On Sat, 23 Nov 2013 10:17:08 +1100, John G wrote:

If you had any understanding of electricity you could understand that
the GROUND is not part of the circuit.
It is there to keep all the parts of the system at the same reference
potential.

Well, I *thought* I understood electricity, in that without a "loop",
there would be no current.

What I *think* is the real answer, albeit it's hard grasp because the
earth itself is so huge, is that there *is* a loop with the power
company.

The loop starts with electrons being pulled from the ground, which
then go over the three hot wires where one of those three hot phases
is sent to your transformer primary, where the second lead of the
transformer primary goes into the ground, which completes the
circuit.

The fact that the earth is so huge that this completion of the
circuit isn't even noticed back at the power company doesn't mean
there isn't a loop.

It's just that the loop is one huge chunk of conductor (namely,
the earth itself).

But, it's my understanding that this still completes the loop.

For example, if I lifted the transformer primary wire so that
it no longer contacted the ground, that would immediately
stop the current that flows back into the ground, hence
breaking the loop.

Right?

On Sat, 23 Nov 2013 10:17:08 +1100, John G wrote:

No current flows in around or thru the ground if all the conductors are
installed to code. :-Z

That's not how I understand it.

Even though the ground is so big that even all the nuclear power plants
in the world pumping electrons into the ground couldn't change its
potential, that doesn't mean that the ground doesn't complete the
circuit.

If the power company chose any other conductor other than "the" ground,
then they would have to have a wire for each phase distributed.

Since the power company chose to use "the" ground as "their" ground,
the way I understand it, "my" ground is connected to "their" ground,
so, the electron that flows into the primary of my transformer came
from the ground at the power plant, and it goes back into the ground
at my house, to (theoretically) make it back to the power plant.

Of course, the ground is so big that it's like pouring a glass of
water into the ocean, where that molecule eventually will make it
around the earth - but the immensity of the ground should not be
construed as implying there isn't a loop from the earth at the
power company to the wires to my transformer primary to the earth
at my transformer.

At least that's how *I* understand the typical mains power in the US.

On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:

From Professor Cardell's web page at

http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

"There are two wires running out of the transformer and three wires running to the house.
The two from the transformer are insulated, and the third one is bare. The bare wire is the ground wire.
The two insulated wires each carry 120 volts, but they are 180 degrees out of phase so the difference between them is 240 volts."

Why are all three of mine insulated?
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:

From Professor Cardell's web page at
http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

"There are two wires running out of the transformer and three wires
running to the house. The two from the transformer are insulated, and
the third one is bare. The bare wire is the ground wire. The two insulated
wires each carry 120 volts, but they are 180 degrees out of phase so the
difference between them is 240 volts."

Why are all three of mine insulated?
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

Danny D'Amico explained on 25/11/2013 :
On Sat, 23 Nov 2013 10:17:08 +1100, John G wrote:

No current flows in around or thru the ground if all the conductors are
installed to code. :-Z

That's not how I understand it.

Even though the ground is so big that even all the nuclear power plants
in the world pumping electrons into the ground couldn't change its
potential, that doesn't mean that the ground doesn't complete the
circuit.

If the power company chose any other conductor other than "the" ground,
then they would have to have a wire for each phase distributed.

Since the power company chose to use "the" ground as "their" ground,
the way I understand it, "my" ground is connected to "their" ground,
so, the electron that flows into the primary of my transformer came
from the ground at the power plant, and it goes back into the ground
at my house, to (theoretically) make it back to the power plant.

Of course, the ground is so big that it's like pouring a glass of
water into the ocean, where that molecule eventually will make it
around the earth - but the immensity of the ground should not be
construed as implying there isn't a loop from the earth at the
power company to the wires to my transformer primary to the earth
at my transformer.

At least that's how *I* understand the typical mains power in the US.
You just do not understand.


AGAIN I tell you the ground has no part in the supply of power it all
happens on the wires and the ground is just the background.

Please got to school and learn the basic principles. :-?

--
John G

Danny D'Amico formulated on Monday :
On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:

From Professor Cardell's web page at
http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

"There are two wires running out of the transformer and three wires
running to the house. The two from the transformer are insulated, and
the third one is bare. The bare wire is the ground wire. The two insulated
wires each carry 120 volts, but they are 180 degrees out of phase so the
difference between them is 240 volts."

