On Thursday, July 26, 2018 at 7:36:35 PM UTC-4, wrote:
On Thu, 26 Jul 2018 08:58:52 -0500, Sam E
wrote:

On 07/25/2018 02:28 PM, Bubba wrote:
On 7/25/2018 1:25 PM, wrote:
I can't tell you in simple terms why a nectarine isn't a peach either
but they are not the same.
Did you see the term "split phase" in those panel manufacturer's
descriptions? I didn't. They had single phase and 3 phase. They didn't
say "2 phase" either since that is really a thing, having absolutely
NOTHING to do with 120/240.

The fact that the word "phase" applies to one system (that one with the
phases 90 degrees apart) doesn't mean it doesn't apply to another.

Simply choosing to call ungrounded conductors "phases" does not make
it so.

This came from 3 phase where each ungrounded conductor does
represent a phase. When you are in single phase, it doesn't.
People are simply trying to rationalize that when you take a single
phase 240v circuit and cut it in half, you now seem to have 2 phases.
If I walk half way up a ramp, it may look like 2 ramps, one going up
and one going down but it is still just one ramp.
Even when you gang together 2 or more sources, in series, once they
are connected, they are still just one, single phase system and when
you look at it end to end, it will just be one sine wave.

The problem here is you can't give a definition of phase. It's funny
that all the experts here can't define single phase, two phase, N phase
power and then explain how two phase at 90 deg is two phase, while at
180 it's suddenly not. Isn't that how science and engineering works?
We don't have gravity explained for apples, but a different explanation
when it comes to rocks. We have a general case and then the individual
cases, examples, flow from it.

I've asked before, suppose you took two phase and made
it 179 deg, would it still be two phase? How about at 181? And again, I'm
not talking about how things are called from history, I'm talking about
what's actually there and how it's analyzed, just like the power industry
engineer, who's presentation I referred you to. The only way I see to
rule out 180 from being two phase is to specifically do it by definition.
But so far, I don't see any definitions anywhere.

On Fri, 27 Jul 2018 07:36:48 -0700 (PDT), trader_4
wrote:

On Thursday, July 26, 2018 at 7:36:35 PM UTC-4, wrote:
On Thu, 26 Jul 2018 08:58:52 -0500, Sam E
wrote:

On 07/25/2018 02:28 PM, Bubba wrote:
On 7/25/2018 1:25 PM, wrote:
I can't tell you in simple terms why a nectarine isn't a peach either
but they are not the same.
Did you see the term "split phase" in those panel manufacturer's
descriptions? I didn't. They had single phase and 3 phase. They didn't
say "2 phase" either since that is really a thing, having absolutely
NOTHING to do with 120/240.

The fact that the word "phase" applies to one system (that one with the
phases 90 degrees apart) doesn't mean it doesn't apply to another.

Simply choosing to call ungrounded conductors "phases" does not make
it so.

This came from 3 phase where each ungrounded conductor does
represent a phase. When you are in single phase, it doesn't.
People are simply trying to rationalize that when you take a single
phase 240v circuit and cut it in half, you now seem to have 2 phases.
If I walk half way up a ramp, it may look like 2 ramps, one going up
and one going down but it is still just one ramp.
Even when you gang together 2 or more sources, in series, once they
are connected, they are still just one, single phase system and when
you look at it end to end, it will just be one sine wave.

The problem here is you can't give a definition of phase. It's funny
that all the experts here can't define single phase, two phase, N phase
power and then explain how two phase at 90 deg is two phase, while at
180 it's suddenly not. Isn't that how science and engineering works?
We don't have gravity explained for apples, but a different explanation
when it comes to rocks. We have a general case and then the individual
cases, examples, flow from it.

I've asked before, suppose you took two phase and made
it 179 deg, would it still be two phase? How about at 181? And again, I'm
not talking about how things are called from history, I'm talking about
what's actually there and how it's analyzed, just like the power industry
engineer, who's presentation I referred you to. The only way I see to
rule out 180 from being two phase is to specifically do it by definition.
But so far, I don't see any definitions anywhere.

I defined phase as in single, 2 or 3. You just chose to ignore it.

You found one obscure white paper from a guy who lives in a place that
does not even use center tapped services and he said "split phase" so
you think that is the proper term.
In another thread we did talk about split phase motors but they are
still operating on single phase.

Phase is one sine wave, measured from end to end of a source and it's
relationship to the other phases. In the US we have 1, 2 (very rare)
and 3. Center tapping those secondaries does not magically add another
phase.
Since 3 phase wye is tied at the center, I can certainly play with a
scope and show you 6 distinct sine waves. (Phase to phase x3 and line
to neutral x3)
I suppose you might call that 6 phase but you would be wrong.

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.




You found one obscure white paper from a guy who lives in a place that
does not even use center tapped services and he said "split phase" so
you think that is the proper term.

Canada doesn't use center tapped? Maybe Clare can enlighten us, but I
thought they did. At any rate, the company sells power conversion products
into the USA and he did a lot more than just call it split phase, he
went through an analyis of it and how there are two 180 deg phases
present.


But more importantly, did you not see the presentation at a US power
industry conference that I provided? It's right here in the good old
USA and it's a detailed analysis of
exactly what we're talking about by an IEEE Fellow with 40 years
experience.

Here it is again:


Here, I found the presentation I referred to. It was made by a power
system engineeing professor with a career going back to the 60's.
He consults on power system, the presentation was made at a
power engineering conference and it's published by the IEEE,
he's a Life Member of the IEEE. He last worked for Milsoft
Utility Solutions, that does consulting for power utilities. He doesn't
sound like a stupid guy or a homeowner.

https://ieeexplore.ieee.org/document/4520128/

Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those used to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.



You can read it here as a Word document:

https://www.researchgate.net/profile...condary-Models


It's crystal clear that he agrees with my analysis, but go ahead feel
free to disparage him as a homeowner idiot.




In another thread we did talk about split phase motors but they are
still operating on single phase.

I agree with that.

On Fri, 27 Jul 2018 12:45:40 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.

You look at a system from end to end, not any small segment.
This is a single phase system.


You found one obscure white paper from a guy who lives in a place that
does not even use center tapped services and he said "split phase" so
you think that is the proper term.

Canada doesn't use center tapped? Maybe Clare can enlighten us, but I
thought they did. At any rate, the company sells power conversion products
into the USA and he did a lot more than just call it split phase, he
went through an analyis of it and how there are two 180 deg phases
present.

I don't know how Canadians talk and Clare is quick to point out they
do not use the NEC.
We are talking about accepted nomenclature for US based electrical
professionals. They have a different name for non metallic cable too.

"Split Phase" is a type of motor, not an electrical distribution
method.

Go ahead and look like an unqualified homeowner if you want
but don't be shocked when electricians and inspectors start to just
roll their eyes and ignore you..

I am out.

On Friday, July 27, 2018 at 5:40:53 PM UTC-4, wrote:
On Fri, 27 Jul 2018 12:45:40 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.

You look at a system from end to end, not any small segment.
This is a single phase system.

Inability to answer the simple relevant questions a student would
ask a teacher noted.





You found one obscure white paper from a guy who lives in a place that
does not even use center tapped services and he said "split phase" so
you think that is the proper term.

Canada doesn't use center tapped? Maybe Clare can enlighten us, but I
thought they did. At any rate, the company sells power conversion products
into the USA and he did a lot more than just call it split phase, he
went through an analyis of it and how there are two 180 deg phases
present.

I don't know how Canadians talk and Clare is quick to point out they
do not use the NEC.
We are talking about accepted nomenclature for US based electrical
professionals. They have a different name for non metallic cable too.

The issue was you claimed the author of the white paper I cited lives
in a country that doesn't use center tapped transformers to provide
240/120, to try to discredit him and his explanation about phase,
split-phase, etc. So, apparently you conceded that Canada does use
center tap transformers too.

And no, we're not talking just about accepted nomenclature, we're talking
about how you analyze circuits and what's really there. I've said that
from my very first post here.





"Split Phase" is a type of motor, not an electrical distribution
method.

Go ahead and look like an unqualified homeowner if you want
but don't be shocked when electricians and inspectors start to just
roll their eyes and ignore you..

I am out.

And again, you just completely blew off the IEEE paper that I again
provided you with a link to. A paper written by a power engineer
with 40 years experience, presented at a power industry conference,
published by the IEEE. A paper that directly addresses exactly what
we're talking about.


Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those used to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.


And finally, I'd note I've given you and any other professionals here
the opportunity for several days now to give us your engineering definiton
of N phase power. No one can. Funny, it should be easy. Let me do
it for you:

N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

That covers it all. From single phase to an unlimited number of phases.
It's like the unified field theory being sought in physics, the holy grail,
only this one we have a complete definition and it's simple.

Single phase - covered
Two phase 90 - covered
Two phase 179 - covered
Two phase 181 - covered
Three phase - covered
Six phase - covered

Now, the only way the 240/120V service isn't two phase under that simple,
straightforward definition is if you explicitly put something in there
to rule it out. Science and engineering typically don't do that. We
have definitions or laws that fits all cases. Now from a historical perspective, from a "that's what it's always been called in the power industry perspective", it can be labeled whatever winds up being used, for whatever
reasons. It's like calling what you blow your nose with Kleenex or
tissues. It doesn't change the fact that it's a soft paper product made
from trees.

And if you have a better definition of N phase power, I'd be happy to
see it.

On Sat, 28 Jul 2018 07:50:14 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 5:40:53 PM UTC-4, wrote:
On Fri, 27 Jul 2018 12:45:40 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.

