"K9SQG" wrote in message
...
Alan,

It has to do with efficiency, cost, complexity, etc. It was not a casual
decision. If one uses a delta configuration, instead of a Y, then you
only
need three leads, not four.


Unless you are tapping for 120 on a 240 Delta or 240 on a 480 Delta, in
which case a center tap of any of the phases becomes Neutral for a split
phase Edison circuit.