Why are all three of mine insulated?
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif

Insulated or not has no bearing on how it all works it is only where
the ends are connected that affects the outcome.

Please go to school and learn the basic principles of electricity :-@

--
John G

On Monday, November 25, 2013 3:07:59 AM UTC-5, Danny D'Amico wrote:
On Fri, 22 Nov 2013 05:58:03 -0800, wrote:



It's referring to where the two legs/phases show up in the panel.

But, I'm not sure what AB means either. You need to define what

the perspective is.



I'm going to make a stab at *guessing* what A & B are in my

main breaker panel.



Is this correct?

http://farm8.staticflickr.com/7294/1...3c991e33_o.png

Yes, they alternate vertically.

On Monday, November 25, 2013 2:50:25 AM UTC-5, Danny D'Amico wrote:
On Fri, 22 Nov 2013 23:11:08 -0600, Nightcrawler® wrote:



The example given in your .png showed AB....AB on the left,

and BA....BA on the right. This is a lay-out that makes zero

sense and would require some goofy bus work to accomplish.



I wish whoever kept posting that PDF would have known that

and not posted it then, because that's what we were going on.



So, the top two bus tabs, inline from left to right are phase A.

The next row down will be phase B, inline from left to right.



Makes sense.



A 2-pole breaker will take up two spaces, top

to bottom and will give you both an A and a B phase.



I like that we can *see* that, given there are two hots coming

out of the 240V breaker, so, it *must* be phase A & B.

http://farm6.staticflickr.com/5484/1...a8b636fc_o.gif



Meaning that if you where to have black and red wires denoting

phasing, the black would go on A, and the red would go on B.



This is an interesting observation.



Black is always A, Red is always B



Ah. This is news to me. So, all reds, in the breaker panel, would

be B then. But, isn't this red wire on A?

http://farm4.staticflickr.com/3696/1...38f77b97_o.gif



Here's a further-out view of that same breaker:

http://farm4.staticflickr.com/3794/1...cfcb99fb_o.gif



Since the red is on top, isn't that phase A (and not phase B)?

Which one you call A and which B is arbitrary. What matters
is that you wind up with the phases alternating on the breaker
slots, vertically. That way with a double pole breaker, you
get 240V. If they didn't alternate, you'd get 0v.

On Monday, November 25, 2013 3:18:49 AM UTC-5, Danny D'Amico wrote:
On Sat, 23 Nov 2013 10:17:08 +1100, John G wrote:



No current flows in around or thru the ground if all the conductors are

installed to code. :-Z



That's not how I understand it.



Even though the ground is so big that even all the nuclear power plants

in the world pumping electrons into the ground couldn't change its

potential, that doesn't mean that the ground doesn't complete the

circuit.



If the power company chose any other conductor other than "the" ground,

then they would have to have a wire for each phase distributed.



Since the power company chose to use "the" ground as "their" ground,

the way I understand it, "my" ground is connected to "their" ground,

so, the electron that flows into the primary of my transformer came

from the ground at the power plant, and it goes back into the ground

at my house, to (theoretically) make it back to the power plant.



Of course, the ground is so big that it's like pouring a glass of

water into the ocean, where that molecule eventually will make it

around the earth - but the immensity of the ground should not be

construed as implying there isn't a loop from the earth at the

power company to the wires to my transformer primary to the earth

at my transformer.



At least that's how *I* understand the typical mains power in the US.

Most of the current doesn't have to flow back via the earth. You
have a transformer that is connected on one phase of the primary.
It serves several houses. Further down the street, there is another
transformer, it is on a different phase. Even further down, there
is another transformer on the third phase. The other sides of all
those transformers are all tied together on the primary neutral.
If those loads are equal, then the sum of the currents in the
neutral is zero, you have a balanced wye configuration and the only
net current flow is in the 3 primary phase wires.

On Monday, November 25, 2013 5:24:40 AM UTC-5, John G wrote:
Danny D'Amico formulated on Monday :

On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:



From Professor Cardell's web page at

http://www.science.smith.edu/~jcarde...ecPwr_HSW.html



"There are two wires running out of the transformer and three wires

running to the house. The two from the transformer are insulated, and

the third one is bare. The bare wire is the ground wire. The two insulated

wires each carry 120 volts, but they are 180 degrees out of phase so the

difference between them is 240 volts."