You look at a system from end to end, not any small segment.
This is a single phase system.

Inability to answer the simple relevant questions a student would
ask a teacher noted.

I answered the question several times. I just told you what
electricians and inspectors call the service you have in your house.
If you can't understand that and need some other rationalizations to
explain what you have, go for it.
I don't care anymore.

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]

On Saturday, July 28, 2018 at 11:32:53 AM UTC-4, wrote:
On Sat, 28 Jul 2018 07:50:14 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 5:40:53 PM UTC-4, wrote:
On Fri, 27 Jul 2018 12:45:40 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.

You look at a system from end to end, not any small segment.
This is a single phase system.

Inability to answer the simple relevant questions a student would
ask a teacher noted.

I answered the question several times. I just told you what
electricians and inspectors call the service you have in your house.
If you can't understand that and need some other rationalizations to
explain what you have, go for it.
I don't care anymore.

No, you have not answered the simple specific questions.

You say that what was called two phase power 100 years ago when it
existed, was in fact two phases. You said it was over 4 wires.
I accept that. So, here are the simple questions a student might
ask a teacher:

If it were on 3 wires instead of 4, with a shared neutral, would there
still be two phases there?

If yes, then how about if I change the phase angle to 179 degrees or
181 degrees, would there still be two phases?

If yes, then why if I change it to 180, are there no longer two phases?



What did you think of my definition of N phase power?

On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase. If you walk
half way up a ramp, did you suddenly make two ramps. After all isn't
one going up and the other going down, from where you stand? That is
all center tapping a single phase transformer is doing.

The problem with using one term for two things is it confuses a
process where we try to make it simpler. Confusion can be dangerous
where electricity is concerned. We try to be precise when we speak.

On Sat, 28 Jul 2018 09:52:57 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 11:32:53 AM UTC-4, wrote:
On Sat, 28 Jul 2018 07:50:14 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 5:40:53 PM UTC-4, wrote:
On Fri, 27 Jul 2018 12:45:40 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.

You look at a system from end to end, not any small segment.
This is a single phase system.

Inability to answer the simple relevant questions a student would
ask a teacher noted.

I answered the question several times. I just told you what
electricians and inspectors call the service you have in your house.
If you can't understand that and need some other rationalizations to
explain what you have, go for it.
I don't care anymore.

No, you have not answered the simple specific questions.

You say that what was called two phase power 100 years ago when it
existed, was in fact two phases. You said it was over 4 wires.
I accept that. So, here are the simple questions a student might
ask a teacher:

If it were on 3 wires instead of 4, with a shared neutral, would there
still be two phases there?

It is actually on 5 wires and there is a neutral there.
Two phase does still exist in some archaic industrial equipment in the
North east the last I heard.

If yes, then how about if I change the phase angle to 179 degrees or
181 degrees, would there still be two phases?

How did you get 181 degrees? If it comes from a separate system, yes
it would be 2 phase.

If yes, then why if I change it to 180, are there no longer two phases?

The problem is you did not change it to 180. You just sampled a
different place on the same single phase wine wave.


What did you think of my definition of N phase power?

There is 1, 2 or 3 phase power in the US distribution system. Nothing
else. I do understand you could have circuits operating at any number
of different phase relationships but that will be in the electronIC
world, not US power distribution. It is a different culture with words
that are used differently. (I have lived in both) That is why you can
find very well credentialed people who do not speak "electrician". I
bet they think a "city hub" is a bus station and a "hickey" is
something you don't want to see on your daughter's neck. ;-)

On Saturday, July 28, 2018 at 1:30:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase.


Yes you did, by using a center tap you now have two voltage sources
that are 180 deg out of phase. You're getting hung up on how something
is created. Electrons in three wires don't care how they were created,
what the source was. AGain, if you took the old 90 deg two phase,
that had two phases you say. If I made it 179 would that be two
phases? 181? Then why not 180?



If you walk
half way up a ramp, did you suddenly make two ramps. After all isn't
one going up and the other going down, from where you stand? That is
all center tapping a single phase transformer is doing.

The problem with using one term for two things is it confuses a
process where we try to make it simpler. Confusion can be dangerous
where electricity is concerned. We try to be precise when we speak.

AGain, I don't know how many times I have to say this. What it's called
does not change what's there. And I didn't say to call it two phase power.
Neither did the IEEE Power Engineering paper I cited. We are simply
saying that electrically that's what you really have and how you can
analyze it.

On Saturday, July 28, 2018 at 1:42:19 PM UTC-4, wrote:
On Sat, 28 Jul 2018 09:52:57 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 11:32:53 AM UTC-4, wrote:
On Sat, 28 Jul 2018 07:50:14 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 5:40:53 PM UTC-4, wrote:
On Fri, 27 Jul 2018 12:45:40 -0700 (PDT), trader_4
wrote:

On Friday, July 27, 2018 at 12:26:34 PM UTC-4, wrote:


I defined phase as in single, 2 or 3. You just chose to ignore it.

You gave a definition that is historical, not from an engineering
perspective and you didn't define anything more than 3. You would
think if it's so simple, someone could define it for N phases.
And then you refuse to answer the obvious questions
that even a student would ask a teacher. According to you, two
phase was 90 deg over four wires. OK, so, if it was over 3 wires, using
one shared neutral, would two phases still be present? Now I change
the phase to 179 degrees or 181 degrees, are there still two phases?
Yes? No?

Why then are there not two phases present when it;s 180? The answer
of course is that there still are two phases, it just becomes a less
interesting case.

You look at a system from end to end, not any small segment.
This is a single phase system.

Inability to answer the simple relevant questions a student would
ask a teacher noted.

I answered the question several times. I just told you what
electricians and inspectors call the service you have in your house.
If you can't understand that and need some other rationalizations to
explain what you have, go for it.
I don't care anymore.

No, you have not answered the simple specific questions.

You say that what was called two phase power 100 years ago when it
existed, was in fact two phases. You said it was over 4 wires.
I accept that. So, here are the simple questions a student might
ask a teacher:

If it were on 3 wires instead of 4, with a shared neutral, would there
still be two phases there?

It is actually on 5 wires and there is a neutral there.
Two phase does still exist in some archaic industrial equipment in the
North east the last I heard.

If yes, then how about if I change the phase angle to 179 degrees or
181 degrees, would there still be two phases?

How did you get 181 degrees?


Why does that matter? The electrons in the cable don't care if
the other phase at some deg of separation was generated from another
winding on the same shaft, another generator that you somehow managed
to keep in perfect synch, or via an entirely electronic method, eg
synthesize it electronically like you would with a UPS.


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

That simple engineering definition neatly covers it all, one, two, three,
N phase.



If it comes from a separate system, yes
it would be 2 phase.

Separate system? Where did that requirement come from? Three phase
AFAIK is generated from 3 windings on the same shaft, separated by 120 deg.
Do diesel 3 phase generators have 3 motors? What's does a "separate system"
even mean? They can't be really separate and be locked at a fixed phase separation.




If yes, then why if I change it to 180, are there no longer two phases?

The problem is you did not change it to 180. You just sampled a
different place on the same single phase wine wave.

Of course I'm changing it to 180. I take your old 90 deg two phase
generator that you say was two phase. I move the second winding from
90 to 179. I think you're saying that's still 179. So, now I shut it
off, rotate the one coil 1 more deg, it's at 180. I start it up again,
is there now just one phase simply because it's 180, not 179?







What did you think of my definition of N phase power?

There is 1, 2 or 3 phase power in the US distribution system. Nothing
else. I do understand you could have circuits operating at any number
of different phase relationships but that will be in the electronIC
world, not US power distribution.

Which doesn't change how electrons behave or how systems are analyzed.
What you choose to call it does not change what is really there. You
also seem to dismiss the existence of Electrical Engineering, which
is the field of expertise that includes power
engineering, it's everything that flows out of Maxwell's Equations,
from a generator to radio waves. That IEEE Fellow that wrote the paper
analyzing exactly what we're talking about that you continue to dismiss
is one of them.



It is a different culture with words
that are used differently. (I have lived in both) That is why you can
find very well credentialed people who do not speak "electrician". I
bet they think a "city hub" is a bus station and a "hickey" is
something you don't want to see on your daughter's neck. ;-)

I gave you my definition of N phase power that neatly covers it all,
from one phase to N phase. I'm still waiting for your general definition,
that covers and explains the differences, as opposed, to relying on
"that's what we call it as a definition". I said in the first post I
would not *call* our residential power 240/120 two phase. I don't see
anyone doing that either. But electrically that is what you have with
a center tapped transformer. It behaves as, looks like and is two
voltage sources that are 180 deg out of phase with each other that
share a neutral.

On Sat, 28 Jul 2018 12:59:38 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 1:30:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase.


Yes you did, by using a center tap you now have two voltage sources
that are 180 deg out of phase. You're getting hung up on how something
is created. Electrons in three wires don't care how they were created,
what the source was. AGain, if you took the old 90 deg two phase,
that had two phases you say. If I made it 179 would that be two
phases? 181? Then why not 180?


There is only one secondary winding and only one source.
It is only confused homeowners who have trouble understanding that.

The rest is gibberish

On Saturday, July 28, 2018 at 4:44:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 12:59:38 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 1:30:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase.


Yes you did, by using a center tap you now have two voltage sources
that are 180 deg out of phase. You're getting hung up on how something
is created. Electrons in three wires don't care how they were created,
what the source was. AGain, if you took the old 90 deg two phase,
that had two phases you say. If I made it 179 would that be two
phases? 181? Then why not 180?


