"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

Phases A and C to neutral yield 120V, phase B to neutral yields
208V. Delta panels *do* (or can) have 120 volts. My shop is wired
three
phase delta and has 5 wires, four conductors ( A, B and C phase, plus
neutral) and one ground. One avoids using the B phase for 120V,
obviously.

You are now describing wild-leg delta, with one side centertapped
to ground. Not all delta service comes that way, I think.

Jim

Yep, that's it. I've always known to avoid using the center space on the
panel for power unless I was shooting for 240 volts. The panel looks a
little strange to see the occasional space unused, and it tips one off that
there is something unusual about the system. In my current shop, I have
two panels, one of which is strictly used for 3 phase. The other is wired
single phase only. I was put on a demand meter for three phase, so I
figured I'd restrict the panel solely for that use. The single phase panel
has a different meter.

I've had three phase delta wiring in three different locations in my years,
all of which were that way. The first one was an open delta with only two
transformers. At the castle we had three "pigs" on the pole, just as we
do here. I was told by Utah Power & Light, years ago, that the open delta
system works fine so long as you don't have any large motors to power,
which, at that time, I didn't. The largest was my compressor at 5 horse.

Harold