On 11/28/2013 12:32 PM, wrote:
On Thursday, November 28, 2013 11:38:40 AM UTC-5, bud-- wrote:
On 11/27/2013 6:35 PM, wrote:

Neither will the IEEE power engineers:

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

"Distribution engineers have treated the standard "singlephase" distribution transformer
connection as single phase because from the primary side of the transformer these connections
are single phase and in the case of standard rural distribution single phase line to ground.
However, with the advent of detailed circuit modeling we are beginning to see distribution
modeling and analysis being accomplished past the transformer to the secondary. 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."

Not obvious what the author has in mind in the minimal summary of his paper.

It's clear to me:

"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."

He's saying that in fact you have two phases and that's how
you have to analyze it.

He is proposing that you consider them 2 phases to analyze it.

And says that is a change from how "distribution engineers" view
split-phase.


He clearly says the standard way of looking at split-phase, 3-wire
supplies is they are single phase.


He didn't say that at all.

"Distribution engineers have treated the standard "singlephase"
distribution transformer connection as single phase because from the
primary side of the transformer these connections are single phase and
in the case of standard rural distribution single phase line to ground."

He is suggesting a change from that view.


Everyone here but you (that has
provided an opinion) agrees with that.

The author suggests a departure where the 2 hot wires are considered
separate phases for "modeling".

He did not say it's just for modeling.

It is not really clear what he is saying when all we have is a summary
of the paper.

But he says he is proposing a change from how split-phase is viewed by
"distribution engineers".

And for modeling, if you are looking at
the *currents* in the 3 wires, you have to consider them separate phases
because the currents will be 180 degrees out of phase only if the loads
are resistive. Not obvious what the author is saying beyond that.

So, how can you consider them separate phases if they are
really not separate phases?

The currents are not necessarily 180 degrees out of phase even though
the voltages are. That is not something new. I have analyzed currents in
a split phase system without considering the voltages are different
"phases".

The summary does not indicate if he is talking about more than that.


But, alas, I don't see where the author's suggestion has been accepted.

The paper confirms what the rest of us have been saying.


How about these white papers from electrical eqpt manufactuers that
clearly talk about two phases being present:

http://www.behlman.com/applications/AC%20basics.pdf

It is a way of referring to the wires. And a way that is consistent
through the piece with 3-phase diagrams.

A single 120V circuit has a "Phase A" wire? What is the point of that?


http://www.samlexamerica.com/support...Circuit s.pdf


Also uses "Hot Leg L1 and L2".


Find me a 2 phase panel.

Other opinions here all disagree with you. Some of us are involved in
power distribution.
Your IEEE paper agrees with us.
You can call it whatever you want to. IMHO calling the legs "phases"
adds to confusion.

But I don't really care.