DJ Delorie wrote:

After all, you only have
one secondary winding on that transformer;

Actually, there are two secondary coils on the transformer, and they're
in series in this application. But there are other times when they are
in parallel. You can have a look at my website, and see some transformer
connections, including phase angles, that I had up for a discussion on
another NG. They are the most common three phase connections used today.

http://murrayranch.com/Electricity.htm


There is such a thing as two-phase power, where the hots are 90
degrees out of phase (three or four wire systems) but they're obsolete
these days.

There is also a 5 wire. On my web page you can see the Scott connections
that require special transformers to serve these obsolete loads from
modern three phase power. These are very rare today.


But those details don't matter for our purposes, I'm just being
pedantic.


So am I

Don