Why are all three of mine insulated?

http://farm3.staticflickr.com/2886/1...21cf1404_o.gif



Insulated or not has no bearing on how it all works it is only where

the ends are connected that affects the outcome.



Please go to school and learn the basic principles of electricity :-@



--

John G

He has a legitimate question. It's not clear to me why sometimes the
neutral service wire is insulated, like he has. I know it's also many
times uninsulated as well.

On 11/25/2013 08:31 AM, wrote:
[snip]

He has a legitimate question. It's not clear to me why sometimes the
neutral service wire is insulated, like he has. I know it's also many
times uninsulated as well.


I'm not an expert nor do I play one on usenet but...

IIRC, current carrying (line and neutral) conductors in a conduit must be insulated.

This is usenet and if I'm wrong I'll be corrected shortly. ;-)

On Monday, November 25, 2013 3:13:56 AM UTC-5, Danny D'Amico wrote:
On Sat, 23 Nov 2013 10:17:08 +1100, John G wrote:



If you had any understanding of electricity you could understand that

the GROUND is not part of the circuit.

It is there to keep all the parts of the system at the same reference

potential.



Well, I *thought* I understood electricity, in that without a "loop",

there would be no current.



What I *think* is the real answer, albeit it's hard grasp because the

earth itself is so huge, is that there *is* a loop with the power

company.



The loop starts with electrons being pulled from the ground, which

then go over the three hot wires where one of those three hot phases

is sent to your transformer primary, where the second lead of the

transformer primary goes into the ground, which completes the

circuit.

I do want to thank those who responded to my initial question about how the center tap gets referenced to ground.

I think we get sidetracked with the use of phase to mean two different things. What if you put ground on the bottom of the secondary instead of the center? Hee, hee.

But, at the risk of another rabbit hole, electrons don't actually get pulled from ground and sent to your house, unless you have a DC supply. In AC, electrons merely bounce back and forth a short distance, like a millionth of a meter. The wave travels, but not the electrons. IIRC.

On 11/25/2013 2:18 AM, Danny D'Amico wrote:
On Sat, 23 Nov 2013 10:17:08 +1100, John G wrote:

No current flows in around or thru the ground if all the conductors are
installed to code. :-Z

That's not how I understand it.

Even though the ground is so big that even all the nuclear power plants
in the world pumping electrons into the ground couldn't change its
potential, that doesn't mean that the ground doesn't complete the
circuit.

The earth does not complete the circuit. Wires complete the circuit.

The electrons that flow are in the wire.

If you had DC, an electron flowing out one end of a wire would be
matched by an electron flowing in the other end. A single electron may
not move very far, it can be replaced by another electron. A property of
a metal is that there are electrons that are not tightly bound that can
migrate.

With AC, electrons move in one direction, then the other.


If the power company chose any other conductor other than "the" ground,
then they would have to have a wire for each phase distributed.

The do have a wire for any intentional electrical path.


Since the power company chose to use "the" ground as "their" ground,
the way I understand it, "my" ground is connected to "their" ground,
so, the electron that flows into the primary of my transformer came
from the ground at the power plant, and it goes back into the ground
at my house, to (theoretically) make it back to the power plant.

Since early power distribution days there is a metal connection for the
entire path. Earth is not an intentional path.


Of course, the ground is so big that it's like pouring a glass of
water into the ocean, where that molecule eventually will make it
around the earth - but the immensity of the ground should not be
construed as implying there isn't a loop from the earth at the
power company to the wires to my transformer primary to the earth
at my transformer.

The earth is not used as an intentional path.

The connection to earth is used to limit the voltage between the wires
and the earth. The earth is also a sink for lightning and similar
events, and is used to trip overcurrent protection with crossed wires.

The earth is not allowed to be a path to trip a circuit breaker in your
house if there is a short between a hot wire and ground at, for
instance, a drill. The short circuit current goes through the N-G bond
at the service and returns to the utility transformer through the
service neutral. The earth is not allowed to be the path because it is
not an effective path.


At least that's how *I* understand the typical mains power in the US.

Rather flawed.

