On Wed, 8 Aug 2018 06:37:21 -0700 (PDT), trader_4
wrote:

On Tuesday, August 7, 2018 at 7:29:05 PM UTC-4, Mark Lloyd wrote:
On 08/07/2018 01:27 PM, devnull wrote:

[snip]

The secondary winding is one continuous conductor with a tap fastened in
the middle.Â* But the tap is unused to provide 240 volts.Â* You could
remove the tap and sit on it and you would still have 240 volts single
phase.Â* Get it?

With a disconnected (or nonexistent) center tap, you'd have 240V single
phase. The difference from 2 different phases is that you changed the
point of reference.

Exactly. They try to treat the center tap as a mere curiosity, when it's
purpose is to create two 120V voltage sources that are 180 deg out of
phase with each other with respect to it. And it becomes the NEUTRAL,
the SYSTEM reference point. I've asked many times
for someone to draw a circuit diagram that models that circuit without
using two 120V voltage sources that are either 180 out of phase or of
opposite polarity, which is the same thing. They won't because it
can't be done.

I have posted it several times