On 08/01/2018 01:42 PM, wrote:
On Wed, 1 Aug 2018 12:55:29 -0500, notX
wrote:

It would be possible to build a 3-phase motor that requires the phases
to be at 0, 90, and 100 degrees. I don't know of ANY benefit to doing
so, but it IS possible.

A 3 phase motor would still run on that, just not very efficiently.


I didn't say it would be efficient, just possible.

--
Mark Lloyd
http://notstupid.us/

"The unspiritual man does not receive the gifts of the Spirit of God,
for they are folly to him, and he is not able to understand them because
they are spiritually discerned." Paul, 1 Corinthians 2:14

On Thu, 2 Aug 2018 12:18:56 -0500, Mark Lloyd
wrote:

As to phases, I'd like to hear about the phase angles for that "3 phase"
from a double-tapped transformer secondary.

If you mean a center tapped "red leg" delta, 120 degrees, just like
any other 3p. They do center tap one of the transformers and ground it
there but the phase angles and current flow do not change.

On Thu, 2 Aug 2018 12:20:05 -0500, Mark Lloyd
wrote:

On 08/01/2018 01:42 PM, wrote:
On Wed, 1 Aug 2018 12:55:29 -0500, notX
wrote:

It would be possible to build a 3-phase motor that requires the phases
to be at 0, 90, and 100 degrees. I don't know of ANY benefit to doing
so, but it IS possible.

A 3 phase motor would still run on that, just not very efficiently.


I didn't say it would be efficient, just possible.
As long as there is any phase angle shift available, the motor will
start.
In a single phase motor they do it by creating an LC network in the
start winding. Any polyphase motor has that available natively.

On 08/02/2018 10:46 AM, wrote:


Again, that's why it's TWO voltage sources coming from the TWO halves
of the transformer and why it looks like, acts like and is two voltage
sources that are 180 out of phase or of alternate polarity, which is
the same thing.

so the problem here is the power engineer guy looks at the two signals that come off the pole into your house that are 180 deg apart and/or opposite polarity and in his mind these are ONE phase because he knows they were both derived from ONE phase of the 3 phase grid system and one is just inverted polarity of the other.

OK that is a valid view.


the signal engineer looks at the same two signals coming off the pole that are 180 deg apart and says, these are two sine waves that are 180 deg phase so it is TWO phases.

This is also a valid view.

Lets have a beer.


mark

This isn't the first time I've seen a disagreement where both sides are
right.

--
Mark Lloyd
http://notstupid.us/

"The unspiritual man does not receive the gifts of the Spirit of God,
for they are folly to him, and he is not able to understand them because
they are spiritually discerned." Paul, 1 Corinthians 2:14

On 8/2/2018 1:49 PM, Mark Lloyd wrote:

This isn't the first time I've seen a disagreement where both sides are right.

Not so fast, Mark!

The problem is when using trader_4's parlor trick definition, virtually every residential electrical service installed in the US is in violation of electrical code because the panels are only listed for single-phase service.

So don't blame me when some overzealous code nanny (they're out there) red tags your service...and good luck finding a two-phase panel replacement.

Oh, I almost forgot the most ridiculous argument of all.Â* Since your panel does not meet code, your insurance company can refuse to pay any claim caused by your improper electrical service equipment.Â* You might even have your children confiscated for
reckless endangerment of their lives.

On 8/1/2018 6:43 PM, wrote:

Your problem is you can't step back and look at this as a system. You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.


Trader's source says:
"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."
[I am not "rural" and my distribution is "single phase line to ground".]

Trader's source says that standard practice is that 240/120V systems are
single phase.

Trader's source suggests they should be 2 phases. There is no reason to
believe anyone but trader agrees.

None of the many people I have met that have worked on 3-phase systems
would call 240/120V systems 2 phases. Neither do manufacturers. Just
one reason is that it creates confusion with real 2-phase systems.
Another reason is it doesn't make sense.

All this has been argued in another long thread.

Trader can, of course, call it whatever he wants. That will alert people
familiar with power systems to what he knows.

And I don't remember anyone here who agrees with him, further
reinforcing his reputation as a crank.

bud
ee and licensed master electrician

On Thursday, August 2, 2018 at 5:49:48 PM UTC-4, bud-- wrote:
On 8/1/2018 6:43 PM, wrote:

Your problem is you can't step back and look at this as a system. You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.


Trader's source says:
"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."
[I am not "rural" and my distribution is "single phase line to ground".]

Trader's source says that standard practice is that 240/120V systems are
single phase.

Nice hack job Bud. What he said was:

"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. "



Trader's source suggests they should be 2 phases. There is no reason to
believe anyone but trader agrees.

He says they have been "treated" as single phase, but that what is actually
there are TWO PHASES. And then he proceeded to go through the complex
mathematical analysis of it as two phases to show how loading affects
the voltages at the transformer. This isn't some random source,
it's an electrical engineering professor, with 40 years experience,
presenting at a power industry conference of his peers. He's a life
fellow of the IEEE and his paper was published in that PEER REVIEWD
journal. If it's silly, wrong, then the IEEE would have had it withdrawn.





None of the many people I have met that have worked on 3-phase systems
would call 240/120V systems 2 phases.

I'm not arguing what it's commonly called. Like the engineerig prof,
I'm telling you what's really there from an electrical engineering perspective.
I acknowledged that they call it single phase, probably because it originates
from one phase of the 3 phases coming from the power generator. That
does not change what there, what you get, when you center tap a transformer..,
what you see on a scope. Your silly position is like saying that because
the stuff you blow your nose in is called Kleenex or tissues, it isn't
really a soft paper product made from trees.



Neither do manufacturers. Just
one reason is that it creates confusion with real 2-phase systems.
Another reason is it doesn't make sense.

It makes perfect sense. When you try to deny it, then you wind up like
Fretwell, unable to answer simple questions that a high school student
or beginning student in circuits 101 would ask. I'll provide those
questions at the end, let's see your answers.





All this has been argued in another long thread.

Irrelevant of course.



Trader can, of course, call it whatever he wants. That will alert people
familiar with power systems to what he knows.

Bud, why do you show up here and start attacking me? I'm comfortable
in my knowledge and have no need to attack. Unlike the folks on the
other side, I've answered ALL the questions put to me.





And I don't remember anyone here who agrees with him, further
reinforcing his reputation as a crank.

bud
ee and licensed master electrician

There's at least two posters here in this thread that agree. Plus
the electrical engineering professor. Where are you authorities that
explain why he's wrong?


OK, since you called my qualifications and knowledge into question,
class is in session.

Test question one:

Define N phase power?


Test question two:

According to Fretwell, two phase power existed 100 years ago, and it
was over two wires, 90 degrees phase difference. Suppose I run it
over 3 wires instead, with a shared neutral, make it 120V. So,
you have a generator supplying 120V, two coils, one shared neutral.
Would there still be two phases there? (I believe Fretwell said yes)
Your answer?

So now, I run that from the generator into a house, we have three wires,
120V, two phases.
If I change the phase difference to 179 degrees instead of 90
by rotating one coil, are there still two phases? Yes or no?

Now I rotate it to 180 phase difference. Are there still two phases,
yes or no?


And the final step above is absolutely IDENTICAL to what you have coming
into the house with 240/120. The electrons are behaving exactly the same.
If you disagree, explain how it's different.


Fretwell can't make it through the above, answer every question, because
it's clear he's cornered and the truth is obvious.

Problem number 3

I take 3 phase power with a neutral into a house. One phase is at zero,
one is at 120, one is at 240, correct?

Now I rotate one coil so that instead of 120, it's at 179. Are there
still three phases?

Now I rotate it one degree more, to 180. Are there still 3 phases,
yes or no?

Now take away the 240 phase. How many phases now? If it's not two,
explain why.

And if it is two, then again, it's ELECTRICALLY IDENTICAL TO 240/120 service.
IF you believe it's electrically different, explain why.


Problem number 4:

Draw the basic circuit model of 240/120 service. My model uses TWO
voltage sources, with a shared neutral. One is 120V sin(wt), the
other 120V sin(wt+180) or of alternate polarity connection, if you
like. That is the only way to model that circuit, because that is
what is there. When you center tap it, you now have TWO voltage
sources. Which by the way is exactly what the professor is saying,
you have two sources, 180 out of phase with each other. Tell us
your alternate model.


Note that none of the others here can make it through answering those
simple, very basic questions, because their arguments fall apart,
they are making it up as they go. Half way through, they cut it apart,
stop answering, and start talking about transformers. What's on that
service doesn't matter where it came from, whether it's a transformer or synthesized electronically from a battery. I defined N phase power and gave
a clear explanation that's consistent with what a first semester
electrical engineering student knows. I can and have answered all
those simple student questions consistent with electrical engineering.
Can you?

On Thursday, August 2, 2018 at 12:58:00 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:27:27 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:43:21 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:33:27 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 2:38:32 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:41:43 -0500, Sam E
wrote:

On 07/31/2018 03:24 PM, wrote:

[snip]

If I take your concept that every segment of a winding constitutes a
phase, why not just tap that secondary twice, create 3 segments, then
I have 3 phases and I can run a 3p motor.

Somehow, a wiring diagram for that might help.

And 2 phases, 90 degrees apart DOES exist. It's just inside a
capacitor-start motor.

I can draw it quite easily and if it is from a 3 phase source it is a
delta but if it is from a single phase source it is a toaster.

The thing you can't grasp is 180 degrees out is just a different view
of a single phase secondary.
I really don't care anymore.

What you can't grasp is that how two different phases are derived,
doesn't matter. The only issue is how many phases you see when
you analyze it. And 240/120 is nothing more than two 120V voltage
sources sharing a common neutral, one 180 out of phase from the other.

I've asked a dozen times, if instead of from a transformer the you
had two 120V coils coming from a generator, two wires, sharing a
common return and those coils were 120 out of phase on the shaft,
would there be two phases going into the house? At 179 deg separation
would there be two? How about moving one coil one more degree,
what happens then? If the additional phase disappears, then I'd
say that's a parlor trick. And if it doesn't then what you have
going into the house from that experiment is exactly the same
electrically as what is derived from the center tapped transformer.
You can't tell the difference, they perform exactly the same,
they are the same.

Your problem is you can't step back and look at this as a system.


I can analyze it any way you like. It does not change the way the
electrons are flowing in the 3 wires coming into the house and that
they represent TWO voltage sources, one 180 deg out of phase with
the other, or of opposite polarity if you like. Out of phase 180 and
opposite polarity are the same thing in an AC system.


No you are simply wrong. At any particular instant the current is
flowing in exactly the same direction in the system.

There are 3 conductors, so how can it possibly be all flowing in
the same direction? It would pile up in the house.



You have to look
at the source. ALL of the power is coming in from the grid in the same
direction at any given instant and Mr Kirchoff says the current in
will always equal the current out.

He actually said that the sum of the currents at a node is zero.
Which does translate into the fact that all the current entering the
house has to leave the house. Which of course is yet another red herring,
IDK what your point is here. That is true if there is one phase, two
phases, N phases.





You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.

