dpb wrote:

Stormin Mormon wrote:
How many amps, the breaker? For 20 amps, use 12 ga, for 30
amps, use 10 ga.

I've seen 2 conductor (with ground) wire used. I've also
seen 3 conductor used, so there is a neutral as well as a
ground.

Yes, the two poles of the 220 volt are out of time with each
other. Oddly, they call that single phase 220.

Well, they call it single phase because it is -- it's derived from two
taps from the same generation phase that are (as you say) lagged 180
degrees with respect to each other.

IOW, while the two are "out of phase" w/ each other, they are not
delivered from separate wires from the generator only two different
voltage taps. As an aside, three phase is separated by 120 degrees on
each phase so the difference in voltage between any two of them is
variable in time where as the two in single-phase 240V are mirror images
of each other and the voltage magnitude is fixed w/ time (sin^2 + cos^2
= constant).

Potentially (so to speak ) cornfoozing as there are two uses of the
word "phase", both of which are correct but refer to different
quantities/properties--the generator phases and the phase shift between
any two or three legs of the single- or three-phase power.

--

The two lines are indeed in phase with each other. They also are not
derived from different voltage taps, they are the connections to the
full 240V winding on the distribution transformer, the "neutral" is a
center tap in those windings. When looking at them relative to the
center tap neutral they will appear to be opposite polarity or 180 out
of phase.