On Sat, 16 Nov 2013 15:28:26 -0600, Mark Lloyd
wrote:

On 11/16/2013 12:50 PM, wrote:

[snip]

How those waveforms are derived, what else you call
them in a particular application, doesn't change the
fact of what they are and their relationship to each
other. There are many ways that such voltage waveforms
could be generated. It doesn't change the fact that in
a 240V residential service the two hots are in fact
180 deg out of phase realtive to each other.


I think the people who are denying that it (residential 120/240) is
2-phase are considering the (1-phase) connection to the transformer
primary. You still have 2 phases inside.

No, that's wrong. You only have one phase. It is split into two
legs. Words mean things.

You could be using 2 120V transformers (primaries in parallel,
secondaries in series with ground between then), a generator with a
2-phase (180 deg apart) output, or even 2 120V (synchronized)
generators. You still have 2 phases.