The neutral is the center of the universe, not by chance, but by design.
Yet somehow you and that other guy here claim it's a parlor trick to hook
up a scope and use the common point of the system as the ground,
reference point, etc. And when you do that, what do you see? Two
conductors, differing in phase by 180 degrees. Which of course is
exactly what the electrical engineering professor with 40 years
experience, consulting for utilities, presenting his paper at the power
industry conference said too.

You are all still trying to rationalize what you see standing in one
particular spot and not looking at the whole system.

Ridiculous. It's not a random spot, it's the SYSTEM ground, it's reference
point. I can and have defined N phase power and it's completely defined
by the number of voltage sources, their amperage and phase relationship
to each other. It matters not a wit if it's generated by a transformer,
by a generator, or again, synthesized electronically from a DC battery.
If I synthesized 3 phase from a battery, is it DC?


Simply the fact
that you think current suddenly switches direction in the same part of
the cycle demonstrates that.

IDK where you got that from.


If we assume current flows negative to
positive (no I am not going to start up that fight)
If L1 is negative at some particular time, current will flow from L1
towards the grounded conductor but at that same time L2 is positive
and current will keep going in that same direction moving away from
the grounded conductor ending up in L2. In fact the grounded conductor
really has nothing to do with it when you get back to the transformer.
the current is always flowing in the same direction. That is why the
utility DOES NOT METER the neutral.


Current doesn't have to be flowing in L2 at all, if all you have is
a 120V load on L1, the current in L2 is ZERO. And all of the above has
nothing to do with the fact that those two transformer coils are
separate 120V voltage sources that are 180 deg out of phase or connected
in alternate polarity, which is exactly the same thing. You could have
100 amps flowing in one half, zero amps flowing in the other.

Go see my reply to Bud and take the simple quiz at the end. See if you
can make it through one step at a time, answer every question. Youy
can't because you're quickly caught up in contradictions. When you
apply electrical engineering uniformly, there are no contradictions.

On Thursday, August 2, 2018 at 1:08:42 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:33:38 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:46:09 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:52:58 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 2:41:24 PM UTC-4, wrote:
On Wed, 1 Aug 2018 10:49:18 -0700 (PDT), trader_4
wrote:



Explain that to Trader. He seems to think that every time you tap a
secondary you create another phase.

You're completely and deliberately misrepresenting what I've posted here.
You said:

"If the tap was 2/3ds the way along the secondary, would
you say they were now 239 degrees out of phase?"

IDK where that came from, but I replied that if you made that tap,
you'd have one coil with 240 * .66 VOLTS, the other with 240 * .33 VOLTS.
The phases of the two would be exactly the same as with the center tap.
You'd see two phases from the ends of the transformer with respect to
the midpoint.

Exactly except you are simply looking at one phase, looking in 2
directions from an arbitrary point along the winding.

Which creates TWO 120V voltage sources that are 180 deg out of phase
with each other with respect to the neutral.



Do you think the hands on your clock change direction at 12 and 6?
After all, first they are going down, then they are going up.

Do you not understand that 180 deg phase shift is the same as
opposite polarity? If there aren't two phases coming into the house,
why can't I parallel any two receptacles at random? It's just like
with 3 phases. If I want to parallel two, I better be sure they are
the same phase conductor.

Someone comes to you and asks, why can't I just parallel any two
receptacles in the house? What's your answer? And the answer shouldn't
involve transformers, because the answer should apply regardless
of how the service is provided. My answer, there are two different
phases, 180 deg apart, works regardless of how the two phases
got there. Could come directly from a generator as I've cited for
example many times now. Could come purely electronically synthesized
off a battery, could come from an unknown black box, could come from
a center tapped transformer. It doesn't matter, it;s all covered,
all explained, it all looks, acts and behaves exactly the same.
And it doesn't have to be 180, could be 179 deg, 90 deg, etc.
It's all covered. It's the voltages, currents and phase relationships
that define it, not how it was created.

Quite simply you can't connect the ungrounded conductors together
because they are at opposite ends of a 240v single phase secondary.

Could you connect them together if they came out of a black box,
where you didn't know how they were generated? Could you connect
them together if the originated from a generator, with two coils
separated by 180 deg? That's the beauty of consistent definitions.
We define and analyze without having to know exactly how it's
generated, because it doesn't matter.


It certainly matters where they are generated because if they came
from totally separate sources you could connect them together, no
matter how they were polarized and the voltages would either buck or
boost. but there would be no fire. It is the fact that you are using
two halves of a single winding that makes current flow from L1 to L2.

Ridiculous. The behavior of that 240/120 3 wire power service is
defined by the voltages and phase relationships. Same with any power
source. Where it comes form matters not a wit. You have TWO 120V voltage
sources sharing a common neutral, 180 deg out of phase with each other,
or connected in reverse polarity if you like. THAT is what's there.
It;s all you need to know. It could come from a nuclear power plant,
a transformer, or be synthesized electronically. IT doesn't even have
to exist at all, we can analyze it using ideal voltage sources. If
you disagree, give us your circuit model, the professor and I gave
you ours, from elec engineering circuits 101.





Person asks, can I parallel these wires of a three phase system?
My answer: Yes, if they are of the same phase, otherwise no.

Person asks, can I parallel these two receptacles in my house?
My answer: Yes, if they are of the same phase, otherwise no.

In a 3 phase system they are different independent phases so you can
connect them all together (delta)

See, there you go again. Instead of sticking to the example, it's off
to the wilderness. I can explain to a student why you can't parallel
any two outlets, they are 180 deg out of phase. If they were 120V and
in phase, you could parallel them.





The grounded conductor does nor even enter into it at all and there
are not 2 phases at all.


What? The neutral is suddenly gone now? You can't get 120V without
the neutral, except for the special, unusual case where there are loads
on both sides and they are exactly balanced.

Getting 120 has nothing to do with how many phases you have.

In general, that's true.


It is
still the same phase, just cut in half.

It's not just one voltage source when you cut it in half, it's TWO.
And they are tied together 180 deg out of phase, or with opposite
polarity if you like.


If I cut a cookie in half do I have 2 halves of the same cookie or do
I suddenly have two cookies?

Do cookies have polarity and phase?




Again, that's why it's TWO voltage sources coming from the TWO halves
of the transformer and why it looks like, acts like and is two voltage
sources that are 180 out of phase or of alternate polarity, which is
the same thing.

That is where you are just wrong. It is not 2 sources, it is two ends
of one voltage source. Do you understand what a "circuit" means?
It is starting to make sense now, why these professors have to come up
with such convoluted "models" to explain such a simple concept.

I've asked you about 6 times now to give you your basic circuit model
that uses just one source to get 240/120. I've given you mine, the same
as the professor, the same as any first semester EE would. It's TWO
120V voltage sources tied together, sharing the neutral, one 180 deg
out of phase with the other or connected with opposite polarity.

If it;s so simple, where is your model? Where, BTW is your definition
of N phase? How can you be arguing about what something is, when you
can't even define it? And note the definition doesn't rely on transformers,
generators, batteries or anything else.

On Thursday, August 2, 2018 at 1:14:17 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:42:04 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:51:03 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:59:37 -0700 (PDT), trader_4
wrote:

If they are the same phase, same voltage, then there is no voltage

Now you are confusing "phase" with difference in potential.

Not confusing anything at all. If two conductors are of the same phase
and same voltage, then there is no potential difference between them.



There is
always a difference of potential in any circuit or current will not
flow. Mr Ohm teaches us that. That is even true with DC with no phase
at all.

There isn't a difference in potential and no current flows if I connect
two conductors that are the same phase and voltage. That's why I can
parallel receptacles in a house that are on the same phase and nothing
happens. If I try to parallel ones that are on the two different 120V
phases, then Kapow!

You are over complicating a simple fact. You are connecting line 1 to
line 2, the two ends of the secondary. Where the ground happens to be
or even the fact that there is a center tap does not enter into it at
all at that point.

That's true, but the center tap changes it dramatically, which is the
whole purpose of doing it, BTW. Now instead of it being ONE 240V voltage
source you have TWO 120V voltage sources with different currents flowing
in each half. One could have 100 amps, the other zero amps.





Ungrounded conductors do not necessarily mean phase.

I never said otherwise.

OK then, there are 2 ungrounded conductors coming into your house, not
2 phases.

There are two ungrounded conductors that are 180 deg out of phase with
each other with respect to the NEUTRAL. It's not some obscure, bizarre
reference point, it's the system ground, it's one and only most basic
reference point.




Do you agree a single untapped secondary grounded at one end like
Europe would be single phase? (2xx volts and ground no center tap)

Yes, because then it's ONE voltage source. When you center tap it
you create TWO separate voltage sources tied together

No there is still ONE source, that happens to be divided., It is still
just one secondary to one transformer.

It becomes TWO voltage sources when you center tap it. Feel free to give
us your circuit model that doesn't use two 120V sources. The prof and I
gave you ours, it's from elec eng circuits 101, first couple of days.

On Thursday, August 2, 2018 at 1:17:28 PM UTC-4, wrote:
On Thu, 2 Aug 2018 09:33:11 -0700 (PDT), trader_4
wrote:

On Thursday, August 2, 2018 at 11:46:38 AM UTC-4, wrote:

Again, that's why it's TWO voltage sources coming from the TWO halves
of the transformer and why it looks like, acts like and is two voltage
sources that are 180 out of phase or of alternate polarity, which is
the same thing.

so the problem here is the power engineer guy looks at the two signals that come off the pole into your house that are 180 deg apart and/or opposite polarity and in his mind these are ONE phase because he knows they were both derived from ONE phase of the 3 phase grid system and one is just inverted polarity of the other.

OK that is a valid view.


the signal engineer looks at the same two signals coming off the pole that are 180 deg apart and says, these are two sine waves that are 180 deg phase so it is TWO phases.

This is also a valid view.

Lets have a beer.


mark

I'm good with that. It's consistent with what I said in my first post.

The problem is you are bring audio thinking into a power scenario.

You know, I kind of saw that coming. Mako said "signal" and I let it go.
I didn't want to be overly critical or accused of nitpicking and I thought
he has it about right. But it isn't an issue of from a signal prospective.
It's basic electrical engineering circuit analysis 101.

You seem to think that there is one way of doing circuit analysis
for power circuits and another for audio circuits. It's all one and the
same thing. I gave you my circuit model using two 120V voltage sources
that are either 180 deg out of phase with each other or connected with
opposite polarity, same thing. That is your 240/120 service and it could
come from a transformer, be synthesized from a battery, or just exist on
a piece of paper. It doesn't matter, it defines what's there and it's
all you need to know.





I would even contend that the audio guy would just call this a push
pull amp on one phase. The other stereo channel would be the other
phase. (hence "phasing" speakers)

The audio guy would hook up his scope ground to the ground on his audio
system and take a look at the phase relationships. When you do that in
your house, connect the scope ground to the house neutral/ground,
what do you see? TWO 120V voltage sources that are 180 deg out of phase
with each other. That explains why you can't randomly parallel any
two receptacles. It explains how you get 240V from one hot to the other.
I don't need to go outside, look for a transformer, talk about ends of
transformers. It doesn't matter if that service came from a synthesized
source powered by a car battery. What's there is what defines what you
have. Knowing what I just stated, and how many amps I am allowed, is
all I need to know to design with it, to use it.

