On 31 Dec 2003 00:48:51 GMT, K9SQG wrote:

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.

IIRC (it's been 50 years since I studied this) a Y-Y circuit
has problems with in-phase circulating third harmonic currents
flowing on the neutral.

--
73 de K2ASP - Phil Kane P.E.