There is only one secondary winding and only one source.

You sure can't model what's going on over that service with only
one voltage source. Describe the simple circuit schematic, using
ideal voltage sources, that you'd use to model it. I can give you
mine, it's exactly the circuit diagram shown in the IEEE paper
describing the analysis of what we're talking about, which is two
ideal voltage sources. You
take one 120V ideal voltage source and connect it's negative side to
the positive side of another 120V ideal voltage source. Explain how
to model it with a just a single ideal voltage source.




It is only confused homeowners who have trouble understanding that.

The rest is gibberish

A center tapped transformer essentially creates two coils with one
end connected together.
Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? If that is still
two phases, then it's electrically identical to what's coming into
the house from the center tapped transformer.

All those are simple, very obvious questions a student would ask
a teacher. Note that when you apply electrical engineering uniformly,
you don't wind up with bizarre unexplainable singularities. And again,
I don't care what most of the industry chooses to call it, that
evolved from a historical perspective and from their perspective that
what enters the house is derived from a single phase off of their
3 phases. I acknowledged that in my first post. It's like Kleenex
or tissue, then saying that because it's commonly called Kleenex,
it can't be also called tissue or more importantly described or
analyzed as a soft paper product made from trees. If I take one
phase from some power source and put it into an electronic
black box that has six phases coming out the other side, synthesized,
is there only one because there was only one coming in? If five of
them are at 90, 120, 150, 210, 240 would those be legitimate phases but
the one at 180 isn't? Don't phases have equal rights and treatment
under the laws of electricity?

On 07/28/2018 12:30 PM, wrote:

[snip]

The problem with using one term for two things is it confuses a
process where we try to make it simpler. Confusion can be dangerous
where electricity is concerned. We try to be precise when we speak.

It's normal to what things to be simpler, however reality doesn't always
cooperate. The word "phase" has a meaning and wanting things to be
simpler doesn't change that.

If 2 lines have the same voltage and same phase, connecting them will
have no effect. Now, I have access to line1 and line2 on a 240V
receptacle (10-30), so connecting them together should no nothing (I
really know enough not to try that).

On Sun, 29 Jul 2018 06:19:13 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 4:44:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 12:59:38 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 1:30:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase.


Yes you did, by using a center tap you now have two voltage sources
that are 180 deg out of phase. You're getting hung up on how something
is created. Electrons in three wires don't care how they were created,
what the source was. AGain, if you took the old 90 deg two phase,
that had two phases you say. If I made it 179 would that be two
phases? 181? Then why not 180?


There is only one secondary winding and only one source.

You sure can't model what's going on over that service with only
one voltage source. Describe the simple circuit schematic, using
ideal voltage sources, that you'd use to model it. I can give you
mine, it's exactly the circuit diagram shown in the IEEE paper
describing the analysis of what we're talking about, which is two
ideal voltage sources. You
take one 120V ideal voltage source and connect it's negative side to
the positive side of another 120V ideal voltage source. Explain how
to model it with a just a single ideal voltage source.




It is only confused homeowners who have trouble understanding that.

The rest is gibberish

A center tapped transformer essentially creates two coils with one
end connected together.
Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?

No

The windings are still in phase. If they were out of phase, like the
windings in a GFCI transformer the resulting line to line voltage
would be zero because they would buck each other.

As I am going to say for the last time, you look at a system from end
to end, not from halfway in between the ends.


As the Dos Equis guy says, "Stay dumb my friend".

On Sunday, July 29, 2018 at 12:00:56 PM UTC-4, wrote:
On Sun, 29 Jul 2018 06:19:13 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 4:44:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 12:59:38 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 1:30:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase.


Yes you did, by using a center tap you now have two voltage sources
that are 180 deg out of phase. You're getting hung up on how something
is created. Electrons in three wires don't care how they were created,
what the source was. AGain, if you took the old 90 deg two phase,
that had two phases you say. If I made it 179 would that be two
phases? 181? Then why not 180?


There is only one secondary winding and only one source.

You sure can't model what's going on over that service with only
one voltage source. Describe the simple circuit schematic, using
ideal voltage sources, that you'd use to model it. I can give you
mine, it's exactly the circuit diagram shown in the IEEE paper
describing the analysis of what we're talking about, which is two
ideal voltage sources. You
take one 120V ideal voltage source and connect it's negative side to
the positive side of another 120V ideal voltage source. Explain how
to model it with a just a single ideal voltage source.




It is only confused homeowners who have trouble understanding that.

The rest is gibberish

A center tapped transformer essentially creates two coils with one
end connected together.
Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?

No

The windings are still in phase. If they were out of phase, like the
windings in a GFCI transformer the resulting line to line voltage
would be zero because they would buck each other.

As I am going to say for the last time, you look at a system from end
to end, not from halfway in between the ends.


As the Dos Equis guy says, "Stay dumb my friend".


If I'm the one who's dumb, why is it that I'm the only one here who
can give you a simple, logical, straightforward definition of N phase
power? I asked, no one could even define it. I gave it to you:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

Following your logic that you have to analyze a whole system, then we can't
use electrical engineering tools to
analyze the output stage in an audio amplifier unless we know the whole
"system" from end to end. We can't identify phase relationships in a
part of a circuit, without going all the way back to the generator???

And I keep giving you the opportunity to go all the way back to the generator,
asking the simple questions a beginning elec engineering student or
even a high school student might ask a teacher. Questions you won't
answer, step by step, because you get cornered by the truth. I answer
all your questions.


Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there. As I said before, from an engineering perspective,
let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what drives it
for there to be 6 phases there? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?

The other poster raised another good point. If there are not two phases
present, then I should be able to take any two receptacles in a house
and parallel them. Fact is you can't, because they are 180 deg out
of PHASE with each other.

On Mon, 30 Jul 2018 09:56:25 -0700 (PDT), trader_4
wrote:

On Sunday, July 29, 2018 at 12:00:56 PM UTC-4, wrote:
On Sun, 29 Jul 2018 06:19:13 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 4:44:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 12:59:38 -0700 (PDT), trader_4
wrote:

On Saturday, July 28, 2018 at 1:30:42 PM UTC-4, wrote:
On Sat, 28 Jul 2018 11:34:32 -0500, Sam E
wrote:

On 07/27/2018 04:40 PM, wrote:

[snip]

"Split Phase" is a type of motor, not an electrical distribution
method.

Can't accept a phrase applying to more than one thing? "Split phase" is
where two phases are made from one (in other words, one is split into
two). Whether it happens in a motor or in a transformer doesn't change
the appropriateness of the phrase.

[snip]
The problem with that is you did not create another phase.


Yes you did, by using a center tap you now have two voltage sources
that are 180 deg out of phase. You're getting hung up on how something
is created. Electrons in three wires don't care how they were created,
what the source was. AGain, if you took the old 90 deg two phase,
that had two phases you say. If I made it 179 would that be two
phases? 181? Then why not 180?


There is only one secondary winding and only one source.

You sure can't model what's going on over that service with only
one voltage source. Describe the simple circuit schematic, using
ideal voltage sources, that you'd use to model it. I can give you
mine, it's exactly the circuit diagram shown in the IEEE paper
describing the analysis of what we're talking about, which is two
ideal voltage sources. You
take one 120V ideal voltage source and connect it's negative side to
the positive side of another 120V ideal voltage source. Explain how
to model it with a just a single ideal voltage source.




It is only confused homeowners who have trouble understanding that.

The rest is gibberish

A center tapped transformer essentially creates two coils with one
end connected together.
Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?

No

The windings are still in phase. If they were out of phase, like the
windings in a GFCI transformer the resulting line to line voltage
would be zero because they would buck each other.

As I am going to say for the last time, you look at a system from end
to end, not from halfway in between the ends.


As the Dos Equis guy says, "Stay dumb my friend".


If I'm the one who's dumb, why is it that I'm the only one here who
can give you a simple, logical, straightforward definition of N phase
power? I asked, no one could even define it. I gave it to you:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

Following your logic that you have to analyze a whole system, then we can't
use electrical engineering tools to
analyze the output stage in an audio amplifier unless we know the whole
"system" from end to end. We can't identify phase relationships in a
part of a circuit, without going all the way back to the generator???

And I keep giving you the opportunity to go all the way back to the generator,
asking the simple questions a beginning elec engineering student or
even a high school student might ask a teacher. Questions you won't
answer, step by step, because you get cornered by the truth. I answer
all your questions.


Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there. As I said before, from an engineering perspective,
let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what drives it
for there to be 6 phases there? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?

The other poster raised another good point. If there are not two phases
present, then I should be able to take any two receptacles in a house
and parallel them. Fact is you can't, because they are 180 deg out
of PHASE with each other.

They are NOT 180 degrees out of phase, If they were, the line to line
voltage would be zero. You are just looking at the 2 halves of a 240v
sine wave.
Draw a sine wave. look at the center point and you see what I mean.
It is one sine wave, about 168 P/P (120 RMS) and from the center point
each side is the compliment of the other but it is still one sine
wave.
Until you understand that you will remain confused.

To make the 2 sides of that transformer 180 degrees out of phase you
would need to wind it in the opposite direction and we know it is just
one winding.
Your generator scenario also would require that they both be in phase
so the voltage would add or the resulting end to end voltage would be
zero, even though both were putting out 120.

In fact the farther you take 2 windings out of phase, the lower the
line to line voltage will be, hence 208 on regular 120 degree put of
phase 3P wye. (Sq/Rt of 3).