On Thu, 2 Aug 2018 16:58:33 -0700 (PDT), trader_4
wrote:

On Thursday, August 2, 2018 at 12:58:00 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:27:27 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:43:21 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:33:27 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 2:38:32 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:41:43 -0500, Sam E
wrote:

On 07/31/2018 03:24 PM, wrote:

[snip]

If I take your concept that every segment of a winding constitutes a
phase, why not just tap that secondary twice, create 3 segments, then
I have 3 phases and I can run a 3p motor.

Somehow, a wiring diagram for that might help.

And 2 phases, 90 degrees apart DOES exist. It's just inside a
capacitor-start motor.

I can draw it quite easily and if it is from a 3 phase source it is a
delta but if it is from a single phase source it is a toaster.

The thing you can't grasp is 180 degrees out is just a different view
of a single phase secondary.
I really don't care anymore.

What you can't grasp is that how two different phases are derived,
doesn't matter. The only issue is how many phases you see when
you analyze it. And 240/120 is nothing more than two 120V voltage
sources sharing a common neutral, one 180 out of phase from the other.

I've asked a dozen times, if instead of from a transformer the you
had two 120V coils coming from a generator, two wires, sharing a
common return and those coils were 120 out of phase on the shaft,
would there be two phases going into the house? At 179 deg separation
would there be two? How about moving one coil one more degree,
what happens then? If the additional phase disappears, then I'd
say that's a parlor trick. And if it doesn't then what you have
going into the house from that experiment is exactly the same
electrically as what is derived from the center tapped transformer.
You can't tell the difference, they perform exactly the same,
they are the same.

Your problem is you can't step back and look at this as a system.


I can analyze it any way you like. It does not change the way the
electrons are flowing in the 3 wires coming into the house and that
they represent TWO voltage sources, one 180 deg out of phase with
the other, or of opposite polarity if you like. Out of phase 180 and
opposite polarity are the same thing in an AC system.


No you are simply wrong. At any particular instant the current is
flowing in exactly the same direction in the system.

There are 3 conductors, so how can it possibly be all flowing in
the same direction? It would pile up in the house.


Don't you think the circuit goes all the way back to the transformer?
At any given moment all of the current is flowing the same way in the
transformer secondary and exactly the same amount of current is
flowing in the house. Say it starts in L1 of the transformer, it is
flowing towards L2. Any unbalanced current will be flowing in the
neutral but it is still flowing towards L2. If the unbalance favors
the L1 side it goes out on the neutral but it is still flowing the
same way in the transformer.


You have to look
at the source. ALL of the power is coming in from the grid in the same
direction at any given instant and Mr Kirchoff says the current in
will always equal the current out.

He actually said that the sum of the currents at a node is zero.
Which does translate into the fact that all the current entering the
house has to leave the house. Which of course is yet another red herring,
IDK what your point is here. That is true if there is one phase, two
phases, N phases.

If the balance on both ungrounded conductors is equal, there is zero
current in the neutral.


You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.

The neutral is the center of the universe, not by chance, but by design.
Yet somehow you and that other guy here claim it's a parlor trick to hook
up a scope and use the common point of the system as the ground,
reference point, etc. And when you do that, what do you see? Two
conductors, differing in phase by 180 degrees. Which of course is
exactly what the electrical engineering professor with 40 years
experience, consulting for utilities, presenting his paper at the power
industry conference said too.

You are all still trying to rationalize what you see standing in one
particular spot and not looking at the whole system.

Ridiculous. It's not a random spot, it's the SYSTEM ground, it's reference
point. I can and have defined N phase power and it's completely defined
by the number of voltage sources, their amperage and phase relationship
to each other. It matters not a wit if it's generated by a transformer,
by a generator, or again, synthesized electronically from a DC battery.
If I synthesized 3 phase from a battery, is it DC?


It is certainly a random spot, you can ground the system in at least 3
places.


Simply the fact
that you think current suddenly switches direction in the same part of
the cycle demonstrates that.

IDK where you got that from.


If we assume current flows negative to
positive (no I am not going to start up that fight)
If L1 is negative at some particular time, current will flow from L1
towards the grounded conductor but at that same time L2 is positive
and current will keep going in that same direction moving away from
the grounded conductor ending up in L2. In fact the grounded conductor
really has nothing to do with it when you get back to the transformer.
the current is always flowing in the same direction. That is why the
utility DOES NOT METER the neutral.


Current doesn't have to be flowing in L2 at all, if all you have is
a 120V load on L1, the current in L2 is ZERO. And all of the above has
nothing to do with the fact that those two transformer coils are
separate 120V voltage sources that are 180 deg out of phase or connected
in alternate polarity, which is exactly the same thing. You could have
100 amps flowing in one half, zero amps flowing in the other.

When it gets back to the transformer it is still flowing towards L2


Go see my reply to Bud and take the simple quiz at the end. See if you
can make it through one step at a time, answer every question. Youy
can't because you're quickly caught up in contradictions. When you
apply electrical engineering uniformly, there are no contradictions.

On Thu, 2 Aug 2018 16:45:32 -0700 (PDT), trader_4
wrote:

Test question one:

Define N phase power?

A system with "n" number of separate phases coming at different
angular displacements and coming from separate windings in a
Separately Derived Source or a Utility.
That does not include simply tapping a single phase transformer tho
because there is only one phase at the source.


Test question two:

According to Fretwell, two phase power existed 100 years ago, and it
was over two wires, 90 degrees phase difference. Suppose I run it
over 3 wires instead, with a shared neutral, make it 120V. So,
you have a generator supplying 120V, two coils, one shared neutral.
Would there still be two phases there? (I believe Fretwell said yes)
Your answer?

Since you are not properly describing how 2 phase works, the question
is bogus.
There are 2 separate windings with primaries at different phase
relationships (90 degrees). You can derive 2p from a 2p generator (the
way it was done originally) and also from a 3 phase source in some
retrofit installations.
You can't get there from single phase ... period.

Fretwell can't make it through the above, answer every question, because
it's clear he's cornered and the truth is obvious.

I can't get through a question when the initial supposition is
bull****. Find out a little more about 2 phase and get back to me,.


Problem number 3

I take 3 phase power with a neutral into a house. One phase is at zero,
one is at 120, one is at 240, correct?

Now I rotate one coil so that instead of 120, it's at 179. Are there
still three phases?

Now I rotate it one degree more, to 180. Are there still 3 phases,
yes or no?

Now take away the 240 phase. How many phases now? If it's not two,
explain why.

To start with, there is no way to get to 179 but as soon as you get to
180, and both windings are in phase (current flowing in the same
direction in both secondaries at the same time), you have a single
phase that doubles the voltage. If they are out of phase, voltage is
zero. They buck each other. You can see that in a GFCI.


And if it is two, then again, it's ELECTRICALLY IDENTICAL TO 240/120 service.
IF you believe it's electrically different, explain why.

Yes it is exactly the same as your house, single phase.


Problem number 4:

Draw the basic circuit model of 240/120 service. My model uses TWO
voltage sources, with a shared neutral. One is 120V sin(wt), the
other 120V sin(wt+180) or of alternate polarity connection, if you
like. That is the only way to model that circuit, because that is
what is there. When you center tap it, you now have TWO voltage
sources. Which by the way is exactly what the professor is saying,
you have two sources, 180 out of phase with each other. Tell us
your alternate model.


Note that none of the others here can make it through answering those
simple, very basic questions, because their arguments fall apart,
they are making it up as they go. Half way through, they cut it apart,
stop answering, and start talking about transformers. What's on that
service doesn't matter where it came from, whether it's a transformer or synthesized electronically from a battery. I defined N phase power and gave
a clear explanation that's consistent with what a first semester
electrical engineering student knows. I can and have answered all
those simple student questions consistent with electrical engineering.
Can you?




I am not sure how you get to two sources when there is only one
secondary winding, no matter where you tap it.

On Tue, 24 Jul 2018 08:57:29 -0700 (PDT), trader_4
wrote:

On Tuesday, July 24, 2018 at 11:28:39 AM UTC-4, Bubba wrote:
On 7/24/2018 9:53 AM, trader_4 wrote:
Take two generators built on a single shaft (the same way that three-phase generators are built on a single shaft) so that you get two 120VAC outputs that are 180 degrees out of phase. Would it be reasonable to call this two-phase power?

Bubba, what's your answer?

The transformer for my house has a single phase input.Â* The output of the transformer is single phase as well.Â* I don't have a two-phase generator on my utility pole.

There you have it, typical. Instead of responding to the simple questions
that go to the heart of the matter, just diversion. Others can note that
I responded to your oscilloscope connection question. Note that I also
gave you an opportunity to define for us what makes a system one phase,
two phase, N phase and then explain why residential doesn't meet the
definition of two phase. If you can't define it, then it becomes
arbitrary. Which is kind of what I and the moderator at the forum said,
it's just semantics.


OK lets try this one more time. At my utility I decided to ground one
end of the secondary (L1) instead of the center tap. (like most of the
civilized world according to Bod) I still center tap the transformer
and have 3 buses in my service panel. (lets ignore how you would need
to do overcurrent for now but the answer is a split bus panel).

Everything works exactly the same except I have the neutral
(centertap) bus at 120 above ground and L2 is 240v above ground.
Nothing in your house will notice the difference if you are not using
the EGC (ground) for a current carrying conductor (a violation of
250.6)

Do you still think I have 2 phases?

http://gfretwell.com/electrical/End%...nter%20tap.jpg

On Thursday, August 2, 2018 at 10:28:18 PM UTC-4, wrote:
On Thu, 2 Aug 2018 16:58:33 -0700 (PDT), trader_4
wrote:

On Thursday, August 2, 2018 at 12:58:00 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:27:27 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:43:21 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:33:27 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 2:38:32 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:41:43 -0500, Sam E
wrote:

On 07/31/2018 03:24 PM, wrote:

[snip]

If I take your concept that every segment of a winding constitutes a
phase, why not just tap that secondary twice, create 3 segments, then
I have 3 phases and I can run a 3p motor.

Somehow, a wiring diagram for that might help.

And 2 phases, 90 degrees apart DOES exist. It's just inside a
capacitor-start motor.

I can draw it quite easily and if it is from a 3 phase source it is a
delta but if it is from a single phase source it is a toaster.

The thing you can't grasp is 180 degrees out is just a different view
of a single phase secondary.
I really don't care anymore.

What you can't grasp is that how two different phases are derived,
doesn't matter. The only issue is how many phases you see when
you analyze it. And 240/120 is nothing more than two 120V voltage
sources sharing a common neutral, one 180 out of phase from the other.

I've asked a dozen times, if instead of from a transformer the you
had two 120V coils coming from a generator, two wires, sharing a
common return and those coils were 120 out of phase on the shaft,
would there be two phases going into the house? At 179 deg separation
would there be two? How about moving one coil one more degree,
what happens then? If the additional phase disappears, then I'd
say that's a parlor trick. And if it doesn't then what you have
going into the house from that experiment is exactly the same
electrically as what is derived from the center tapped transformer.
You can't tell the difference, they perform exactly the same,
they are the same.

Your problem is you can't step back and look at this as a system.


