> For what it's worth, the building I bought has two services installed when > it was built in 1921 - single phase 120/240 for lighting loads, and 240V > Delta for three phase loads.
I bet you have a fun electrical system :D > It's the even more obscure corner-grounded delta I love the reaction when a tech or plant electrician encounters corner-grounded delta for the first time. The meter says one phase is missing, yet everything is fine! Often coming off a backfed transformer turning 208Y into 480 delta, which also apparently blows some minds. I did once see what happens when a new guy connects the neutral on the Y primary side. Thanks, Jonathan