The line to line of a 2 phase from the two 90 degrees out would be
around 168 (120* sq/rt 2)

On 7/30/2018 12:56 PM, tarder_4 wrote:
If it's 180 phase difference, then what? Is that still two phases?

Just to be clear, this argument started after someone referred to single phase service as 2-phase service.Â* If you call the power company and ask to have 180° 2-phase electric service installed, they'll tell you they only offer single and three
phase...though there might be some 90° 2-phase installations still in operation. Furthermore, if you connect a dual trace scope up a certain way, it will look like you have two phases.Â* While that's a nice parlor trick that might make a slow student
scratch their head, the truth is that there is only one phase on the transformer secondary.

But I do have one question, I understand the advantage of 120° 3-phase and 90° 2-phase for starting motors but what is the advantage of your 180° 2-phase over standard single phase 120/240 service?

On Monday, July 30, 2018 at 3:29:07 PM UTC-4, Single Phase wrote:
On 7/30/2018 12:56 PM, tarder_4 wrote:
If it's 180 phase difference, then what? Is that still two phases?

Just to be clear, this argument started after someone referred to single phase service as 2-phase service.Â* If you call the power company and ask to have 180° 2-phase electric service installed, they'll tell you they only offer single and three
phase...though there might be some 90° 2-phase installations still in operation. Furthermore, if you connect a dual trace scope up a certain way, it will look like you have two phases.Â* While that's a nice parlor trick that might make a slow student
scratch their head, the truth is that there is only one phase on the transformer secondary.


It's not a parlor trick. Are you going to tell this power industry engineer,
an electrical engineer with 40 years experience, a Life Fellow of the IEEE,
who presented the
below paper at an industry conference of his peers, that he's wrong too?
I don't see either you or Fretwell addressing it. He addresses exactly what we're talking about
and says that 240/120 HAS TO BE ANALYZED AS A TWO PHASES, because that is
exactly what it is. Then he proceeds to do exactly that in the paper.
I provided a link where you can see where he does exactly that, and works
through the math. He teaches electrical engineering.




Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those used to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.



I also note that I gave everyone here days to just define one phase, two phase,
N phase power. Not one of you "experts" could do it. I did, very simply:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

It fits:

one phase
two phase 90 deg
two pahse 179 deg
two phase 180 deg
three phase
five phase
N phase


And I note you can't answer the simple questions a student would ask a
teacher:

The old two phase power was 90 deg over four wires. If it was instead
two phases over 3 wires, a shared neutral, would there still be two phases
present?

If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?

The reason neither of you will address it is because you can't. There
is no rational explanation and it leaves you grasping for straws.

Or how about the other scenarios I gave Fretwell. You have a black box
that generates 5 sine waves coming out of it, one at 120 deg, one at 150,
one at 180, one at 210. Fretwell would have you
believe you need to analyze an entire system to be able to determine
how many phases there are. I say the fact that there are five power
sources coming out, defined by their phase differences is all we need
to know that there are 5 phases there. Where are you on that? Are
there five or not? And if there are 5, why does the one at 180 deg
count there, but not coming into a house?

If there are not two phases, then I should be able to parallel any
two 120V receptacles in the house. Can I do that? No, because some
are 180 deg out of PHASE with the others. Everthing is explained with
basic electricity 101. I have all the questions raised here covered
explained. And it all fits with the IEEE Fellow's paper, 100%.
You two are left grasping at straws with evolving explanations that
make no sense. And once again, neither of you will respond to the
simple questions in the scenarios I put forth. I address all of yours.

On Mon, 30 Jul 2018 13:06:50 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 3:29:07 PM UTC-4, Single Phase wrote:
On 7/30/2018 12:56 PM, tarder_4 wrote:
If it's 180 phase difference, then what? Is that still two phases?

Just to be clear, this argument started after someone referred to single phase service as 2-phase service.Â* If you call the power company and ask to have 180° 2-phase electric service installed, they'll tell you they only offer single and three
phase...though there might be some 90° 2-phase installations still in operation. Furthermore, if you connect a dual trace scope up a certain way, it will look like you have two phases.Â* While that's a nice parlor trick that might make a slow student
scratch their head, the truth is that there is only one phase on the transformer secondary.


It's not a parlor trick. Are you going to tell this power industry engineer,
an electrical engineer with 40 years experience, a Life Fellow of the IEEE,
who presented the
below paper at an industry conference of his peers, that he's wrong too?
I don't see either you or Fretwell addressing it. He addresses exactly what we're talking about
and says that 240/120 HAS TO BE ANALYZED AS A TWO PHASES, because that is
exactly what it is. Then he proceeds to do exactly that in the paper.
I provided a link where you can see where he does exactly that, and works
through the math. He teaches electrical engineering.




Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those
used
to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of
the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.



I also note that I gave everyone here days to just define one phase, two phase,
N phase power. Not one of you "experts" could do it. I did, very simply:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

It fits:

one phase
two phase 90 deg
two pahse 179 deg
two phase 180 deg
three phase
five phase
N phase


And I note you can't answer the simple questions a student would ask a
teacher:

The old two phase power was 90 deg over four wires. If it was instead
two phases over 3 wires, a shared neutral, would there still be two phases
present?

If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?

The reason neither of you will address it is because you can't. There
is no rational explanation and it leaves you grasping for straws.

Or how about the other scenarios I gave Fretwell. You have a black box
that generates 5 sine waves coming out of it, one at 120 deg, one at 150,
one at 180, one at 210. Fretwell would have you
believe you need to analyze an entire system to be able to determine
how many phases there are. I say the fact that there are five power
sources coming out, defined by their phase differences is all we need
to know that there are 5 phases there. Where are you on that? Are
there five or not? And if there are 5, why does the one at 180 deg
count there, but not coming into a house?

If there are not two phases, then I should be able to parallel any
two 120V receptacles in the house. Can I do that? No, because some
are 180 deg out of PHASE with the others. Everthing is explained with
basic electricity 101. I have all the questions raised here covered
explained. And it all fits with the IEEE Fellow's paper, 100%.
You two are left grasping at straws with evolving explanations that
make no sense. And once again, neither of you will respond to the
simple questions in the scenarios I put forth. I address all of yours.


All that shows is this guy spends too much time in theory and not
enough time in the real world.
There are plenty of well credentialed people who write gibberish.

It is not 2 phases, it is just one and the reason you can't parallel 2
phases is exactly because it is ONE phase. You are taking the second
half of the sine wave and trying to lay it down over the other side.

On Mon, 30 Jul 2018 13:06:50 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 3:29:07 PM UTC-4, Single Phase wrote:
On 7/30/2018 12:56 PM, tarder_4 wrote:
If it's 180 phase difference, then what? Is that still two phases?

Just to be clear, this argument started after someone referred to single phase service as 2-phase service.Â* If you call the power company and ask to have 180° 2-phase electric service installed, they'll tell you they only offer single and three
phase...though there might be some 90° 2-phase installations still in operation. Furthermore, if you connect a dual trace scope up a certain way, it will look like you have two phases.Â* While that's a nice parlor trick that might make a slow student
scratch their head, the truth is that there is only one phase on the transformer secondary.


It's not a parlor trick. Are you going to tell this power industry engineer,
an electrical engineer with 40 years experience, a Life Fellow of the IEEE,
who presented the
below paper at an industry conference of his peers, that he's wrong too?
I don't see either you or Fretwell addressing it. He addresses exactly what we're talking about
and says that 240/120 HAS TO BE ANALYZED AS A TWO PHASES, because that is
exactly what it is. Then he proceeds to do exactly that in the paper.
I provided a link where you can see where he does exactly that, and works
through the math. He teaches electrical engineering.




Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those
used
to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of
the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.



I also note that I gave everyone here days to just define one phase, two phase,
N phase power. Not one of you "experts" could do it. I did, very simply:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

It fits:

one phase
two phase 90 deg
two pahse 179 deg
two phase 180 deg
three phase
five phase
N phase


And I note you can't answer the simple questions a student would ask a
teacher:

The old two phase power was 90 deg over four wires. If it was instead
two phases over 3 wires, a shared neutral, would there still be two phases
present?

If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?

The reason neither of you will address it is because you can't. There
is no rational explanation and it leaves you grasping for straws.

Or how about the other scenarios I gave Fretwell. You have a black box
that generates 5 sine waves coming out of it, one at 120 deg, one at 150,
one at 180, one at 210. Fretwell would have you
believe you need to analyze an entire system to be able to determine
how many phases there are. I say the fact that there are five power
sources coming out, defined by their phase differences is all we need
to know that there are 5 phases there. Where are you on that? Are
there five or not? And if there are 5, why does the one at 180 deg
count there, but not coming into a house?

If there are not two phases, then I should be able to parallel any
two 120V receptacles in the house. Can I do that? No, because some
are 180 deg out of PHASE with the others. Everthing is explained with
basic electricity 101. I have all the questions raised here covered
explained. And it all fits with the IEEE Fellow's paper, 100%.
You two are left grasping at straws with evolving explanations that
make no sense. And once again, neither of you will respond to the
simple questions in the scenarios I put forth. I address all of yours.

The reason you can't parallel these two "in phase" sources is that it
is connected in series. You can't simultaneously connect anything in
series and parallel at the same time.
If you want to parallel those two circuits, all you have to do is
break the connection at the center tap, making 2 windings. Then you
can connect them in parallel. If it was truly 180 out of phase the
voltage would be zero but since they are in phase you would have 120v
with the ability to handle twice the current.