I can analyze it any way you like. It does not change the way the
electrons are flowing in the 3 wires coming into the house and that
they represent TWO voltage sources, one 180 deg out of phase with
the other, or of opposite polarity if you like. Out of phase 180 and
opposite polarity are the same thing in an AC system.


No you are simply wrong. At any particular instant the current is
flowing in exactly the same direction in the system.

There are 3 conductors, so how can it possibly be all flowing in
the same direction? It would pile up in the house.


Don't you think the circuit goes all the way back to the transformer?

Of course it does, where the transformer acts as two 120v voltage
sources. But I don't need a transformer to define N phase power.
Still waiting for your definition of that. How can you be here arguing
about what something is, but can't define it? My engineering world
everything is defined and consistently applied. I could replace that
transformer with any two voltage sources that are 120V sine waves,
that share a common neutral, that are 180 out of phase and the power
going to the house would be exactly the same.




At any given moment all of the current is flowing the same way in the
transformer secondary and exactly the same amount of current is
flowing in the house. Say it starts in L1 of the transformer, it is
flowing towards L2. Any unbalanced current will be flowing in the
neutral but it is still flowing towards L2.

The unbalanced part never goes into the second half of the coil.


If the unbalance favors
the L1 side it goes out on the neutral but it is still flowing the
same way in the transformer.

I agree with that. And it's flowing through two voltage sources,
(the two halves of the secondary) that with the center tap, are
of opposite polarity, which is the same thing as 180 deg out of phase.






You have to look
at the source. ALL of the power is coming in from the grid in the same
direction at any given instant and Mr Kirchoff says the current in
will always equal the current out.

He actually said that the sum of the currents at a node is zero.
Which does translate into the fact that all the current entering the
house has to leave the house. Which of course is yet another red herring,
IDK what your point is here. That is true if there is one phase, two
phases, N phases.

If the balance on both ungrounded conductors is equal, there is zero
current in the neutral.

Sure, that's the special case, not the general case.





You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.

The neutral is the center of the universe, not by chance, but by design.
Yet somehow you and that other guy here claim it's a parlor trick to hook
up a scope and use the common point of the system as the ground,
reference point, etc. And when you do that, what do you see? Two
conductors, differing in phase by 180 degrees. Which of course is
exactly what the electrical engineering professor with 40 years
experience, consulting for utilities, presenting his paper at the power
industry conference said too.

You are all still trying to rationalize what you see standing in one
particular spot and not looking at the whole system.

Ridiculous. It's not a random spot, it's the SYSTEM ground, it's reference
point. I can and have defined N phase power and it's completely defined
by the number of voltage sources, their amperage and phase relationship
to each other. It matters not a wit if it's generated by a transformer,
by a generator, or again, synthesized electronically from a DC battery.
If I synthesized 3 phase from a battery, is it DC?


It is certainly a random spot, you can ground the system in at least 3
places.

That's beyond absurd. The ground is the REFERENCE POINT for your SYSTEM.
It was deliberately chosen by the folks who set up this power SYSTEM,
not by me. So, it's the logical place to connect the ground reference
of your oscilloscope to analyze what's there. It's not a parlor trick,
some trick spot, that I selected.






Simply the fact
that you think current suddenly switches direction in the same part of
the cycle demonstrates that.

IDK where you got that from.


If we assume current flows negative to
positive (no I am not going to start up that fight)
If L1 is negative at some particular time, current will flow from L1
towards the grounded conductor but at that same time L2 is positive
and current will keep going in that same direction moving away from
the grounded conductor ending up in L2. In fact the grounded conductor
really has nothing to do with it when you get back to the transformer.
the current is always flowing in the same direction. That is why the
utility DOES NOT METER the neutral.


Current doesn't have to be flowing in L2 at all, if all you have is
a 120V load on L1, the current in L2 is ZERO. And all of the above has
nothing to do with the fact that those two transformer coils are
separate 120V voltage sources that are 180 deg out of phase or connected
in alternate polarity, which is exactly the same thing. You could have
100 amps flowing in one half, zero amps flowing in the other.

When it gets back to the transformer it is still flowing towards L2

No, it's not. If I just have a 120V load on the L1 side, I could cut
out and remove the other half of the transformer secondary, the L2 side.
There is no current flow in it. Current is flowing in one half of the
secondary only.





Go see my reply to Bud and take the simple quiz at the end. See if you
can make it through one step at a time, answer every question. Youy
can't because you're quickly caught up in contradictions. When you
apply electrical engineering uniformly, there are no contradictions.



You haven't taken your simple circuits 101 quiz yet:

Test question one:

Define N phase power?


Test question two:

According to Fretwell, two phase power existed 100 years ago, and it
was over two wires, 90 degrees phase difference. Suppose I run it
over 3 wires instead, with a shared neutral, make it 120V. So,
you have a generator supplying 120V, two coils, one shared neutral.
Would there still be two phases there? (I believe Fretwell said yes)
Your answer?

So now, I run that from the generator into a house, we have three wires,
120V, two phases.
If I change the phase difference to 179 degrees instead of 90
by rotating one coil, are there still two phases? Yes or no?

Now I rotate it to 180 phase difference. Are there still two phases,
yes or no? If you disagree, explain how it's different.


(My answer is yes and the final step above makes it absolutely IDENTICAL
to what you have coming into the house with 240/120. The electrons
are behaving exactly the same. )


Problem number 3

I take 3 phase power with a neutral into a house. One phase is at zero,
one is at 120, one is at 240, correct? I can see them on a scope, yes?

Now I rotate one coil so that instead of 120, it's at 179. Are there
still three phases?

Now I rotate it one degree more, to 180. Are there still 3 phases,
yes or no?

Now take away the 240 phase. How many phases now? If it's not two,
explain why.

And if it is two, then again, it's ELECTRICALLY IDENTICAL TO 240/120 service.
IF you believe it's electrically different, explain why and how it matters
in terms of the behavior of the electrons in the service conductors.


Problem number 4:

Draw the basic circuit model of 240/120 service. My model uses TWO
voltage sources, with a shared neutral. One is 120V sin(wt), the
other 120V sin(wt+180) or of alternate polarity connection, if you
like. That is the only way to model that circuit, because that is
what is there. When you center tap it, you now have TWO voltage
sources. Which by the way is exactly what the professor is saying,
you have two sources, 180 out of phase with each other, that's how
you treat it. Do you agree with that? If not, tell us your alternate model.

Problem number 4:

Someone asks why they can't randomly parallel any two receptacles in a house.
My answer is, because you have two 120V voltage sources that are 180 deg
out of phase with each other or of alternate polarity if you like.
If they were of the same phase or polarity, you could parallel them.
Your answer?


I can and have answered all those simple student questions consistent
with electrical engineering, one after the other, without wandering off
into the wilderness. Can you?

On Friday, August 3, 2018 at 12:02:12 AM UTC-4, wrote:
On Tue, 24 Jul 2018 08:57:29 -0700 (PDT), trader_4
wrote:

On Tuesday, July 24, 2018 at 11:28:39 AM UTC-4, Bubba wrote:
On 7/24/2018 9:53 AM, trader_4 wrote:
Take two generators built on a single shaft (the same way that three-phase generators are built on a single shaft) so that you get two 120VAC outputs that are 180 degrees out of phase. Would it be reasonable to call this two-phase power?

Bubba, what's your answer?

The transformer for my house has a single phase input.Â* The output of the transformer is single phase as well.Â* I don't have a two-phase generator on my utility pole.

There you have it, typical. Instead of responding to the simple questions
that go to the heart of the matter, just diversion. Others can note that
I responded to your oscilloscope connection question. Note that I also
gave you an opportunity to define for us what makes a system one phase,
two phase, N phase and then explain why residential doesn't meet the
definition of two phase. If you can't define it, then it becomes
arbitrary. Which is kind of what I and the moderator at the forum said,
it's just semantics.


OK lets try this one more time. At my utility I decided to ground one
end of the secondary (L1) instead of the center tap. (like most of the
civilized world according to Bod) I still center tap the transformer
and have 3 buses in my service panel. (lets ignore how you would need
to do overcurrent for now but the answer is a split bus panel).

Everything works exactly the same except I have the neutral
(centertap) bus at 120 above ground and L2 is 240v above ground.
Nothing in your house will notice the difference if you are not using
the EGC (ground) for a current carrying conductor (a violation of
250.6)

Do you still think I have 2 phases?

http://gfretwell.com/electrical/End%...nter%20tap.jpg


Yes, because your neutral is still connected to the center tap.
So, inside the house you will still see two hots at 120V with respect to
the neutral, one 180 deg out of phase with the other, or of alternate
polarity if you like. Hook up a scope, connecting the scope ground
reference to the neutral. The SYSTEM neutral, not some parlor trick
point that I've been accused of using. What do you see? Two hots,
120v, 180 out of phase. I can do the same with 3 phase, run it into
the house. I'd see one sine wave at 0 deg, one at 120 deg, one at 240 deg,
correct? Rotate the 120 deg coil to 180, what do you see now? It's
a sine wave at 180, correct? Are there still 3 phases there or did
one just disappear? Now remove the 240 phase conductor. Three minus
one is TWO. And what you have left is exactly identical to 240/120
service. Two hots, 180 deg out of phase with each other.

On Friday, August 3, 2018 at 12:40:21 PM UTC-4, bud-- wrote:
On 8/2/2018 5:45 PM, trader_4 wrote:
On Thursday, August 2, 2018 at 5:49:48 PM UTC-4, bud-- wrote:
On 8/1/2018 6:43 PM, wrote:

Your problem is you can't step back and look at this as a system. You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.


Trader's source says:
"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."
[I am not "rural" and my distribution is "single phase line to ground".]

Trader's source says that standard practice is that 240/120V systems are
single phase.

Nice hack job Bud. What he said was:

I quoted _exactly_ what he said.
Distribution engineers consider 240/120 to be single phase.


Trader's source suggests they should be 2 phases. There is no reason to
believe anyone but trader agrees.

He says they have been "treated" as single phase, but that what is actually
there are TWO PHASES.

In his opinion.


None of the many people I have met that have worked on 3-phase systems
would call 240/120V systems 2 phases.

I'm not arguing what it's commonly called. Like the engineerig prof,
I'm telling you what's really there from an electrical engineering perspective.

In your opinion.

It's not a matter of opinion. It's a fact to anyone that's passed
circuits 101. That's why I can apply circuits 101 and answer all those
questions and you and Fretwell can't.





Manufacturers and people who actually work with multiphase don't agree.

But you can call it whatever you want to if you don't mind problems
communicating with people in the power industry.

So, the guy who came in attacking, claiming to be an expert,
can't answer the simple electrical
engineering circuits 101 questions I posed. I can and did. Nuff said.
And if you bothered to read my first post on the issue, I clearly said
that while there are two phases there, it's not how it's referred to
in the industry. Following that logic, you can only talk about the
stuff you blow your nose in as Kleenex or tissues, that to analyze
it, describe what it really is, as a soft paper product made from
trees, isn't allowed. The IEEE Fellow knows what's there. I know
what;s there. And we can answer these simple questions that a beginning
student could ask a teacher. You can't. Thanks for playing.


Test question one:

Define N phase power?


