. The corner ground is strictly for safety
purposes to limit the relative voltage from any phase to ground. This
can make that phase look superficially like a neutral, but it is not.



Were I planning a new shop with the full list of equipment to be in it,
their specs, etc. I might well decide on a service configuration that
included delta service for the machines. I would just avoid a service
configuration that included a wild leg.

OK---fill me in, then. What type of service would it be? Strictly 240 V?
That's what I have now. I do *not* use my 3 phase for single phase
service*, although when I wire my mill permanently, I will have single phase
for the power feed and work light, but only there. I'll do that so I can
keep the wires away from the bottom of the machine. I have the box
overhead, almost directly over the motor on the mill. 12' ceiling. You
can do that when you have a 5 wire system. Everything else is strictly 3
wires, plus ground. Do you still have heartburn over my wiring?

*The same phases that constitute my A & C phases in the 3 phase panel feed
my single phase panel, although through separate lines and conduit, from the
pole. Want to see a pic?

How are you going to wire the mill? Separate conduit from each panel to
separate boxes overhead and separate drops to the mill head and the
light / power feed? Is the neutral present in your three phase panel so
you can do a single feed from there? You can't or at least shouldn't
(I'd have to look in the code book) combine circuits fed from separate
breakers in separate panels in a single conduit run to the mill.

For the mill I would likely feed it strictly three phase and locally
derive the 120v with a small transformer. Of course I got about a dozen
1 KVA 240/480 x 120/240 transformers for about $10 each brand new so
that biases the economics a bit.

Pete C.