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 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.


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.



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?





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

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

Are they wrong too?







My service panel is "single phase". If I replaced it, the only panels

manufacturers have are "single phase". The 2-pole breakers for them are

"single phase".



I propose we resolve this by using L1, in my L1-N-L2 service, as the

reference. L1-N and L1-L2 are in phase.



The standard real 2-phase supplies have 2 transformers 90 degrees apart

with the centertaps connected. Does this then have 4 phases?



In a 3-phase wye system are there 6 phases at the transformers (each

transformer has 2 ends)?

No because the logical reference point to look at phases
is from the neutral common point. You have 3 phases, differing by 120 degrees.
Similarly, the logical reference point in a split-phase service is
the neutral common point. From that perspective, you have two phases
present. Since you brought up 3 phase, what about the other thread
I started where I used 3 phase to show how you can get to split-phase
and how it looks like two phases? A lot of people looked at that post, but
no one wants to comment? Here it is again:


Let's start with a 3 phase wye power source. For anyone
not familiar, here's a diagram of it, it's fairly straightforward:

http://central-energy.com/AppNotes.html

It's the first diagram that shows a 3 phase wye power source.
Let's assign Phase A as the reference point and make it 0 deg.
Phase B is 120 deg off from Phase A. Phase C is 240 deg off from
Phase A. You can see those 3 waveforms on a 3 input scope,
one input attached to each phase, the scope reference point tied
to the neutral. I believe everyone here is in 100% agreement that you
have 3 phases present there. Let's put that power source inside a box
and I run those 4 wires out of the box, I have 3 phases.
For convenience, let's assign each of the 3 voltage sources in
the box to be 120V. So, we have 3 phases emerging from the box,
with 120V between any phase and neutral. All this I hope we
agree is still 3 phase.

OK, so now, lets just leave everything as it is, but only run
Phase A and B and the neutral out of the box. How many phases
do I have now? I would hope that you would agree that I have
two phases, Phase A at 0 deg, Phase B at 120 deg. Again, I can
see exactly that on a scope.

Now, lets change the source for phase B so it's at 90 deg. How many
phases do I have coming out of the box? My answer: two. Change B to
175 deg. How many phases do I have? My answer: two. Change
B to 185 deg, how many phases do I have? My answer: two.
Now change Phase B to 180 deg and how many phases do I have?
My answer: two.

And if I have two there, how exactly is what's coming out of
that box any different than the 3 wires coming into a split-phase
240/120V service? You have a neutral and two phases 180 deg
apart coming out of the box. Between Phase A and neutral you
have 120V. Between
Phase B and neutral you have 120V. Between phase A and Phase B
you have 240V. What's coming out of that box
is identical in every way to what's delivered with a 240/120V
split-phase service. If I hooked either the box or the 240/120V
split-phase service up to your house, there is absolutely
nothing different in terms of current flow, voltage, etc
that is going on at the panel. You could not tell the difference.

Another way of looking at it. I could replace the power source
in the box with a center-tap transformer that delivers 240/120V
split-phase and you could not tell the difference. The electrical
charecteristics on the 3 wires coming out would be EXACTLY the same.

My position is clear. The 180 deg phase relationship is just
one special case of the various possibilities. You can still
view it as two phases, treat it that way from an engineering
analysis basis, etc. The opposing view is apparently that
something magical happens at 180 deg, so that it can no longer
be referred to as 180 deg out of phase, it must only be called
"opposite" or some other imprecise non-engineering term. In fact,
no one who says I'm confused has yet given their definition of "phase",
though I've asked 10 times now. How can you even talk about
something, when no one will define it?

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.

After shuffling across the carpet in your slippers, a spark is created when
you touch a doorknob.

Following the flawed concept of "return" as a circuit concept, the spark
goes where? It travels thru a wooden door, it's hinges, the door frame,
building structure etc, to earth ground?

Or, is the spark injected into the human, from a resulting high ground
potential? Ground, (often mistakenly understood as having zero/no potential)
is lurking in doorknobs waiting to zap some unsuspecting doofus.

--
Cheers,
WB
..............


"Harold W." wrote in message
news
Wild_Bill scrit:

It is aburd to belive that power is returned thru many miles of
distribution
gear and back to the generation source, or that it's returned thru the
soil.

The guy gfretwell showed us a few amps of current heading directly into
the ground.

Where did those few amps come from, and where did they go?

On Friday, November 29, 2013 11:24:24 AM UTC-5, bud-- wrote:
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".



You can analyze them any way you want. It doesn't change what is there.



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



What more does he need to talk about:

"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."

It's as clear as can be. He doesn't say, that there really are
not two phases present, but we can pretend there are. He says the
*reality* is there are two phases.









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.



And a way that says you have two phases, Phase A and B, and that they
are 180 deg out of phase with each other.



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



We're not looking at just a single 120V circuit. We're looking at
a 3 wire circuit.







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





Also uses "Hot Leg L1 and L2".