Test question two:

According to Fretwell, two phase power existed 100 years ago, and it
was over two wires, 90 degrees phase difference. Suppose I run it
over 3 wires instead, with a shared neutral, make it 120V. So,
you have a generator supplying 120V, two coils, one shared neutral.
Would there still be two phases there? (I believe Fretwell said yes)
Your answer?

So now, I run that from the generator into a house, we have three wires,
120V, two phases.
If I change the phase difference to 179 degrees instead of 90
by rotating one coil, are there still two phases? Yes or no?

Now I rotate it to 180 phase difference. Are there still two phases,
yes or no? If you disagree, explain how it's different.


(My answer is yes and the final step above makes it absolutely IDENTICAL
to what you have coming into the house with 240/120. The electrons
are behaving exactly the same. )


Problem number 3

I take 3 phase power with a neutral into a house. One phase is at zero,
one is at 120, one is at 240, correct? I can see them on a scope, yes?

Now I rotate one coil so that instead of 120, it's at 179. Are there
still three phases?

Now I rotate it one degree more, to 180. Are there still 3 phases,
yes or no?

Now take away the 240 phase. How many phases now? If it's not two,
explain why.

And if it is two, then again, it's ELECTRICALLY IDENTICAL TO 240/120 service.
IF you believe it's electrically different, explain why and how it matters
in terms of the behavior of the electrons in the service conductors.


Problem number 4:

Draw the basic circuit model of 240/120 service. My model uses TWO
voltage sources, with a shared neutral. One is 120V sin(wt), the
other 120V sin(wt+180) or of alternate polarity connection, if you
like. That is the only way to model that circuit, because that is
what is there. When you center tap it, you now have TWO voltage
sources. Which by the way is exactly what the professor is saying,
you have two sources, 180 out of phase with each other, that's how
you treat it. Do you agree with that? If not, tell us your alternate model.

Problem number 4:

Someone asks why they can't randomly parallel any two receptacles in a house.
My answer is, because you have two 120V voltage sources that are 180 deg
out of phase with each other or of alternate polarity if you like.
If they were of the same phase or polarity, you could parallel them.
Your answer?

On Fri, 3 Aug 2018 07:42:56 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 12:02:12 AM UTC-4, wrote:
On Tue, 24 Jul 2018 08:57:29 -0700 (PDT), trader_4
wrote:

On Tuesday, July 24, 2018 at 11:28:39 AM UTC-4, Bubba wrote:
On 7/24/2018 9:53 AM, trader_4 wrote:
Take two generators built on a single shaft (the same way that three-phase generators are built on a single shaft) so that you get two 120VAC outputs that are 180 degrees out of phase. Would it be reasonable to call this two-phase power?

Bubba, what's your answer?

The transformer for my house has a single phase input.Â* The output of the transformer is single phase as well.Â* I don't have a two-phase generator on my utility pole.

There you have it, typical. Instead of responding to the simple questions
that go to the heart of the matter, just diversion. Others can note that
I responded to your oscilloscope connection question. Note that I also
gave you an opportunity to define for us what makes a system one phase,
two phase, N phase and then explain why residential doesn't meet the
definition of two phase. If you can't define it, then it becomes
arbitrary. Which is kind of what I and the moderator at the forum said,
it's just semantics.


OK lets try this one more time. At my utility I decided to ground one
end of the secondary (L1) instead of the center tap. (like most of the
civilized world according to Bod) I still center tap the transformer
and have 3 buses in my service panel. (lets ignore how you would need
to do overcurrent for now but the answer is a split bus panel).

Everything works exactly the same except I have the neutral
(centertap) bus at 120 above ground and L2 is 240v above ground.
Nothing in your house will notice the difference if you are not using
the EGC (ground) for a current carrying conductor (a violation of
250.6)

Do you still think I have 2 phases?

http://gfretwell.com/electrical/End%...nter%20tap.jpg


Yes, because your neutral is still connected to the center tap.
So, inside the house you will still see two hots at 120V with respect to
the neutral, one 180 deg out of phase with the other, or of alternate
polarity if you like. Hook up a scope, connecting the scope ground
reference to the neutral. The SYSTEM neutral, not some parlor trick
point that I've been accused of using. What do you see? Two hots,
120v, 180 out of phase.

But you can't even do your parlor trick now because the ground on the
scope would be connected to 120v and kaboom.
Who cares what the signal looks like there anyway?
This is quite clearly a single phase source that is 120 and 240 above
ground yet it is wired exactly the same way.
The only thing I did was move where I land the MBJ. It is just easier
to see that in any given instant current is flowing anywhere in the
circuit in exactly the same direction.
If I don't use the center tap to supply 120v loads towards L2
it is actually not a bad way to do things because it would allow
single pole breakers everywhere, That will be important when they
expand GFCI/AFCI to the 240v circuits, I could draw how you would hook
up an existing panel that way if you haven't figured it out by now.
At the end of the day, landing the neutral on the center tap was just
an arbitrary decision by Westinghouse to allay some of the fears of
his "killer" AC.

On 8/2/2018 5:45 PM, trader_4 wrote:
On Thursday, August 2, 2018 at 5:49:48 PM UTC-4, bud-- wrote:
On 8/1/2018 6:43 PM, wrote:

Your problem is you can't step back and look at this as a system. You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.


Trader's source says:
"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."
[I am not "rural" and my distribution is "single phase line to ground".]

Trader's source says that standard practice is that 240/120V systems are
single phase.

Nice hack job Bud. What he said was:

I quoted _exactly_ what he said.
Distribution engineers consider 240/120 to be single phase.


Trader's source suggests they should be 2 phases. There is no reason to
believe anyone but trader agrees.

He says they have been "treated" as single phase, but that what is actually
there are TWO PHASES.

In his opinion.


None of the many people I have met that have worked on 3-phase systems
would call 240/120V systems 2 phases.

I'm not arguing what it's commonly called. Like the engineerig prof,
I'm telling you what's really there from an electrical engineering perspective.

In your opinion.

Manufacturers and people who actually work with multiphase don't agree.

But you can call it whatever you want to if you don't mind problems
communicating with people in the power industry.

On Fri, 3 Aug 2018 07:42:56 -0700 (PDT), trader_4
wrote:

I can do the same with 3 phase, run it into
the house. I'd see one sine wave at 0 deg, one at 120 deg, one at 240 deg,
correct? Rotate the 120 deg coil to 180, what do you see now? It's
a sine wave at 180, correct? Are there still 3 phases there or did
one just disappear? Now remove the 240 phase conductor. Three minus
one is TWO. And what you have left is exactly identical to 240/120
service. Two hots, 180 deg out of phase with each other.

If you connect them together and they are in phase now, you just
created a single phase.
In a series circuit (source) that actually works, you always connect
the positive to the negative and you create a single source.
Take the 9v batteries you were talking about earlier. You said it was
2 sources when I snapped two together in series. Thanks for confirming
what I said because to use your theory, there are actually 12 sources
now because you need 6 cells to get 9v. You just can't easily get to
the 6 in the can. It does not change the fact that once they are all
in series you have to treat them as one source, whether you can
measure each cell or not.

On Fri, 3 Aug 2018 07:27:08 -0700 (PDT), trader_4
wrote:

But I don't need a transformer to define N phase power.
Still waiting for your definition of that. How can you be here arguing
about what something is, but can't define it?

I already did when I took your little test but it is a red herring
anyway.

On Fri, 3 Aug 2018 09:52:21 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 12:40:21 PM UTC-4, bud-- wrote:
On 8/2/2018 5:45 PM, trader_4 wrote:
On Thursday, August 2, 2018 at 5:49:48 PM UTC-4, bud-- wrote:
On 8/1/2018 6:43 PM, wrote:

Your problem is you can't step back and look at this as a system. You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.


Trader's source says:
"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."
[I am not "rural" and my distribution is "single phase line to ground".]

Trader's source says that standard practice is that 240/120V systems are
single phase.

Nice hack job Bud. What he said was:

I quoted _exactly_ what he said.
Distribution engineers consider 240/120 to be single phase.


Trader's source suggests they should be 2 phases. There is no reason to
believe anyone but trader agrees.

He says they have been "treated" as single phase, but that what is actually
there are TWO PHASES.

In his opinion.


None of the many people I have met that have worked on 3-phase systems
would call 240/120V systems 2 phases.

I'm not arguing what it's commonly called. Like the engineerig prof,
I'm telling you what's really there from an electrical engineering perspective.

In your opinion.

It's not a matter of opinion. It's a fact to anyone that's passed
circuits 101. That's why I can apply circuits 101 and answer all those
questions and you and Fretwell can't.

You can't even satisfy Kirchoffs law.
You must have flunked circuits 101.

Someone asks why they can't randomly parallel any two receptacles in a house.
My answer is, because you have two 120V voltage sources that are 180 deg
out of phase with each other or of alternate polarity if you like.
If they were of the same phase or polarity, you could parallel them.
Your answer?


I answered that already You are connecting L1 directly to L2 and the
center tap is not even involved at that time but thanks for showing us
it is ONE SOURCE.

On Friday, August 3, 2018 at 1:33:53 PM UTC-4, wrote:
On Fri, 3 Aug 2018 07:42:56 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 12:02:12 AM UTC-4, wrote:
On Tue, 24 Jul 2018 08:57:29 -0700 (PDT), trader_4
wrote:

On Tuesday, July 24, 2018 at 11:28:39 AM UTC-4, Bubba wrote:
On 7/24/2018 9:53 AM, trader_4 wrote:
Take two generators built on a single shaft (the same way that three-phase generators are built on a single shaft) so that you get two 120VAC outputs that are 180 degrees out of phase. Would it be reasonable to call this two-phase power?

Bubba, what's your answer?

The transformer for my house has a single phase input.Â* The output of the transformer is single phase as well.Â* I don't have a two-phase generator on my utility pole.

There you have it, typical. Instead of responding to the simple questions
that go to the heart of the matter, just diversion. Others can note that
I responded to your oscilloscope connection question. Note that I also
gave you an opportunity to define for us what makes a system one phase,
two phase, N phase and then explain why residential doesn't meet the
definition of two phase. If you can't define it, then it becomes
arbitrary. Which is kind of what I and the moderator at the forum said,
it's just semantics.


OK lets try this one more time. At my utility I decided to ground one
end of the secondary (L1) instead of the center tap. (like most of the
civilized world according to Bod) I still center tap the transformer
and have 3 buses in my service panel. (lets ignore how you would need
to do overcurrent for now but the answer is a split bus panel).

Everything works exactly the same except I have the neutral
(centertap) bus at 120 above ground and L2 is 240v above ground.
Nothing in your house will notice the difference if you are not using
the EGC (ground) for a current carrying conductor (a violation of
250.6)

Do you still think I have 2 phases?

http://gfretwell.com/electrical/End%...nter%20tap.jpg


Yes, because your neutral is still connected to the center tap.
So, inside the house you will still see two hots at 120V with respect to
the neutral, one 180 deg out of phase with the other, or of alternate
polarity if you like. Hook up a scope, connecting the scope ground
reference to the neutral. The SYSTEM neutral, not some parlor trick
point that I've been accused of using. What do you see? Two hots,
120v, 180 out of phase.

