On Sat, 16 Nov 2013 14:54:22 -0600, sam E
wrote:

On 11/16/2013 10:34 AM, wrote:
On Sat, 16 Nov 2013 01:17:23 -0500, Wes Groleau
wrote:

On 11-15-2013, 19:58, wrote:
180 degrees, but technically, no. It's opposite sign, not 180 degrees
out of phase.

Same thing

No, it's not. It's one phase.


If the angle between the phases was anything other than 180, would you
call it 2 phase? If so, why this oddity?

Probably. Not sure what your question is, but 2-phase, where the two
are 90 degrees apart is interesting in that any phase relationship and
any number of phases can be generated with simple transformers and a
(very small) bit of trigonometry. It's quite useful but exceedingly
rare.

Two phases generated 180 degrees from each other make no sense at all.
It's no more efficient (less, actually) than single-phase and much
less efficient than three-phase. There are all sorts of other
alternatives, as well. Six-phase is somewhat interesting at times but
it's not as efficient as three phase. There's a reason the world uses
three.