Sure. I have no problem with that. But why skip the elephant in the room:

"The primary side of the Distribution Transformer is connected between Ground and one of the 2400V, 7.2 kV, 12.47 kV, 13.2 kV or 13.8 kV
phases of the utility company's 3-Phase Distribution Network. The secondary of the Distribution Transformer has a grounded center tap and is
wound in a manner that supplies two 120 VAC phases which are 180° out of phase with each other (Split Phases)

The center-tapped configuration of the secondary side of the Distribution Transformer provides following voltages to the Service Entrance Panel:
• 120 VAC between the Hot Leg L1 (Phase A, Red wire) and the grounded, center tapped Neutral (White wire). The oscilloscope trace of the
voltage waveform between the Hot Leg L1 and Neutral shows the voltage rising in the Positive direction at the start of the waveform
• 120 VAC between the Hot Leg L2 (Phase B, Black wire) and the grounded, center tapped Neutral (White wire). Please note that the
corresponding oscilloscope trace of the voltage waveform between the Hot Leg L2 and Neutral shows the voltage rising in the Negative
direction at the start of the waveform. This indicates that the two 120 VAC voltages are 180 degrees out of phase
• 240 VAC between the Hot Leg L1 (Phase A, Red wire) and the Hot Leg L2 (Phase B, Black wire)"






Find me a 2 phase panel.


What something is commonly called doesn't change physics or electrical
engineering. It's like saying because you call something Kleenex,
it isn't actually a piece of soft tissue paper.





Other opinions here all disagree with you.

That isn't true either. We had one poster describing how
transformers are used to create phases in farm pump applications
that agreed with me. I also believe nightcrawler said he agreed with me.





Some of us are involved in

power distribution.

Your IEEE paper agrees with us.

It agrees only with what it's been *called* by the power
industry and clearly says that while it's called single phase,
in reality you have two phases and that is how you need to
model it. That is what the paper is about.



You can call it whatever you want to. IMHO calling the legs "phases"

adds to confusion.



But I don't really care.

You must, because you're still posting. And I'm still waiting for
a answer to the simple question of your definition of the term "phase".
Why is it that despite me having asked 12 times now, not one of those
arguing against me can even define it? How can you talk about something
you won't define?

And why no response to my detailed example of going from 3 phase,
to two phases that then looks just like a split-phase service?
Here's another example. People here have brought up
the 100 year old two phase system where the phases were 90 deg
apart. OK, I'll play that game. So we have two phase wires, A
and B and a neutral. Phase B is 90 deg apart from Phase A. Everyone
here seems to agree that two phases are present, right?

So, now let's make phase B 120 deg apart. Still two phase? Let's
make it 280 deg apart. Still two phase? Let's make it 170 deg.
Still two phase? Let's make it 180 deg apart, still two phase?
And if it's suddenly no longer two phase, why not and by what definition
of the term "phase"? And if it is two phase, then it's also electrically
indistinguishable from split-phase 240/120 coming into your house
from the service. That is the reality and that is exactly what the IEEE
author is saying. A phase difference of 180 deg is just one special
case of a phase relationship.

bud-- wrote:

On 11/26/2013 3:28 PM, Michael A. Terrell wrote:

Wild_Bill wrote:

I don't see the earlier comment, but from the links and the search question,
I presume the conversation was about a circuit term referred to as "return".

A lot f folks are fixated on naming one power lead as "return", when there
is nothng related to any sort of "return" taking place in a circuit.

There are 2 conductors.. and one is a higher potential than the other.
That's all there is to it, but you'll probably never fnd ths statement in
any text book.

The power is disspated at the load, and there is nothing to return to any
other location.

I don't know where the fantasy of a return originated, but there is none iin
an electrical circuit.
Hydraulic circuit, yes, thre is generally always a return line.. for obvious
reasons.

The earth, meaning the planet, is not half of an electrical crcuit.. with
maybe one exception being lightning strikes.
Hills and terrain affect RF energy, and the ground/earth at the base of an
antenna is often imbedded with conductors to form a ground plane.

Electrical circuts deliver power to an appliance, tool, light bulb etc as
the two differing potentials, and the power is disspated as heat, light,
motion etc at the device beng powered.

It is aburd to belive that power is returned thru many miles of distribution
gear and back to the generation source, or that it's returned thru the soil.
Yet, the majorty of folks believe and continue to express/repeat this
concept.


Idiot. Read this:

http://en.wikipedia.org/wiki/Single-wire_earth_return


I think it was used in the early days of the REA.

Where has it been used in the US in the last 50 years.

I don't remember ever seeing transmission or distribution lines without
a neutral.


I haven't been in a rural enough area in years to even look for one.
The fact that it isn't common doesn't mean that it doesn't still exist.
Some farms were 20 miles from the nearest highway, on a private dirt or
clay road. They were electrified by either a co-op or the TVA and 20
miles of copper wire was expensive.



--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

dave wrote:

On 11/26/2013 01:28 PM, Michael A. Terrell wrote:


Idiot. Read this:

http://en.wikipedia.org/wiki/Single-wire_earth_return


"Many national electrical regulations (notably the U.S.) require a
metallic return line from the load to the generator. In these
jurisdictions, each SWER line must be approved by exception."


Yes, the ground resistance has to be low enough to prevent gradient
voltages from killing people or animals.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.