But you can't even do your parlor trick now because the ground on the
scope would be connected to 120v and kaboom.


Well that's only because you created a bizarre theoretical situation,
so a common scope that's grounded can't be used. But you can use
a scope that has differential inputs. And I'd again connect it
between the designated SYSTEM NEUTRAL and plot the two hots and
again I'd see two sine waves out of phase by 180. You're the one trying
to perform the parlor trick by not looking at the two 120V voltage
source as they exist and are designed to be used, with the SHARED
NEUTRAL. The shared neutral is the obvious reference point.



Who cares what the signal looks like there anyway?

Electrical engineers analyzing what's there, as I have done consistently
from the start. So did the elect eng prof in his IEEE paper.



This is quite clearly a single phase source that is 120 and 240 above
ground yet it is wired exactly the same way.
The only thing I did was move where I land the MBJ.

And that is why there are still two phases coming from that center
tapped transformer that are 180 out of phase with each other.
You haven't changed what's there or how it works, only what's
connected to earth.



It is just easier
to see that in any given instant current is flowing anywhere in the
circuit in exactly the same direction.
If I don't use the center tap to supply 120v loads towards L2
it is actually not a bad way to do things because it would allow
single pole breakers everywhere, That will be important when they
expand GFCI/AFCI to the 240v circuits,

Say what? If you only have 120V loads on one side of the transformer
then you only have half the total rated power too. So, sure if you're
willing to give up half the power, give up having 240, you can do that.





I could draw how you would hook
up an existing panel that way if you haven't figured it out by now.
At the end of the day, landing the neutral on the center tap was just
an arbitrary decision by Westinghouse to allay some of the fears of
his "killer" AC.

OMG. Having a center tap neutral isn't arbitrary, it's essential to
having 240v and 120v
available. It creates TWO 120V voltage sources that are 180 deg out
of phase with each other, or of alternate polarity, same thing.
Without that, you can't do it. It's not some accident.

And more fundamentally, I gave you the definition of N phase. It
*requires* N voltage sources of differing phase. It explains single
phase, the old 90 deg two phase, a theoretical 179 deg two phase,
180 deg two phase, 3 phase, 100 phase. It's all there in that definition,
without needing to refer to transformers, generators or anything else
and it all is consistent and perfectly logical.

Single phase:

one voltage source sin(wt)


Two phase

two voltage sources sin(wt), sin(wt+P2)


Three phase:

three voltage sources sin(wt), sin(wt+P2), sin(wt+P3)

where P1, P2, P3 are the differing phase angles.

With 240/120, P2 is 180
With the old 90 deg two phase, it was 90


You still refuse to take the simple circuits 101 quiz because you can't
explain the obvious contradictions where your argument quickly falls apart:


Test question one:

Define N phase power?


Test question two:

According to Fretwell, two phase power existed 100 years ago, and it
was over two wires, 90 degrees phase difference. Suppose I run it
over 3 wires instead, with a shared neutral, make it 120V. So,
you have a generator supplying 120V, two coils, one shared neutral.
Would there still be two phases there? (I believe Fretwell said yes)
Your answer?

So now, I run that from the generator into a house, we have three wires,
120V, two phases.
If I change the phase difference to 179 degrees instead of 90
by rotating one coil, are there still two phases? Yes or no?

Now I rotate it to 180 phase difference. Are there still two phases,
yes or no? If you disagree, explain how it's different.


(My answer is yes and the final step above makes it absolutely IDENTICAL
to what you have coming into the house with 240/120. The electrons
are behaving exactly the same. )


Problem number 3

I take 3 phase power with a neutral into a house. One phase is at zero,
one is at 120, one is at 240, correct? I can see them on a scope, yes?

Now I rotate one coil so that instead of 120, it's at 179. Are there
still three phases?

Now I rotate it one degree more, to 180. Are there still 3 phases,
yes or no?

Now take away the 240 phase. How many phases now? If it's not two,
explain why.

And if it is two, then again, it's ELECTRICALLY IDENTICAL TO 240/120 service.
IF you believe it's electrically different, explain why and how it matters
in terms of the behavior of the electrons in the service conductors.


Problem number 4:

Draw the basic circuit model of 240/120 service. My model uses TWO
voltage sources, with a shared neutral. One is 120V sin(wt), the
other 120V sin(wt+180) or of alternate polarity connection, if you
like. That is the only way to model that circuit, because that is
what is there. When you center tap it, you now have TWO voltage
sources. Which by the way is exactly what the professor is saying,
you have two sources, 180 out of phase with each other, that's how
you treat it. Do you agree with that? If not, tell us your alternate model..

Problem number 4:

Someone asks why they can't randomly parallel any two receptacles in a house.
My answer is, because you have two 120V voltage sources that are 180 deg
out of phase with each other or of alternate polarity if you like.
If they were of the same phase or polarity, you could parallel them.
Your answer?


See how simple and consistent it all is? And it doesn't matter if
the voltage sources just exist on paper, if they are generated from
a transformer, a generator, or synthesized electronically from a
DC batter power source.

On Friday, August 3, 2018 at 1:40:40 PM UTC-4, wrote:
On Fri, 3 Aug 2018 07:42:56 -0700 (PDT), trader_4
wrote:

I can do the same with 3 phase, run it into
the house. I'd see one sine wave at 0 deg, one at 120 deg, one at 240 deg,
correct? Rotate the 120 deg coil to 180, what do you see now? It's
a sine wave at 180, correct? Are there still 3 phases there or did
one just disappear? Now remove the 240 phase conductor. Three minus
one is TWO. And what you have left is exactly identical to 240/120
service. Two hots, 180 deg out of phase with each other.

If you connect them together and they are in phase now, you just
created a single phase.

No idea what you're talking about. If you connect two conductors that
are the same voltage and the same phase angle, you've paralleled them,
that's all. There is no potential difference between the two.



And again, why is it that you can't answer those simple questions,
one step at a time? Never mind, I know why.




In a series circuit (source) that actually works, you always connect
the positive to the negative and you create a single source.
Take the 9v batteries you were talking about earlier. You said it was
2 sources when I snapped two together in series. Thanks for confirming
what I said because to use your theory, there are actually 12 sources
now because you need 6 cells to get 9v.

There would be all those additional sources IF YOU PROVIDED A TAP TO
THEM AS PART OF YOUR CIRCUIT. Then you'd have to treat them as separate
voltage sources.



You just can't easily get to
the 6 in the can. It does not change the fact that once they are all
in series you have to treat them as one source, whether you can
measure each cell or not.

It doesn't change the fact that when you tap between batteries or tap
at each cell individually, you now have created separate voltage sources
and that is exactly how they must be treated.
If you haven't, then explain for me the circuit model for 240/120
that doesn't use two 120V voltage sources? I've asked that 6 times
now at least. And in your break into the battery at the cell level, similarly
if those taps inside the battery are connected to power the circuit,
then you have multiple additional separate voltage sources and they
have to be treated that way.

Here are two 3 cell batteries and what you have if you tap and use
all possible points:



________+
C1
________
C2
________
C3
________

2C1
_______
2C2
_______
2C3
_______ -


You have 6 separate voltage sources and there is no other way to draw
that circuit assuming you use all 6 in the circuit and if you're not
then there is obviously no point to tapping them. In the transformer
case, by center tapping it, you've created two 120V voltage sources that
are 180 out of phase or of opposite polarity, same thing.

On Friday, August 3, 2018 at 1:40:40 PM UTC-4, wrote:

Here's another thing that flows beautifully when you understand circuits
101 and apply it consistently. You come into your shop and your assistant
Bob says, I'm going to connect these two conductors together. You look
and he's fooling with some old 90 deg two phase motor, connected to a
two phase power source. You shout, Bob! You can't do that, they are
not the same phase!

Next day he's about to connect the 120 and 240 deg phases of a 3 phase
system. You shout, Bob! You can't do that, they are not the same phase!

Next day he's about to try to parallel two receptacles that are on
different hots in the 240/120 service. In my consistent world, I
shout, Bob! You can't do that, they are not the same phase. You could also
shout you can't do that, they are opposite polarity, which would be
the same thing. What would you shout? Start talking about transformers?
By the time you had just begun your tangled explanation, there would be a
big explosion.

On Fri, 3 Aug 2018 12:46:13 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 1:40:40 PM UTC-4, wrote:

Here's another thing that flows beautifully when you understand circuits
101 and apply it consistently. You come into your shop and your assistant
Bob says, I'm going to connect these two conductors together. You look
and he's fooling with some old 90 deg two phase motor, connected to a
two phase power source. You shout, Bob! You can't do that, they are
not the same phase!

Next day he's about to connect the 120 and 240 deg phases of a 3 phase
system. You shout, Bob! You can't do that, they are not the same phase!

Next day he's about to try to parallel two receptacles that are on
different hots in the 240/120 service. In my consistent world, I
shout, Bob! You can't do that, they are not the same phase. You could also
shout you can't do that, they are opposite polarity, which would be
the same thing. What would you shout? Start talking about transformers?
By the time you had just begun your tangled explanation, there would be a
big explosion.


What colour is the sky in your world ?
... and more importantly -
do you ever have time to gaze at it ?
really.
John T.

On Fri, 3 Aug 2018 12:12:04 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 1:33:53 PM UTC-4, wrote:
On Fri, 3 Aug 2018 07:42:56 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 12:02:12 AM UTC-4, wrote:
On Tue, 24 Jul 2018 08:57:29 -0700 (PDT), trader_4
wrote:

On Tuesday, July 24, 2018 at 11:28:39 AM UTC-4, Bubba wrote:
On 7/24/2018 9:53 AM, trader_4 wrote:
Take two generators built on a single shaft (the same way that three-phase generators are built on a single shaft) so that you get two 120VAC outputs that are 180 degrees out of phase. Would it be reasonable to call this two-phase power?

Bubba, what's your answer?

The transformer for my house has a single phase input.Â* The output of the transformer is single phase as well.Â* I don't have a two-phase generator on my utility pole.

There you have it, typical. Instead of responding to the simple questions
that go to the heart of the matter, just diversion. Others can note that
I responded to your oscilloscope connection question. Note that I also
gave you an opportunity to define for us what makes a system one phase,
two phase, N phase and then explain why residential doesn't meet the
definition of two phase. If you can't define it, then it becomes
arbitrary. Which is kind of what I and the moderator at the forum said,
it's just semantics.


OK lets try this one more time. At my utility I decided to ground one
end of the secondary (L1) instead of the center tap. (like most of the
civilized world according to Bod) I still center tap the transformer
and have 3 buses in my service panel. (lets ignore how you would need
to do overcurrent for now but the answer is a split bus panel).

Everything works exactly the same except I have the neutral
(centertap) bus at 120 above ground and L2 is 240v above ground.
Nothing in your house will notice the difference if you are not using
the EGC (ground) for a current carrying conductor (a violation of
250.6)

Do you still think I have 2 phases?

http://gfretwell.com/electrical/End%...nter%20tap.jpg


Yes, because your neutral is still connected to the center tap.
So, inside the house you will still see two hots at 120V with respect to
the neutral, one 180 deg out of phase with the other, or of alternate
polarity if you like. Hook up a scope, connecting the scope ground
reference to the neutral. The SYSTEM neutral, not some parlor trick
point that I've been accused of using. What do you see? Two hots,
120v, 180 out of phase.