On 7/30/2018 2:38 PM, wrote:
[snip]
They are NOT 180 degrees out of phase, If they were, the line to line
voltage would be zero. You are just looking at the 2 halves of a 240v
sine wave.
Draw a sine wave. look at the center point and you see what I mean.
It is one sine wave, about 168 P/P (120 RMS) and from the center point
each side is the compliment of the other but it is still one sine
wave.
Until you understand that you will remain confused.

To make the 2 sides of that transformer 180 degrees out of phase you
would need to wind it in the opposite direction and we know it is just
one winding.
Your generator scenario also would require that they both be in phase
so the voltage would add or the resulting end to end voltage would be
zero, even though both were putting out 120.

In fact the farther you take 2 windings out of phase, the lower the
line to line voltage will be, hence 208 on regular 120 degree put of
phase 3P wye. (Sq/Rt of 3).

The line to line of a 2 phase from the two 90 degrees out would be
around 168 (120* sq/rt 2)

+1

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:


If I'm the one who's dumb, why is it that I'm the only one here who
can give you a simple, logical, straightforward definition of N phase
power? I asked, no one could even define it. I gave it to you:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

Following your logic that you have to analyze a whole system, then we can't
use electrical engineering tools to
analyze the output stage in an audio amplifier unless we know the whole
"system" from end to end. We can't identify phase relationships in a
part of a circuit, without going all the way back to the generator???

And I keep giving you the opportunity to go all the way back to the generator,
asking the simple questions a beginning elec engineering student or
even a high school student might ask a teacher. Questions you won't
answer, step by step, because you get cornered by the truth. I answer
all your questions.


Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there. As I said before, from an engineering perspective,
let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what drives it
for there to be 6 phases there? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?

The other poster raised another good point. If there are not two phases
present, then I should be able to take any two receptacles in a house
and parallel them. Fact is you can't, because they are 180 deg out
of PHASE with each other.

They are NOT 180 degrees out of phase, If they were, the line to line
voltage would be zero.

Wow, you really are confused. Two 120 volt AC sources that are 180 deg
out of phase sharing a common neutral produce 240V between them.




You are just looking at the 2 halves of a 240v
sine wave.
Draw a sine wave. look at the center point and you see what I mean.
It is one sine wave, about 168 P/P (120 RMS) and from the center point
each side is the compliment of the other but it is still one sine
wave.
Until you understand that you will remain confused.

I suppose the prof of electrical engineering, who presented to his peers
at a power industry conference is confused too. Funny, he's saying
EXACTLY what I said. And he goes through many pages of analysis of it
as two phases.

"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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those used to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary."



Why is it that if you're so smart and I;m the one confused that you can't
answer the simple questions I posed?



Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?

So I run that into a house as 240/120, how many phases now?

If phase is so simple and you understand it, why can't you answer those
questions?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there. As I said before, from an engineering perspective,
let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what power source
it uses? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?

The other poster raised another good point. If there are not two phases
present, then I should be able to take any two receptacles in a house
and parallel them. Fact is you can't, because they are 180 deg out
of PHASE with each other.






To make the 2 sides of that transformer 180 degrees out of phase you
would need to wind it in the opposite direction and we know it is just
one winding.

That would be two phases just the same as it is two phases by center
tapping the transformer. If we did it with a separate winding, how
would you tell from the house that it was one vs the other? You
can't. Because there are two phases either way.




Your generator scenario also would require that they both be in phase
so the voltage would add or the resulting end to end voltage would be
zero, even though both were putting out 120.

No idea what your talking about now. And again, why can't you answer
the simple questions one at a time? Go back to the step by step generator
example. You claimed you have to analyze a whole system. I gave you
one in that example, so answer the simple questions.


In fact the farther you take 2 windings out of phase, the lower the
line to line voltage will be, hence 208 on regular 120 degree put of
phase 3P wye. (Sq/Rt of 3).

The line to line of a 2 phase from the two 90 degrees out would be
around 168 (120* sq/rt 2)

Anything else irrelevant that you'd like to toss in to try to avoid
answering those simple questions in sequence?

On Monday, July 30, 2018 at 4:14:53 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:06:50 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 3:29:07 PM UTC-4, Single Phase wrote:
On 7/30/2018 12:56 PM, tarder_4 wrote:
If it's 180 phase difference, then what? Is that still two phases?

Just to be clear, this argument started after someone referred to single phase service as 2-phase service.Â* If you call the power company and ask to have 180° 2-phase electric service installed, they'll tell you they only offer single and three
phase...though there might be some 90° 2-phase installations still in operation. Furthermore, if you connect a dual trace scope up a certain way, it will look like you have two phases.Â* While that's a nice parlor trick that might make a slow student
scratch their head, the truth is that there is only one phase on the transformer secondary.


It's not a parlor trick. Are you going to tell this power industry engineer,
an electrical engineer with 40 years experience, a Life Fellow of the IEEE,
who presented the
below paper at an industry conference of his peers, that he's wrong too?
I don't see either you or Fretwell addressing it. He addresses exactly what we're talking about
and says that 240/120 HAS TO BE ANALYZED AS A TWO PHASES, because that is
exactly what it is. Then he proceeds to do exactly that in the paper.
I provided a link where you can see where he does exactly that, and works
through the math. He teaches electrical engineering.




Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those
used
to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of
the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.



I also note that I gave everyone here days to just define one phase, two phase,
N phase power. Not one of you "experts" could do it. I did, very simply:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

It fits:

one phase
two phase 90 deg
two pahse 179 deg
two phase 180 deg
three phase
five phase
N phase


And I note you can't answer the simple questions a student would ask a
teacher:

The old two phase power was 90 deg over four wires. If it was instead
two phases over 3 wires, a shared neutral, would there still be two phases
present?

If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?

The reason neither of you will address it is because you can't. There
is no rational explanation and it leaves you grasping for straws.

Or how about the other scenarios I gave Fretwell. You have a black box
that generates 5 sine waves coming out of it, one at 120 deg, one at 150,
one at 180, one at 210. Fretwell would have you
believe you need to analyze an entire system to be able to determine
how many phases there are. I say the fact that there are five power
sources coming out, defined by their phase differences is all we need
to know that there are 5 phases there. Where are you on that? Are
there five or not? And if there are 5, why does the one at 180 deg
count there, but not coming into a house?

If there are not two phases, then I should be able to parallel any
two 120V receptacles in the house. Can I do that? No, because some
are 180 deg out of PHASE with the others. Everthing is explained with
basic electricity 101. I have all the questions raised here covered
explained. And it all fits with the IEEE Fellow's paper, 100%.
You two are left grasping at straws with evolving explanations that
make no sense. And once again, neither of you will respond to the
simple questions in the scenarios I put forth. I address all of yours.


All that shows is this guy spends too much time in theory and not
enough time in the real world.
There are plenty of well credentialed people who write gibberish.

I see, so prof of elec engineering, who wrote a paper, presented it
to peers at a power industry conference, had it published by the IEEE,
has 40 years of experience, consults for utilities, writes "jibberish".
I bet he can define N phase power too.




It is not 2 phases, it is just one and the reason you can't parallel 2
phases is exactly because it is ONE phase. You are taking the second
half of the sine wave and trying to lay it down over the other side.


Do you realize how whacko what you just posted is? It's precisely because
the two hots in half the receptacles in a house are on opposite phases,
that explains why you can't parallel them. If I take two 9 volt batteries,
I can parallel them if I connect positive to positive. I get the capacity
of both batteries at 9 volts. If I take two batteries and
connect them positive to negative, then they are connected in OPPOSITE
POLARITY and they explode. Opposite polarity in the AC world IS THE SAME
THING AS 180 deg out of phase and it's why you can't randomly
try to parallel any two receptacles. If they were on the same hot, (phase)
coming from the panel, then you could parallel them.

On Mon, 30 Jul 2018 13:30:23 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:

One more time S L O W L Y

I have a transformer with two 120v secondaries. Assume the taps are A
& B on each.
If they are wound around the core in the same direction from A to B,
do you agree each would be in phase if they are measured A to B.
Now if I connect them in series A to B do you agree the current is
going in the same direction in both windings so they are still in
phase? You will see 240v from the A to B on each end.
If they were connected A to A in series they would be 180 degrees out
of phase the voltage would be zero.
In fact they have to be in phase to add. Otherwise they buck.

Now look at your pole pig outside your house and tell me which one it
most closely resembles.

You are confusing the halves of one sine wave with two sine waves.
I don't know what the professor has to rationalize to teach this
simple thing to the snowflakes in his class.

On 7/30/2018 4:06 PM, tarder_4 wrote:
If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?


Lets analyze the circuit.

Ignoring the voltage/current zero crossings and assuming a pure resistive load,

at any time t, the current on the secondary winding is either flowing from end L1 toward end L2 or end L2 toward end L1.

Also, at that same time t, the voltage is either rising or falling at all points along the entire length of the wire at the same rate.

The rise and fall of the voltage at L1 and L2 are in sync, obviously because there is only one phase on the single continuous piece of wire that forms the secondary coil.

The rise and fall on the secondary coil is in sync with the rise and fall on the primary coil.Â* Since the primary coil is single phase, so is the secondary.

Clearly single phase, anything else is a parlor trick.


Are you in marketing?Â* I ask because I don't see how your "180° 2-phase" has any useful advantage over standard residential single phase service?Â* Seems like pure marketing fluff.

