On Monday, November 25, 2013 6:08:36 PM UTC-5, seamus wrote:
On 11/25/2013 05:25 PM, wrote:

Tell that to my lying scope. You put the two hot legs of the

split-phase service on a scope and what do you see?



How many phases does your oscilloscope show when you put the probe *reference clip* on L1 and the probe *tip* on L2?

(Mine shows a single-phase sin wave)



You're never going to see a phase difference looking at
just one waveform. There can only be a phase difference between
two or more waveforms. Hook the scope to L1, L2, with the
neutral as the reference point.





What is the peak to peak voltage when you put the probe *reference clip* on L1 and the probe *tip* on L2?



What is the RMS voltage when you put the probe *reference clip* on L1 and the probe *tip* on L2?







For whatever it's worth, my single-phase central air unit is powered only by L1, L2. The neutral is not used.

Which doesn't change the fact that you have two 120V legs which are
180 deg out of phase with each other.

Did you see reference to the IEEE paper, delivered at a power engineering
conference, that directly addresses the issue? Think the author is just a confused nut? Google "Kersting, W.H." and look at all the dozens of IEEE papers he's written if you have any doubts as to his credentials.

http://ieeexplore.ieee.org/xpl/artic...number=4520128

"Which now brings into focus the reality that standard 120/240 secondary systems are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. Further, the standard 120/240 secondary is different from the two phase primary system in that the secondary phases are separated by 180 degrees instead of three phases separated by 120 degrees. "