Bud, until recently I would have agreed with you. But, whomever wrote this web page obviously knows something about electric power generation and distribution and seems to disagree:

http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

Look at the bottom paragraph in the section entitled "The Power Plant: Three Phase Power" where it says:


And what about this "ground," as mentioned above? The power company essentially uses the earth as one of the wires in the power system. The earth is a pretty good conductor and it is huge, so it makes a good return path for electrons. (Car manufacturers do something similar; they use the metal body of the car as one of the wires in the car's electrical system and attach the negative pole of the battery to the car's body.) "Ground" in the power distribution grid is literally "the ground" that's all around you when you are walking outside. It is the dirt, rocks, groundwater, etc., of the earth.


I don't think he could have said it any clearer.

On Mon, 25 Nov 2013 08:21:10 +0000 (UTC), Danny D'Amico
wrote:

On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:

From Professor Cardell's web page at

http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

"There are two wires running out of the transformer and three wires running to the house.
The two from the transformer are insulated, and the third one is bare. The bare wire is the ground wire.
The two insulated wires each carry 120 volts, but they are 180 degrees out of phase so the difference between them is 240 volts."

Why are all three of mine insulated?
http://farm3.staticflickr.com/2886/1...21cf1404_o.gif


First of all, in North America, the typical p[ower supply is NOT 2
phase. It is center tapped single phase. You have a line1, a line2 and
a neutral - the neutral being shared between the two lines. If the
load is ballanced between the 2 "sides" there is no current in the
neutral. The neutral is regerenced to ground for safety reasons.

In early reural electrification in the USA, single wire distribution
was used - using "earth return" It worked, but was fraught with
problems, and is virtually unheard of today..

Today's power distribution is 3 phase - with each phase feeding a
separate distribution transformer - which has a center tapped
secondary for residential power. 3 phase is supplied for industry and
some multi-unit residential buildings which run 120/208 instead of
120/240. This is because 3 phase power is 120 degrees phase to phase.
because the generating system IS 3 phase, there can not be 2 "phases"
180 degrees apart.

Line1 and Line2 are generally red and black, with the neutral white
and safety ground bare or green

On Sat, 23 Nov 2013 16:09:26 -0500, someone
wrote:

So it's 2-phase?

From what I learned, it's called SINGLE PHASE! 120-0-120 [240 total].

From Professor Cardell's web page at

http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

"There are two wires running out of the transformer and three wires running to the house.
The two from the transformer are insulated, and the third one is bare. The bare wire is the ground wire.
The two insulated wires each carry 120 volts, but they are 180 degrees out of phase so the difference between them is 240 volts."

On Mon, 25 Nov 2013 20:43:01 +0100, nestork wrote:

And what about this "ground," as mentioned above? The power company
essentially uses the earth as one of the wires in the power system. The
earth is a pretty good conductor and it is huge, so it makes a good
return path for electrons.

I'm glad you found that, because there MUST be a complete circuit for
current to flow (assuming an imbalance, as someone else noted).

The fact that the earth isn't obviously a "wire" is lost on some
people who simply assume earth is ground potential and that's that.

But, that's OK.

That's because *both* ways of thinking work just fine, simply because the
earth contains more electrons than anything on earth (which goes without
saying). It's like the car frame example. Exactly. Only on a huge scale.

So, both concepts work simply because earth and the car frame are special
things that don't look like wires, but, they act both like zero potential
and like wires.

Specifically, the earth is both a zero potential, and a huge conductor
back to the power company.

As Gallileo supposedly said on his deathbed to those who couldn't
fathom the wonders of the earth ... "and yet, it does".

On Mon, 25 Nov 2013 21:21:04 +1100, John G wrote:

You just do not understand.
AGAIN I tell you the ground has no part in the supply of power it all
happens on the wires and the ground is just the background.
Please got to school and learn the basic principles. :-?

Heh heh ... Let's just agree to disagree.

I understand your argument, and you understand mine.

I'm saying the earth can be thought of correctly either as zero potential,
or, as an absolutely humongous conductor back to the power company.

Both explanations work just fine:
- For you, you prefer to think of the earth as absolute zero potential.
- For me, I prefer to think of the earth as the return path to the power supply.

Both are perfectly valid, so, my only objection is you telling me
that I don't understand.

I'd be perfectly happy to be wrong, but, I think I *do* understand your point
(and I agree with you); but I think you don't agree with me. So, we'll never
get anywhere under those circumstances.