On Monday, July 30, 2018 at 4:22:11 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:06:50 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 3:29:07 PM UTC-4, Single Phase wrote:
On 7/30/2018 12:56 PM, tarder_4 wrote:
If it's 180 phase difference, then what? Is that still two phases?

Just to be clear, this argument started after someone referred to single phase service as 2-phase service.Â* If you call the power company and ask to have 180° 2-phase electric service installed, they'll tell you they only offer single and three
phase...though there might be some 90° 2-phase installations still in operation. Furthermore, if you connect a dual trace scope up a certain way, it will look like you have two phases.Â* While that's a nice parlor trick that might make a slow student
scratch their head, the truth is that there is only one phase on the transformer secondary.


It's not a parlor trick. Are you going to tell this power industry engineer,
an electrical engineer with 40 years experience, a Life Fellow of the IEEE,
who presented the
below paper at an industry conference of his peers, that he's wrong too?
I don't see either you or Fretwell addressing it. He addresses exactly what we're talking about
and says that 240/120 HAS TO BE ANALYZED AS A TWO PHASES, because that is
exactly what it is. Then he proceeds to do exactly that in the paper.
I provided a link where you can see where he does exactly that, and works
through the math. He teaches electrical engineering.




Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those
used
to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA
W. H. Kersting (SM'64, F'89, Life Fellow 2003) was born in Santa Fe, NM. He received the BSEE degree from New Mexico State University, Las Cruces, and the MSEE degree from Illinois Institute of Technology. He joined the faculty at New Mexico State University in 1962 and served as Professor of Electrical Engineering and Director of
the Electric Utility Management Program until his retirement in 2002. He is currently a consultant for Milsoft Utility Solutions. He is also a partner in WH Power Consultants, Las Cruces, NM.



I also note that I gave everyone here days to just define one phase, two phase,
N phase power. Not one of you "experts" could do it. I did, very simply:


N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

It fits:

one phase
two phase 90 deg
two pahse 179 deg
two phase 180 deg
three phase
five phase
N phase


And I note you can't answer the simple questions a student would ask a
teacher:

The old two phase power was 90 deg over four wires. If it was instead
two phases over 3 wires, a shared neutral, would there still be two phases
present?

If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?

The reason neither of you will address it is because you can't. There
is no rational explanation and it leaves you grasping for straws.

Or how about the other scenarios I gave Fretwell. You have a black box
that generates 5 sine waves coming out of it, one at 120 deg, one at 150,
one at 180, one at 210. Fretwell would have you
believe you need to analyze an entire system to be able to determine
how many phases there are. I say the fact that there are five power
sources coming out, defined by their phase differences is all we need
to know that there are 5 phases there. Where are you on that? Are
there five or not? And if there are 5, why does the one at 180 deg
count there, but not coming into a house?

If there are not two phases, then I should be able to parallel any
two 120V receptacles in the house. Can I do that? No, because some
are 180 deg out of PHASE with the others. Everthing is explained with
basic electricity 101. I have all the questions raised here covered
explained. And it all fits with the IEEE Fellow's paper, 100%.
You two are left grasping at straws with evolving explanations that
make no sense. And once again, neither of you will respond to the
simple questions in the scenarios I put forth. I address all of yours.

The reason you can't parallel these two "in phase" sources is that it
is connected in series. You can't simultaneously connect anything in
series and parallel at the same time.

More bizarre wandering in the wilderness. All one needs to
know is that I have a box, coming out of it are two hots, each 120v,
one 180 deg out of phase with the other, with a shared neutral.
End of story. No series, parallel, doesn't matter if it was generated
from a generator with two coils, from a center tap transformer, or
purely synthesized electronically like a UPS would. That "box" is
what the supply coming into your house looks like. And the two hots,
120V each, shared neutral, 180 deg out of phase, completely describes
it.


And again, I note that you still refuse to answer the simple step by
step questions that a beginning student would ask a teacher. Questions
that go to the heart of the issue. I can answer them and have,
why can't you? Here it is again:

Problem #1:

You say the old 90 deg two phase was over 4 wires. If I instead put
it over three wires, with a shared neutral, would there still be two phases?

Put two 120V windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Isn't that still two phases?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there.

Problem #2

I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what drives it
for there to be 6 phases there? If the 180 phase doesn't count as
a phase, then why not? I can see all five on a scope. Does it matter
that the black box is driven by one phase, 3 phases, a transformer,
a generator or a battery?


If you want to parallel those two circuits, all you have to do is
break the connection at the center tap, making 2 windings. Then you
can connect them in parallel. If it was truly 180 out of phase the
voltage would be zero but since they are in phase you would have 120v
with the ability to handle twice the current.

I don't have to reconnect anything. What's going on inside the house
is completely explained by there being two phases present that are
each 120V, out of phase with each other by 180 deg. It's exactly
what the electrical engineering prof said and did in his multi-page
complex analysis of how to correctly model it. My definition of N
phase, phases, covers it all. It consistently addresses every case
we've gone through. And it's odd that I had to define it
for you pros, after giving you a couple days to come up with your
definition of N phase power. You still have no definition.

On Monday, July 30, 2018 at 5:13:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:30:23 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:

One more time S L O W L Y

I have a transformer with two 120v secondaries. Assume the taps are A
& B on each.
If they are wound around the core in the same direction from A to B,
do you agree each would be in phase if they are measured A to B.
Now if I connect them in series A to B do you agree the current is
going in the same direction in both windings so they are still in
phase? You will see 240v from the A to B on each end.
If they were connected A to A in series they would be 180 degrees out
of phase the voltage would be zero.
In fact they have to be in phase to add. Otherwise they buck.

Now look at your pole pig outside your house and tell me which one it
most closely resembles.

You are confusing the halves of one sine wave with two sine waves.
I don't know what the professor has to rationalize to teach this
simple thing to the snowflakes in his class.

Go ahead, keep disparaging the professor of electrical engineering
with 40 years of experience, who presented the paper I cited at
a power industry conference to his peers. I'm sure they are all
dumb snowflakes. Did you look at the math, where he did the analysis?
This coming from the guy who still can't give a definition of what
N phase power even means. I gave you two or three days, then I gave
you the simple definition that cover it all. One that doesn't rely
on transformers, generators, it's a complete, general definition.


You're hung up on transformers, components when it doesn't matter
how what's delivered over those 3 wires originates. As I've said many
times now, it could be from a center tapped transformer, a generator
with two windings sharing a neutral, or a black box with electronics
that synthesizes it electronically.



N Phase Power - A power delivery system that uses N related voltage sources,
that are periodic waveforms of the same frequency, differing only in
phase.

Where is your definition? How can you argue about what something is or
isn't when you can't give the definition?

And again I note that neither you nor your new sidekick will answer
the simple two problems I laid out, ones that any beginning elect
engineer who took his first course in circuits could easily answer.
Here they are again. I can keep posting them at least as long as you
can refuse to answer:


Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?

So I run that into a house as 240/120, how many phases now?

If phase is so simple and you understand it, why can't you answer those
questions?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there.


As I said before, from an engineering perspective,
let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what power source
it uses? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?



Here;s another way of looking at it. Let's say you're an engineering student.
I put you in a house with 240/120 service, give you whatever instruments
and test gear you want, tell you to analyze the 3 wire service. You
don't know where it's coming from, how it's generated. Describe it and
how you would model it.

I can give you my answer. You have two 120V 60 hz sinusoidal voltage
sources that are 180 deg out of phase with each other that share a
common neutral. And that's how you'd model it, you need TWO ideal
voltage sources that are 180 deg out of phase with each other.
Or of opposite polarity if you like, which is exactly the same thing.
Note that I didn't need to reference transformers, synthesizers,
generators, or how many phases came from the power company. It's
completely defined by the electrons coming and going on those 3 wires,
without regard to how or where they were generated.

On Monday, July 30, 2018 at 5:24:46 PM UTC-4, Uniphase wrote:
On 7/30/2018 4:06 PM, tarder_4 wrote:
If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?


Lets analyze the circuit.

Ignoring the voltage/current zero crossings and assuming a pure resistive load,

at any time t, the current on the secondary winding is either flowing from end L1 toward end L2 or end L2 toward end L1.

Also, at that same time t, the voltage is either rising or falling at all points along the entire length of the wire at the same rate.

The rise and fall of the voltage at L1 and L2 are in sync, obviously because there is only one phase on the single continuous piece of wire that forms the secondary coil.

The rise and fall on the secondary coil is in sync with the rise and fall on the primary coil.Â* Since the primary coil is single phase, so is the secondary.

Clearly single phase, anything else is a parlor trick.

Sure, but what happens when you center tap the secondary? You now have
essentially two windings that are connected together, creating two 120V
voltage sources that are of opposite polarity, which with a periodic
waveform is what? ..... 180 deg phase difference. That's how you get 240/120
over a shared neutral. You have two 120V sources that are 180 deg out
of phase.








Are you in marketing?Â* I ask because I don't see how your "180° 2-phase" has any useful advantage over standard residential single phase service?Â* Seems like pure marketing fluff.

Is the professor of electrical engineering who has 40 years experience
and consults for utilities, who presented his paper at a power industry
conference of his peers a marketing fluffer too? His paper directly
addresses exactly this and agrees 100%, with what I said, complete with
the mathematical analysis.

Note again that I answered your questions, why won;t you answer mine?

Define one phase, two phase, N phase power.




The 100 year old two phase power was with a 90 deg phase difference.

Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?

So I run that into a house as 240/120, how many phases now?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there.


Let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what power source
it uses? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?