But you can't even do your parlor trick now because the ground on the
scope would be connected to 120v and kaboom.


Well that's only because you created a bizarre theoretical situation,
so a common scope that's grounded can't be used. But you can use
a scope that has differential inputs. And I'd again connect it
between the designated SYSTEM NEUTRAL and plot the two hots and
again I'd see two sine waves out of phase by 180. You're the one trying
to perform the parlor trick by not looking at the two 120V voltage
source as they exist and are designed to be used, with the SHARED
NEUTRAL. The shared neutral is the obvious reference point.


There is no "common scope" that isn't grounded.
Certainly you can cut off the ground pin but the case of the scope
will be at 120v in this scenario.

Who cares what the signal looks like there anyway?

Electrical engineers analyzing what's there, as I have done consistently
from the start. So did the elect eng prof in his IEEE paper.



This is quite clearly a single phase source that is 120 and 240 above
ground yet it is wired exactly the same way.
The only thing I did was move where I land the MBJ.

And that is why there are still two phases coming from that center
tapped transformer that are 180 out of phase with each other.
You haven't changed what's there or how it works, only what's
connected to earth.

Not really. It is a single phase that starts 0-120 and continues
120-240.
The reality is the current flow is exactly the same but it eliminates
that confusion about one being opposite of the other.

It is just easier
to see that in any given instant current is flowing anywhere in the
circuit in exactly the same direction.
If I don't use the center tap to supply 120v loads towards L2
it is actually not a bad way to do things because it would allow
single pole breakers everywhere, That will be important when they
expand GFCI/AFCI to the 240v circuits,

Say what? If you only have 120V loads on one side of the transformer
then you only have half the total rated power too. So, sure if you're
willing to give up half the power, give up having 240, you can do that.

Not really an issue since most of the load in an "all electric" house
is 240v. That became very apparent to me when I was running on a
generator.
I did not turn off any 120v breakers and the load was still
insignificant. I couldn't use many of the 240v loads, even with the
120 breakers off (no dryer, no water heater, no oven, no A/C and only
one burner at a time on the cook top )
In that arrangement 240 is right there too, on a single pole breaker
and single pole switching.
Bod has that in his house right now as does most of the non, North
American world.




I could draw how you would hook
up an existing panel that way if you haven't figured it out by now.
At the end of the day, landing the neutral on the center tap was just
an arbitrary decision by Westinghouse to allay some of the fears of
his "killer" AC.

OMG. Having a center tap neutral isn't arbitrary, it's essential to
having 240v and 120v
available. It creates TWO 120V voltage sources that are 180 deg out
of phase with each other, or of alternate polarity, same thing.
Without that, you can't do it. It's not some accident.

The center tap is necessary but not grounding it.




You still refuse to take the simple circuits 101 quiz because you can't
explain the obvious contradictions where your argument quickly falls apart:

I took your little quiz. Read the notes

On Friday, August 3, 2018 at 3:56:39 PM UTC-4, wrote:
On Fri, 3 Aug 2018 12:46:13 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 1:40:40 PM UTC-4, wrote:

Here's another thing that flows beautifully when you understand circuits
101 and apply it consistently. You come into your shop and your assistant
Bob says, I'm going to connect these two conductors together. You look
and he's fooling with some old 90 deg two phase motor, connected to a
two phase power source. You shout, Bob! You can't do that, they are
not the same phase!

Next day he's about to connect the 120 and 240 deg phases of a 3 phase
system. You shout, Bob! You can't do that, they are not the same phase!

Next day he's about to try to parallel two receptacles that are on
different hots in the 240/120 service. In my consistent world, I
shout, Bob! You can't do that, they are not the same phase. You could also
shout you can't do that, they are opposite polarity, which would be
the same thing. What would you shout? Start talking about transformers?
By the time you had just begun your tangled explanation, there would be a
big explosion.


What colour is the sky in your world ?
.. and more importantly -
do you ever have time to gaze at it ?
really.
John T.

I take that to mean you can't give a definition of N phase power either.

On Fri, 3 Aug 2018 12:28:05 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 1:40:40 PM UTC-4, wrote:
On Fri, 3 Aug 2018 07:42:56 -0700 (PDT), trader_4
wrote:

I can do the same with 3 phase, run it into
the house. I'd see one sine wave at 0 deg, one at 120 deg, one at 240 deg,
correct? Rotate the 120 deg coil to 180, what do you see now? It's
a sine wave at 180, correct? Are there still 3 phases there or did
one just disappear? Now remove the 240 phase conductor. Three minus
one is TWO. And what you have left is exactly identical to 240/120
service. Two hots, 180 deg out of phase with each other.

If you connect them together and they are in phase now, you just
created a single phase.

No idea what you're talking about. If you connect two conductors that
are the same voltage and the same phase angle, you've paralleled them,
that's all. There is no potential difference between the two.

Yes bet you are talking about 2 sources that are already connected in
series in phase with each other. Then you want to simultaneously want
to make a parallel connection .... Kaboom.


And again, why is it that you can't answer those simple questions,
one step at a time? Never mind, I know why.

.... I have many times. You just refuse to accept my answer.


In a series circuit (source) that actually works, you always connect
the positive to the negative and you create a single source.
Take the 9v batteries you were talking about earlier. You said it was
2 sources when I snapped two together in series. Thanks for confirming
what I said because to use your theory, there are actually 12 sources
now because you need 6 cells to get 9v.

There would be all those additional sources IF YOU PROVIDED A TAP TO
THEM AS PART OF YOUR CIRCUIT. Then you'd have to treat them as separate
voltage sources.

You are just being silly now. If you can see it, it doesn't exist?
No wonder the professor needs to resort to such convoluted logic to
explain a simple thing to you snowflakes.

I am OUT

On 08/02/2018 12:08 PM, wrote:

[snip]

If this was a DC supply, like our two batteries in series, are you
still going to say the current suddenly changed directions at the
point where they connect?

Such a power supply (like 2 batteries in series, with the point between
them grounded) IS described as having two outputs (for example +12V and
-12V).

If the supply included a switch that exchanged the outputs periodically,
you'd have phase.

--
Mark Lloyd
http://notstupid.us/

"Many demons are in woods, in waters, in wildernesses, and in dark
poolly places ready to hurt...people." [Martin Luther]

On 08/02/2018 01:40 PM, Tres DaFo wrote:
On 8/2/2018 1:49 PM, Mark Lloyd wrote:

This isn't the first time I've seen a disagreement where both sides
are right.

Not so fast, Mark!

The problem is when using trader_4's parlor trick definition, virtually
every residential electrical service installed in the US is in violation
of electrical code because the panels are only listed for single-phase
service.

Strange, the argument was about what to CALL it. IIRC, nobody said
anything about wiring it differently.

--
Mark Lloyd
http://notstupid.us/

"Many demons are in woods, in waters, in wildernesses, and in dark
poolly places ready to hurt...people." [Martin Luther]

On Thursday, August 2, 2018 at 1:14:17 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:42:04 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:51:03 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:59:37 -0700 (PDT), trader_4
wrote:

If they are the same phase, same voltage, then there is no voltage

Now you are confusing "phase" with difference in potential.

Not confusing anything at all. If two conductors are of the same phase
and same voltage, then there is no potential difference between them.



There is
always a difference of potential in any circuit or current will not
flow. Mr Ohm teaches us that. That is even true with DC with no phase
at all.

There isn't a difference in potential and no current flows if I connect
two conductors that are the same phase and voltage. That's why I can
parallel receptacles in a house that are on the same phase and nothing
happens. If I try to parallel ones that are on the two different 120V
phases, then Kapow!

You are over complicating a simple fact. You are connecting line 1 to
line 2, the two ends of the secondary. Where the ground happens to be
or even the fact that there is a center tap does not enter into it at
all at that point.

It doesn't matter whether the source is a transformer, a generator, or
a electronically synthesized from a battery. What matters is that you
have two hots that are 180 deg out of phase with respect to the neutral.
Knowing that is all that I need to know to determine what they are and
that they cannot be connected together.






Ungrounded conductors do not necessarily mean phase.

I never said otherwise.

OK then, there are 2 ungrounded conductors coming into your house, not
2 phases.

Do you agree a single untapped secondary grounded at one end like
Europe would be single phase? (2xx volts and ground no center tap)

Yes, because then it's ONE voltage source. When you center tap it
you create TWO separate voltage sources tied together

No there is still ONE source, that happens to be divided., It is still
just one secondary to one transformer.

I've asked many times now. Draw us the simple first week of circuits 101
circuit diagram that represents what we have going into the house.
Do it without using two 120 volt voltage sources. I've given you mine:

One 120V voltage source sin(wt)

One 120V voltage source sin(st+180)

Show us how you do it with just ONE voltage source. You can't.

On Friday, August 3, 2018 at 2:21:30 PM UTC-4, wrote:
On Fri, 3 Aug 2018 09:52:21 -0700 (PDT), trader_4
wrote:

On Friday, August 3, 2018 at 12:40:21 PM UTC-4, bud-- wrote:
On 8/2/2018 5:45 PM, trader_4 wrote:
On Thursday, August 2, 2018 at 5:49:48 PM UTC-4, bud-- wrote:
On 8/1/2018 6:43 PM, wrote:

Your problem is you can't step back and look at this as a system. You
are locked up inside the panelboard enclosure with tunnel vision
focused on the main bonding jumper like that is the center of the
universe.
If you look at the stars from earth, it is easy to think they revolve
around the earth.


Trader's source says:
"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."
[I am not "rural" and my distribution is "single phase line to ground".]

Trader's source says that standard practice is that 240/120V systems are
single phase.

Nice hack job Bud. What he said was:

I quoted _exactly_ what he said.
Distribution engineers consider 240/120 to be single phase.


Trader's source suggests they should be 2 phases. There is no reason to
believe anyone but trader agrees.

He says they have been "treated" as single phase, but that what is actually
there are TWO PHASES.

In his opinion.


None of the many people I have met that have worked on 3-phase systems
would call 240/120V systems 2 phases.

I'm not arguing what it's commonly called. Like the engineerig prof,
I'm telling you what's really there from an electrical engineering perspective.

In your opinion.

It's not a matter of opinion. It's a fact to anyone that's passed
circuits 101. That's why I can apply circuits 101 and answer all those
questions and you and Fretwell can't.

You can't even satisfy Kirchoffs law.
You must have flunked circuits 101.


Show us where anything I did violates it. And I can draw you the circuit
diagram that models the 240/120v service. It requires TWO 120v voltage
sources:

One 120v sin(wt)
One 120v sin(wt+180)

Or two connected with opposite polarity, which is the same thing as 180
deg phase difference. The two 120v voltage sources are connected together
at one end, sharing the neutral. THAT is your service. Where is your
circuit diagram that uses only one voltage source? You can't do it,
because the center tapped transformer becomes TWO separate voltage sources.





Someone asks why they can't randomly parallel any two receptacles in a house.
My answer is, because you have two 120V voltage sources that are 180 deg
out of phase with each other or of alternate polarity if you like.
If they were of the same phase or polarity, you could parallel them.
Your answer?


