On Mon, 26 Jul 2004 04:53:58 GMT, "Ivan Vegvary" wrote:
My shop addition (21'x60' added on to an existing 40'x60') is coming along.
Had to let go of my electrician due to the fact that he never shows up etc.
He installed a new 3-phase service entrance. From said entrance we are
feeding a sub-panel to the old shop. This subpanel is single phase 100 amp.

I am to install a second 50 amp 3 phase sub-panel to another section of the
new shop. My question is wiring for the run to the sub-panel. I purchase
some 3-#6 wire (52' run). This is 3 #6's and a ground wire. 4 wires total.
Out of this 3-phase sub, I will be running circuits for my wife's kilns
(220v), my 3-phase machines and a few 20 amp (120v) plug circuits. I am
confused about the 120 volt circuits. Being that I only have 4 wires (3
current, one ground), how do I run a neutral wire to these circuits. Even
more confusing is that the neutral and the ground all run to the same bus
bar, so what is the difference?

If you have 3 ph delta 220, you will be able to supply 220 1 ph for the
kilns by connecting between any two hots, but there won't be any 120
volt to neutral (delta doesn't have a neutral, and the voltage from any
hot to ground won't be 120 volts).

If you have 3 ph wye, you can pull 120 from any hot to neutral, but you
won't have 220 1 ph for the kilns. You'll have 208 instead.

So the first thing you need to know is whether you have a delta or
wye feed.

Gary