The other poster raised another good point. If there are not two phases
present, then I should be able to take any two receptacles in a house
and parallel them. Fact is you can't, because about half are 180 deg out
of PHASE with each other.

On Mon, 30 Jul 2018 15:04:45 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 5:13:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:30:23 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:

One more time S L O W L Y

I have a transformer with two 120v secondaries. Assume the taps are A
& B on each.
If they are wound around the core in the same direction from A to B,
do you agree each would be in phase if they are measured A to B.
Now if I connect them in series A to B do you agree the current is
going in the same direction in both windings so they are still in
phase? You will see 240v from the A to B on each end.
If they were connected A to A in series they would be 180 degrees out
of phase the voltage would be zero.
In fact they have to be in phase to add. Otherwise they buck.

Now look at your pole pig outside your house and tell me which one it
most closely resembles.

You are confusing the halves of one sine wave with two sine waves.
I don't know what the professor has to rationalize to teach this
simple thing to the snowflakes in his class.

Go ahead, keep disparaging the professor of electrical engineering
with 40 years of experience, who presented the paper I cited at
a power industry conference to his peers. I'm sure they are all
dumb snowflakes. Did you look at the math, where he did the analysis?
This coming from the guy who still can't give a definition of what
N phase power even means. I gave you two or three days, then I gave
you the simple definition that cover it all. One that doesn't rely
on transformers, generators, it's a complete, general definition.


I am just disparaging his rationalization of a simple thing. The
transformer in front of your house is essentially 2 windings IN PHASE
that are connected together in series. The fact that they center tap
it and ground the center tap might give the impression that one
suddenly changed directions but it is simply not true.
Lets even make this simpler for you.
I have the exact same transformer and I move the ground to one end,
like you see in Europe. It is a single winding with one end 2xx volts
above ground. You will agree this is clearly single phase?
Now how does moving the grounds back to the center change the number
of phases present or change the current flow in the second half of the
transformer at all?
Making this 2 generators does not change a thing. If the 2 generators
are in phase, hooking them in series doubles the voltage end to end
but each one is still working exactly the same way. Grounding the
junctions between them may look like something changed measured from
the middle but nothing changed.
It is my ramp again. If you are at the top, it is a ramp down. If you
are at the bottom it is a ramp up but if you are in the middle it
looks like 2 ramps, one up and one down. It is still just one ramp.

On Mon, 30 Jul 2018 16:03:01 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 5:24:46 PM UTC-4, Uniphase wrote:
On 7/30/2018 4:06 PM, tarder_4 wrote:
If yes, then how about if the phase angle was changed to 179 deg, or
181 deg, would there still be two phases there?

How about 180 deg? Two phases, yes or no?

And if it's suddenly no, then why?


Lets analyze the circuit.

Ignoring the voltage/current zero crossings and assuming a pure resistive load,

at any time t, the current on the secondary winding is either flowing from end L1 toward end L2 or end L2 toward end L1.

Also, at that same time t, the voltage is either rising or falling at all points along the entire length of the wire at the same rate.

The rise and fall of the voltage at L1 and L2 are in sync, obviously because there is only one phase on the single continuous piece of wire that forms the secondary coil.

The rise and fall on the secondary coil is in sync with the rise and fall on the primary coil.Â* Since the primary coil is single phase, so is the secondary.

Clearly single phase, anything else is a parlor trick.

Sure, but what happens when you center tap the secondary? You now have
essentially two windings that are connected together, creating two 120V
voltage sources that are of opposite polarity, which with a periodic
waveform is what? ..... 180 deg phase difference. That's how you get 240/120
over a shared neutral. You have two 120V sources that are 180 deg out
of phase.

The current flow in those 2 secondaries is still flowing in the same
direction, at the same time.
Kirchoff's law says that.
They did not change phase. You just changed the place where you were
looking at them.
Again, look at a sine wave and lay it over both windings. The 0 point
will be at the center tap. One side will be up and one side down at
any given instant. It is still just one sine wave and just one phase.

In "N-phase" it will be required to have "N" different sine waves but
that is just a red herring in this discussion because we just have 1,
2 and 3. In each of those there is a sine wave displaced by 90 or 120
degrees.

On Mon, 30 Jul 2018 13:06:50 -0700 (PDT), trader_4
wrote:

Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those used
to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA

When I read that I see him say he is talking about "modeling" not
reality.
My suggestion is maybe his software model needs to be adjusted to more
closely reflect reality.
Would you be happier if I found a half dozen articles by credentialed
people who explain why this is single phase?
I have certainly been in quite a few CEU seminars given by
professionals who explain it in very precise terms not software
models.
Perhaps this is just too complicated for homeowners to grasp. That is
why we say "hire an electrician".

On Monday, July 30, 2018 at 7:06:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 15:04:45 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 5:13:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:30:23 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:

One more time S L O W L Y

I have a transformer with two 120v secondaries. Assume the taps are A
& B on each.
If they are wound around the core in the same direction from A to B,
do you agree each would be in phase if they are measured A to B.
Now if I connect them in series A to B do you agree the current is
going in the same direction in both windings so they are still in
phase? You will see 240v from the A to B on each end.
If they were connected A to A in series they would be 180 degrees out
of phase the voltage would be zero.
In fact they have to be in phase to add. Otherwise they buck.

Now look at your pole pig outside your house and tell me which one it
most closely resembles.

You are confusing the halves of one sine wave with two sine waves.
I don't know what the professor has to rationalize to teach this
simple thing to the snowflakes in his class.

Go ahead, keep disparaging the professor of electrical engineering
with 40 years of experience, who presented the paper I cited at
a power industry conference to his peers. I'm sure they are all
dumb snowflakes. Did you look at the math, where he did the analysis?
This coming from the guy who still can't give a definition of what
N phase power even means. I gave you two or three days, then I gave
you the simple definition that cover it all. One that doesn't rely
on transformers, generators, it's a complete, general definition.


I am just disparaging his rationalization of a simple thing.

If you look at his paper, he's not rationalizing anything. He's
doing a very detailed and complex analysis of how loads on the 240/120
service affect the voltage that customers receive. He starts off
by explaining that what you really have are two phases there, that's
how you have to model it and that's how it has to be analyzed.
Then he analyzes it.



The
transformer in front of your house is essentially 2 windings IN PHASE
that are connected together in series. The fact that they center tap
it and ground the center tap might give the impression that one
suddenly changed directions but it is simply not true.

The center tap creates two voltage sources, with potentially two
differing currents flowing in them, of opposite polarity. What is another
way of saying two voltage sources are opposite polarity when they are
related periodic waveforms of the same frequency? You say that one is
180 deg out of PHASE with respect to the other.



Lets even make this simpler for you.
I have the exact same transformer and I move the ground to one end,
like you see in Europe.

IDK why you keep going back to transformers, when it's IRRELEVANT how
power is actually generated. I've said a dozen times now you could
generate 240/120 going into a house from a generator with two coils,
a transformer, or by synthesizing it totally electronically, or from
an imaginary black box, It does not change what is there, how the
currents flow, how the electrons behave.




It is a single winding with one end 2xx volts
above ground. You will agree this is clearly single phase?
Now how does moving the grounds back to the center change the number
of phases present or change the current flow in the second half of the
transformer at all?

Because now the two ends of the transformer are 180 deg out of phase
with respect to your new center tap, that's how. Call it opposite
polarity if you like. In electrical engineering, if you have two
periodic voltage sources, one is the opposite polarity of the other,
what do you call it? You say that one source is 180 deg out of
phase from the other.


Making this 2 generators does not change a thing. If the 2 generators
are in phase, hooking them in series doubles the voltage end to end
but each one is still working exactly the same way. Grounding the
junctions between them may look like something changed measured from
the middle but nothing changed.
It is my ramp again. If you are at the top, it is a ramp down. If you
are at the bottom it is a ramp up but if you are in the middle it
looks like 2 ramps, one up and one down. It is still just one ramp.


Why won't you just go through the simple questions, one at a time for
the two problems I presented:


Problem #1:

You say the old 90 deg two phase was over 4 wires. If I instead put
it over three wires, with a shared neutral, would there still be two phases?
(my answer YES)

Put two 120V windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?
(my answer YES)

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?
(my answer YES)

If it's 180 phase difference, then what? Isn't that still two phases?
(YES)

And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there.


Problem #2

I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what drives it
for there to be 6 phases there?
(NO)

Does it matter if it came from a
transformer, a generator or was synthesized using a battery?
(NO)

If the 180 phase doesn't count as
a phase, then why not? I can see all five on a scope.
(NO)

All that is very basic stuff.

On Monday, July 30, 2018 at 7:38:44 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:06:50 -0700 (PDT), trader_4
wrote:

Abstract:
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. What all of this means is that analysis software and methods must now deal with an electrical system requiring a different set of algorithms than those used
to model and analyze the primary system. This paper will describe the modeling and analysis of the single-phase center tap transformer serving 120 Volt and 240 Volt single-phase loads from a three-wire secondary.

W. H. Kersting
Milsoft Utility Solutions, USA

When I read that I see him say he is talking about "modeling" not
reality.
My suggestion is maybe his software model needs to be adjusted to more
closely reflect reality.

Good grief. It's not an issue of software modeling. It's an issue of
what the circuit really is, how it really behaves. From a circuit
standpoint, you don't need to know if it came from a transformer or
if it came from a synthesized electronically generated source from
a battery. The 240/120 service looks like TWO ideal voltage sources,
that are 180 deg out of phase or equivalently, of opposite polarity
sharing a common neutral. There is no other way to model it. That's
all he's doing. That's what everybody does, because that's what it
is, what it behaves like. If you feel otherwise, show us your alternate
model.