So, let's just agree that I think you're right and I think I'm right,
and that you think you're right and that I'm wrong. That's OK.

BTW, a thought-provoking question would be:
Q: Where do you think the power company gets its electrons from anyway?

On Mon, 25 Nov 2013 06:38:36 -0800, TimR wrote:

electrons don't actually get pulled from ground and sent to your house,
unless you have a DC supply. In AC, electrons merely bounce back and
forth a short distance, like a millionth of a meter.
The wave travels, but not the electrons. IIRC.

This is a good thought-provoking point.

The electrons do get bounced back and forth, but, isn't there "current"
in so much that *work* is being done, which requires the electrons to
actually "move"?

wrote in message
...

First of all, in North America, the typical p[ower supply is NOT 2
phase. It is center tapped single phase. You have a line1, a line2 and
a neutral - the neutral being shared between the two lines. If the
load is ballanced between the 2 "sides" there is no current in the
neutral. The neutral is regerenced to ground for safety reasons.

In early reural electrification in the USA, single wire distribution
was used - using "earth return" It worked, but was fraught with
problems, and is virtually unheard of today..


You might as well forget trying to explain that in most of the US the power
comes in to the house as a split single phase. Also that unlike a car and
much of the electronics where the frame/ground is often part of the circuit,
the AC power does not use the ground for anything but safety and not one
return leg. There are a couple on here that will never get it.

On Mon, 25 Nov 2013 05:15:29 -0800, wrote:

Which one you call A and which B is arbitrary. What matters
is that you wind up with the phases alternating on the breaker
slots, vertically. That way with a double pole breaker, you
get 240V. If they didn't alternate, you'd get 0v.

I'm ok with that.

It was interesting to see the "C" shaped flat metal plates
under each of the breakers in my panel.

That shows that my panel is a row of AA, then a row of BB,
then a row of AA, and BB, etc.

Thanks to you guys, I can *look* at a panel and tell something
about it now. That feels good.

(I hate not knowing stuff.)

On Monday, November 25, 2013 2:43:01 PM UTC-5, nestork wrote:
bud--;3155057 Wrote:



The earth does not complete the circuit. Wires complete the circuit.





Bud, until recently I would have agreed with you. But, whomever wrote

this web page obviously knows something about electric power generation

and distribution and seems to disagree:



http://tinyurl.com/y4syno6



Look at the bottom paragraph in the section entitled "The Power Plant:

Three Phase Power" where it says:





And what about this "ground," as mentioned above? The power company

essentially uses the earth as one of the wires in the power system. The

earth is a pretty good conductor and it is huge, so it makes a good

return path for electrons. (Car manufacturers do something similar; they

use the metal body of the car as one of the wires in the car's

electrical system and attach the negative pole of the battery to the

car's body.) "Ground" in the power distribution grid is literally "the

ground" that's all around you when you are walking outside. It is the

dirt, rocks, groundwater, etc., of the earth.





I don't think he could have said it any clearer.




And just before that, the author, said:

"There are four wires coming out of every power plant: the three phases plus a neutral or ground common to all three."

That sentence alone shows that he doesn't know what he's talking
about. A netural or ground wire are not the same thing. And even if they
were, if the earth were used as the return path, then why would you
need the 4th wire? The 4th wire carries the unbalanced current. The
current is flowing in the 3 phase wires and neutral, not the ground.

On Mon, 25 Nov 2013 15:10:28 -0500, clare wrote:

Line1 and Line2 are generally red and black, with the neutral white
and safety ground bare or green

Everything you said about the "single phase" center tap made perfect sense.

People keep saying the neutral wires is normally bare, but, I must
say, mine is insulated.
http://farm4.staticflickr.com/3780/1...9139da3c_o.gif

Maybe that's odd, for the USA though, 'cuz everyone is saying that
the neutral is normally bare.

On Mon, 25 Nov 2013 21:24:40 +1100, John G wrote:

Please go to school and learn the basic principles of electricity :-@

This is probably not called for.

I think my only mistake so far was "assuming" the lines coming into the
home were 120 degrees out of phase (because I understood distribution
but not the center-tapped transformer stuff). I now know they are
180 degrees out of sync with each other (because they come from the
center tapped transformer which is fed only one of the distribution
lines).