I answered that already You are connecting L1 directly to L2 and the
center tap is not even involved at that time but thanks for showing us
it is ONE SOURCE.


Funny how my definition of N phase power covers all phases, including
this case. You can't connect the two hots together because they are
differing phases. And one more time, it doesn't matter where they came
from. They could come directly from a generator. What about that?
The emergency power kicks in, there is no transformer. Or I power it
via a UPS, electronically synthesizing two 120V waveforms that are 180
apart. That the two hots are out of phase by 180 covers it ALL.

On Friday, August 3, 2018 at 4:02:55 PM UTC-4, wrote:


But you can't even do your parlor trick now because the ground on the
scope would be connected to 120v and kaboom.


Well that's only because you created a bizarre theoretical situation,
so a common scope that's grounded can't be used. But you can use
a scope that has differential inputs. And I'd again connect it
between the designated SYSTEM NEUTRAL and plot the two hots and
again I'd see two sine waves out of phase by 180. You're the one trying
to perform the parlor trick by not looking at the two 120V voltage
source as they exist and are designed to be used, with the SHARED
NEUTRAL. The shared neutral is the obvious reference point.


There is no "common scope" that isn't grounded.
Certainly you can cut off the ground pin but the case of the scope
will be at 120v in this scenario.

Sigh.....

https://www.picotech.com/oscilloscop...-4444-overview






Who cares what the signal looks like there anyway?

Electrical engineers analyzing what's there, as I have done consistently
from the start. So did the elect eng prof in his IEEE paper.



This is quite clearly a single phase source that is 120 and 240 above
ground yet it is wired exactly the same way.
The only thing I did was move where I land the MBJ.

And that is why there are still two phases coming from that center
tapped transformer that are 180 out of phase with each other.
You haven't changed what's there or how it works, only what's
connected to earth.

Not really. It is a single phase that starts 0-120 and continues
120-240.
The reality is the current flow is exactly the same but it eliminates
that confusion about one being opposite of the other.

The voltage on one hot is the opposite of the voltage on the other hot
with respect to the neutral. We also call that 180 deg phase difference.
And it works whether the TWO 120V voltage sources are from two coils
on a transformer, directly from a generator, or synthesized completely
electronically from a battery. It's their phase relationship, voltage
and current capacity that completely define them, not how they were
created. The electrons don't care, the appliances don't care.





It is just easier
to see that in any given instant current is flowing anywhere in the
circuit in exactly the same direction.
If I don't use the center tap to supply 120v loads towards L2
it is actually not a bad way to do things because it would allow
single pole breakers everywhere, That will be important when they
expand GFCI/AFCI to the 240v circuits,

Say what? If you only have 120V loads on one side of the transformer
then you only have half the total rated power too. So, sure if you're
willing to give up half the power, give up having 240, you can do that.

Not really an issue since most of the load in an "all electric" house
is 240v.

Well, it would be a major change to the specification of the service,
cutting the power available at 120V in half. How much that matters
depends entirely on what all you're powering. Most houses, I would
agree they don't have enough 120V loads for it to matter.





That became very apparent to me when I was running on a
generator.
I did not turn off any 120v breakers and the load was still
insignificant. I couldn't use many of the 240v loads, even with the
120 breakers off (no dryer, no water heater, no oven, no A/C and only
one burner at a time on the cook top )
In that arrangement 240 is right there too, on a single pole breaker
and single pole switching.
Bod has that in his house right now as does most of the non, North
American world.




I could draw how you would hook
up an existing panel that way if you haven't figured it out by now.
At the end of the day, landing the neutral on the center tap was just
an arbitrary decision by Westinghouse to allay some of the fears of
his "killer" AC.

OMG. Having a center tap neutral isn't arbitrary, it's essential to
having 240v and 120v
available. It creates TWO 120V voltage sources that are 180 deg out
of phase with each other, or of alternate polarity, same thing.
Without that, you can't do it. It's not some accident.

The center tap is necessary but not grounding it.


Why are we even talking about what gets grounded? I didn't bring it
up, you did. You wanted to earth one end of the transformer instead
of the center.







You still refuse to take the simple circuits 101 quiz because you can't
explain the obvious contradictions where your argument quickly falls apart:

I took your little quiz. Read the notes

I'll be looking for it.

On Friday, August 3, 2018 at 4:51:44 PM UTC-4, Mark Lloyd wrote:
On 08/02/2018 01:40 PM, Tres DaFo wrote:
On 8/2/2018 1:49 PM, Mark Lloyd wrote:

This isn't the first time I've seen a disagreement where both sides
are right.

Not so fast, Mark!

The problem is when using trader_4's parlor trick definition, virtually
every residential electrical service installed in the US is in violation
of electrical code because the panels are only listed for single-phase
service.

Strange, the argument was about what to CALL it. IIRC, nobody said
anything about wiring it differently.


Thank you. I said that in my first post.

On Friday, August 3, 2018 at 4:44:52 PM UTC-4, Mark Lloyd wrote:
On 08/02/2018 12:08 PM, wrote:

[snip]

If this was a DC supply, like our two batteries in series, are you
still going to say the current suddenly changed directions at the
point where they connect?

Such a power supply (like 2 batteries in series, with the point between
them grounded) IS described as having two outputs (for example +12V and
-12V).



Fretwell seems to think that providing additional taps doesn't create
additional voltage sources. I keep asking for him to give us the
circuit model for 240/120 service that doesn't use TWO 120V voltage
sources. And that is exactly how the elect engineering professor
drew the circuit, with two voltage sources.

On Friday, August 3, 2018 at 4:02:55 PM UTC-4, wrote:


I took your little quiz. Read the notes

If you took it, where is it? I don't see it here.

Here it is again:

Problem 1:


Define N phase power?


Problem two:

According to Fretwell, two phase power existed 100 years ago, and it
was over two wires, 90 degrees phase difference. Suppose I run it
over 3 wires instead, with a shared neutral, make it 120V. So,
you have a generator supplying 120V, two coils, one shared neutral.
Would there still be two phases there?
(I believe Fretwell said yes)
Your answer?

So now, I run that from the generator into a house, we have three wires,
120V, two phases.
If I change the phase difference to 179 degrees instead of 90
by rotating one coil, are there still two phases? Yes or no?

Now I rotate it to 180 phase difference. Are there still two phases,
yes or no? If you disagree, explain how it's different, how there
suddenly there are not two phases there.


(My answer is yes and the final step above makes it absolutely IDENTICAL
to what you have coming into the house with 240/120. The electrons
are behaving exactly the same. )


Problem number 3

I take 3 phase power with a neutral into a house. One phase is at zero,
one is at 120, one is at 240, correct? I can see them on a scope, yes?

Now I rotate one coil so that instead of 120, it's at 179. Are there
still three phases?

Now I rotate it one degree more, to 180. Are there still 3 phases,
yes or no?

Now take away the 240 phase. How many phases now? If it's not two,
explain why.

And if it is two, then again, it's now ELECTRICALLY IDENTICAL TO 240/120 service.
IF you believe it's electrically different, explain why and how it matters
in terms of the behavior of the electrons in the service conductors.


Problem number 4:

Draw the basic circuit model of 240/120 service. My model uses TWO
voltage sources, with a shared neutral. One is 120V sin(wt), the
other 120V sin(wt+180) or of alternate polarity connection, if you
like. That is the only way to model that circuit, because that is
what is there. When you center tap it, you now have TWO voltage
sources. Which by the way is exactly what the professor is saying,
you have two sources, 180 out of phase with each other, that's how
you treat it. Do you agree with that? If not, tell us your alternate model.

Problem number 4:

Someone asks why they can't randomly parallel any two receptacles in a house.
My answer is, because you have two 120V voltage sources that are 180 deg
out of phase with each other or of alternate polarity if you like.
You can only parallel ones that are of the same phase or polarity.

Your answer?

On Sat, 4 Aug 2018 07:27:39 -0700 (PDT), trader_4
wrote:

On Thursday, August 2, 2018 at 1:14:17 PM UTC-4, wrote:
On Thu, 2 Aug 2018 08:42:04 -0700 (PDT), trader_4
wrote:

On Wednesday, August 1, 2018 at 8:51:03 PM UTC-4, wrote:
On Wed, 1 Aug 2018 12:59:37 -0700 (PDT), trader_4
wrote:

If they are the same phase, same voltage, then there is no voltage

Now you are confusing "phase" with difference in potential.

Not confusing anything at all. If two conductors are of the same phase
and same voltage, then there is no potential difference between them.



There is
always a difference of potential in any circuit or current will not
flow. Mr Ohm teaches us that. That is even true with DC with no phase
at all.

There isn't a difference in potential and no current flows if I connect
two conductors that are the same phase and voltage. That's why I can
parallel receptacles in a house that are on the same phase and nothing
happens. If I try to parallel ones that are on the two different 120V
phases, then Kapow!

You are over complicating a simple fact. You are connecting line 1 to
line 2, the two ends of the secondary. Where the ground happens to be
or even the fact that there is a center tap does not enter into it at
all at that point.

It doesn't matter whether the source is a transformer, a generator, or
a electronically synthesized from a battery. What matters is that you
have two hots that are 180 deg out of phase with respect to the neutral.
Knowing that is all that I need to know to determine what they are and
that they cannot be connected together.

It has noting to do with the neutral an any way. You simply can't
connect the opposite ends of a voltage source together without an
appropriate load, whether it is a battery, a generator, a transformer
or a solar cell.

On Sat, 4 Aug 2018 07:47:06 -0700 (PDT), trader_4
wrote:




Who cares what the signal looks like there anyway?

Electrical engineers analyzing what's there, as I have done consistently
from the start. So did the elect eng prof in his IEEE paper.



This is quite clearly a single phase source that is 120 and 240 above
ground yet it is wired exactly the same way.
The only thing I did was move where I land the MBJ.

And that is why there are still two phases coming from that center
tapped transformer that are 180 out of phase with each other.
You haven't changed what's there or how it works, only what's
connected to earth.

Not really. It is a single phase that starts 0-120 and continues
120-240.
The reality is the current flow is exactly the same but it eliminates
that confusion about one being opposite of the other.

The voltage on one hot is the opposite of the voltage on the other hot
with respect to the neutral.

One "hot" is 240 volts away from the other one whether you center tap
the secondary or not.
Do you agree with that?

On Sat, 4 Aug 2018 08:16:34 -0700 (PDT), trader_4
wrote:

So now, I run that from the generator into a house, we have three wires,
120V, two phases.
If I change the phase difference to 179 degrees instead of 90
by rotating one coil, are there still two phases? Yes or no?

It is things like this that keep me from taking you seriously,

If you have 2 windings connected end to end and they are out of phase,
You have THREE PHASE DELTA, not two phase. The way you get two phase
is to connect one transformer to the center tap of another. That will
either look like a cross or a tee.
Google up "delta vee", "Scott tee" and stop sounding ignorant of the
facts.
You also can't have a phase relationship more than 180 degrees (as you
have theorized) because the phase rotation would change and we would
be back to the complementary angle going the other way.
I really suspect it would stabilize back to 120 degrees but I have
never seen anyone try it, I doubt your professor has either in real
life.