Would you be happier if I found a half dozen articles by credentialed
people who explain why this is single phase?
I have certainly been in quite a few CEU seminars given by
professionals who explain it in very precise terms not software
models.
Perhaps this is just too complicated for homeowners to grasp. That is
why we say "hire an electrician".

Back to the disparaging remarks I see. And still no answers to the very
simple questions a student would ask a teacher:


Define one phase, two phase, N phase power.

The 100 year old two phase power was with a 90 deg phase difference.

Put two windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?

Would there still be two phases there if I rotate one generator coil
so that it's 179 deg phase difference instead of 90?

Yes or no?


If it's 180 phase difference, then what? Is that still two phases?

So I run that into a house as 240/120, how many phases now?


And if that is still two phases, then it's electrically identical to
what's coming into the house from the center tapped transformer.
Electrons and engineering don't care how it was created, only what is
actually there.


Let's say I have a black box that has five phases coming out of it, at 120,
150, 180, 210, 240. They are electronically synthesized as you would in
a uninterruptable power supply. Do you need to know what power source
it uses? Why does it matter if it's powered
by a DC battery, single phase or 3 phase? Is the 180 one not a legitimate
phase, just because it's at 180?

The other poster raised another good point. If there are not two phases
present, if they are not of opposite polarity, then I should be able to
take any two receptacles in a house and parallel them. Instead with
some combos I get 240V? Two 120V circuits with voltage waveforms that are
out of phase by 180 with a shared neutral gives you exactly that.

On Mon, 30 Jul 2018 16:54:02 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 7:06:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 15:04:45 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 5:13:07 PM UTC-4, wrote:
On Mon, 30 Jul 2018 13:30:23 -0700 (PDT), trader_4
wrote:

On Monday, July 30, 2018 at 2:37:58 PM UTC-4, wrote:

One more time S L O W L Y

I have a transformer with two 120v secondaries. Assume the taps are A
& B on each.
If they are wound around the core in the same direction from A to B,
do you agree each would be in phase if they are measured A to B.
Now if I connect them in series A to B do you agree the current is
going in the same direction in both windings so they are still in
phase? You will see 240v from the A to B on each end.
If they were connected A to A in series they would be 180 degrees out
of phase the voltage would be zero.
In fact they have to be in phase to add. Otherwise they buck.

Now look at your pole pig outside your house and tell me which one it
most closely resembles.

You are confusing the halves of one sine wave with two sine waves.
I don't know what the professor has to rationalize to teach this
simple thing to the snowflakes in his class.

Go ahead, keep disparaging the professor of electrical engineering
with 40 years of experience, who presented the paper I cited at
a power industry conference to his peers. I'm sure they are all
dumb snowflakes. Did you look at the math, where he did the analysis?
This coming from the guy who still can't give a definition of what
N phase power even means. I gave you two or three days, then I gave
you the simple definition that cover it all. One that doesn't rely
on transformers, generators, it's a complete, general definition.


I am just disparaging his rationalization of a simple thing.

If you look at his paper, he's not rationalizing anything. He's
doing a very detailed and complex analysis of how loads on the 240/120
service affect the voltage that customers receive. He starts off
by explaining that what you really have are two phases there, that's
how you have to model it and that's how it has to be analyzed.
Then he analyzes it.

It sounds like a software bug in his model that he is rationalizing.


The
transformer in front of your house is essentially 2 windings IN PHASE
that are connected together in series. The fact that they center tap
it and ground the center tap might give the impression that one
suddenly changed directions but it is simply not true.

The center tap creates two voltage sources, with potentially two
differing currents flowing in them, of opposite polarity. What is another
way of saying two voltage sources are opposite polarity when they are
related periodic waveforms of the same frequency? You say that one is
180 deg out of PHASE with respect to the other.

Horse ****, It is still just one voltage source and the current is
flowing the same way in each of them at any given instant.
You are just looking at it from the middle so you get the illusion it
is 2 sources. If the tap was 2/3ds the way along the secondary, would
you say they were now 239 degrees out of phase?


Lets even make this simpler for you.
I have the exact same transformer and I move the ground to one end,
like you see in Europe.

IDK why you keep going back to transformers, when it's IRRELEVANT how
power is actually generated. I've said a dozen times now you could
generate 240/120 going into a house from a generator with two coils,
a transformer, or by synthesizing it totally electronically, or from
an imaginary black box, It does not change what is there, how the
currents flow, how the electrons behave.

The electrons are still moving in the same direction at the same
amperage on either side of that center tap. Kirchoff says that. The
only thing that differs is how much of the unbalanced load goes down
the neutral but it still adds up to what goes in each end. That is why
the utility only needs to measure the ungrounded leads.


It is a single winding with one end 2xx volts
above ground. You will agree this is clearly single phase?
Now how does moving the grounds back to the center change the number
of phases present or change the current flow in the second half of the
transformer at all?

Because now the two ends of the transformer are 180 deg out of phase
with respect to your new center tap, that's how. Call it opposite
polarity if you like. In electrical engineering, if you have two
periodic voltage sources, one is the opposite polarity of the other,
what do you call it? You say that one source is 180 deg out of
phase from the other.

If you divide a sine wave in half, it is always going to be opposite
polarity on each side of the divide but it is still just one sine
wave.

Making this 2 generators does not change a thing. If the 2 generators
are in phase, hooking them in series doubles the voltage end to end
but each one is still working exactly the same way. Grounding the
junctions between them may look like something changed measured from
the middle but nothing changed.
It is my ramp again. If you are at the top, it is a ramp down. If you
are at the bottom it is a ramp up but if you are in the middle it
looks like 2 ramps, one up and one down. It is still just one ramp.


Why won't you just go through the simple questions, one at a time for
the two problems I presented:


Problem #1:

You say the old 90 deg two phase was over 4 wires. If I instead put
it over three wires, with a shared neutral, would there still be two phases?
(my answer YES)


In fact they do and it comes over 5 wires. The windings look like
this + with ground at the center.
Why aren't you calling THAT 4 phase? The windings on both sides of the
center tap will act just like what we are talking about.



Put two 120V windings on the same shaft at the generator and feed it to the
house over three wires, shared neutral, with a 90 deg phase
difference between the two coils. Would there then be two phases entering
the homeowner;s house?

Yes or no?
(my answer YES)

Yes that would be 2 phase because of the phase difference between the
coils but to duplicate a house service, they would need to be IN phase
with each other so you would get 240v when you summed them together.

Go back to your batteries. When you connect them + to - in series, you
are attaching them IN phase. The current is always flowing in the same
direction and the voltage adds.
If you measured them from the center it might appear they are hooked
up opposite but you have to look at the system as a whole, not just
one segment.

If it's 180 phase difference, then what? Isn't that still two phases?
(YES)

If there is truly 180 difference in current flow, the output by
connecting them in series is zero.
You have to look at things as a system when you connect them together,
not just one small part.

On 7/28/18 3:25 PM, trader_4 wrote:

Separate system? Where did that requirement come from? Three phase
AFAIK is generated from 3 windings on the same shaft, separated by 120 deg.
Do diesel 3 phase generators have 3 motors? What's does a "separate system"
even mean? They can't be really separate and be locked at a fixed phase separation.

I guess this is as good a place as any to ask since you mentioned
diesel
generators. Most irrigation systems are powered by three phase 480. A
lot of those are generator powered. The power unit powers the well via
a power take off and also a belt driven generator on the front end.
The system motors driving the towers are three phase 480. The
control circuits are 120. So there's a transformer for the 120. It
takes two lines of the 480 and kicks it down to 120. There is also a
tap on that transformer secondary supplying 24 volts. What would you
call that?

On Tue, 31 Jul 2018 05:26:22 -0500, Dean Hoffman
wrote:

On 7/28/18 3:25 PM, trader_4 wrote:

Separate system? Where did that requirement come from? Three phase
AFAIK is generated from 3 windings on the same shaft, separated by 120 deg.
Do diesel 3 phase generators have 3 motors? What's does a "separate system"
even mean? They can't be really separate and be locked at a fixed phase separation.

I guess this is as good a place as any to ask since you mentioned
diesel
generators. Most irrigation systems are powered by three phase 480. A
lot of those are generator powered. The power unit powers the well via
a power take off and also a belt driven generator on the front end.
The system motors driving the towers are three phase 480. The
control circuits are 120. So there's a transformer for the 120. It
takes two lines of the 480 and kicks it down to 120. There is also a
tap on that transformer secondary supplying 24 volts. What would you
call that?


Omni Polly Faze.

On 07/30/2018 08:14 PM, trader_4 wrote:
Good grief. It's not an issue of software modeling. It's an issue of
what the circuit really is, how it really behaves. From a circuit
standpoint, you don't need to know if it came from a transformer or
if it came from a synthesized electronically generated source from
a battery. The 240/120 service looks like TWO ideal voltage sources,
that are 180 deg out of phase or equivalently, of opposite polarity
sharing a common neutral. There is no other way to model it. That's
all he's doing. That's what everybody does, because that's what it
is, what it behaves like. If you feel otherwise, show us your alternate
model.

It's a transformer. Single phase in yields single phase out.

All you got is a cheap parlor trick using a dual-trace scope.Â* Good grief!

this entire discussion is about semantics

for sine waves, a polarity inversion is equivalent to 180 deg phase shift.

The two operations are different, but the resulting signals are identical.

tastes great, less filling

choose one

mark