On 9/13/19 8:37 AM, trader_4 wrote:

A bunch cut.

Simple fact, the example Ralph provided is two phase power. And phase
is not limited to 90 deg, you can make it anything you want, just
rotate the second winding. Of course in physics and engineering, we
don't need to create it physically at all to analyze it, we can do
that on a piece of paper. We take two voltage sources:

120 Sine(wt)
120 Sine (wt+O) where O is 0 to 359

Connect them on a common return, we have three wires, the same thing as
Ralph's example. Set O=180, what you have is another version of Ralph's
two phase power, the same thing as 240/120 into your house, two voltage
sources, 180 deg out of phase with each other.

But isn't there a point where two phase ceases to exist and
becomes single
phase? Wouldn't that be the point where capacitors or a start winding
are needed to start motors? Practically speaking. That's what I was
trying to get around to earlier.

Someone you know really well wrote this at 8:19 am on 9/12.

"There are two phases internally when the cap is in the circuit.
That's why it's there, to give a phase shift.
We call the motor single phase, because they run off a single phase
circuit."