On Oct 25, 12:58*pm, Karl Townsend
wrote:
"The Kid" is putting in underground wiring to his outbuildings. For
now, power will come from the house to the shop.

The shop sits twenty feet from a three phase line. future plans is to
install a three phase service to the shop, cut the ordinal transformer
out, and then feed one phase back to the house from the wiring being
installed now.

OK, a one phase house service has two 110 legs on the same phase
opposite polarity to get 220 across the two hot wires, neutral is the
center tap. As I understand it you in effect get three 110 hot wires
120 degrees apart in the phasing for three phase with the center tap
for neutral.

So, can you run single phase 220 off this? Need any special provisions
installed now? He's putting in conduit - four wires - two hot, neutral
and ground.

Karl

I have seen this done by using a Delta transformer with a center tap
that is grounded. Each hot side of grounded winding is 120 VAC and
220 VAC between them. This can lead to all sorts of issues when
hooking up 3 phase with internal 110 taps. the 3 phase is no longer
ballanced around ground. Lets just say some circute breakers got a
work out untill I figured it out.