The only other place where you and I disagree is that you don't consider
the ground going back to the power company, whereas I do, and so do
some references - and yet - I also allow your characterization of the
ground being simply something that you can't change the potential of.

So, I think I don't need to go back to school so much as I simply disagree
with you on a relatively minor point, which is how the circuit is
completed.

On everything else, we agree, it seems, so, why do you incessantly
(three times so far) tell me to go back to school?

We all get along here because we treat each other with respect.

On Mon, 25 Nov 2013 09:29:02 -0500, Patty wrote:

IIRC, current carrying (line and neutral) conductors in a conduit must be insulated.

I don't disagree.

It seems to me that if the load is imbalanced on circuit A versus circuit B
(which is almost certainly likely to happen at some time or another), then
there *will* be current in the neutral. Period.

If there is current, and if there is resistance, there is a potential. Period.

So, it seems to me, it's a mighty good idea to insulate the neutral.
Clearly mine is well insulated.

It would be nice to see pictures from other typical homeowners in the USA
as to whether theirs is insulated or not.

On Monday, November 25, 2013 4:17:55 PM UTC-5, Danny D'Amico wrote:
On Mon, 25 Nov 2013 20:43:01 +0100, nestork wrote:



And what about this "ground," as mentioned above? The power company

essentially uses the earth as one of the wires in the power system. The

earth is a pretty good conductor and it is huge, so it makes a good

return path for electrons.



I'm glad you found that, because there MUST be a complete circuit for

current to flow (assuming an imbalance, as someone else noted).



As has been explained a dozen times now, there is a complete
circuit and under normal conditions, the earth is *not* part of
it. You continue to ignore the *neutral" and the fact that with
a balanced 3 phase load, the entire current flows in the 3 phase
conductors.






The fact that the earth isn't obviously a "wire" is lost on some

people who simply assume earth is ground potential and that's that.



But, that's OK.



That's because *both* ways of thinking work just fine, simply because the

earth contains more electrons than anything on earth (which goes without

saying). It's like the car frame example. Exactly. Only on a huge scale.


Nonsense. You and Nestork are claiming that the power company
delivers power using the earth as one of the conductor that
complete the circuit. That isn't an alternate way of thinking, it's
just wrong.



So, both concepts work simply because earth and the car frame are special

things that don't look like wires, but, they act both like zero potential

and like wires.



More obfuscation and confusion.




Specifically, the earth is both a zero potential, and a huge conductor

back to the power company.



Wrong.




As Gallileo supposedly said on his deathbed to those who couldn't

fathom the wonders of the earth ... "and yet, it does".

Gallileo didn't know much about electricity, did he?

On Monday, November 25, 2013 4:26:14 PM UTC-5, Ralph Mowery wrote:
wrote in message

...



First of all, in North America, the typical p[ower supply is NOT 2

phase. It is center tapped single phase. You have a line1, a line2 and

a neutral - the neutral being shared between the two lines. If the

load is ballanced between the 2 "sides" there is no current in the

neutral. The neutral is regerenced to ground for safety reasons.



In early reural electrification in the USA, single wire distribution

was used - using "earth return" It worked, but was fraught with

problems, and is virtually unheard of today..





You might as well forget trying to explain that in most of the US the power

comes in to the house as a split single phase.


I don't see anyone here denying that it's called "split-phase". The
transformer splits a single PRIMARY phase.
What generally happens when you split something? Do you still have
just one? What's at issue is that you have two legs that are
180 degrees out of phase with each other. That simple true statement
is where all the diagreement began. You can see two voltage waveforms
180 deg out of phase on a scope.
If they were not out of phase by 180 deg, you would not get 240V.
Here, from two electrical eqpt manufacturers that talk about two
phases, 180 deg out of phase:

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

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


And the IEEE clearly agrees that there are in fact two phases present.
From a paper presented at a recent IEEE power engineering conference:

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

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


Are IEEE power engineers and electrical eqpt manufacturers wrong?

I'm still waiting for someone on the other side of this to give
their definition of "phase" and why if one can see two phases on a
scope, there are not in fact two phases present.

On Monday, November 25, 2013 4:22:33 PM UTC-5, Danny D'Amico wrote:
On Mon, 25 Nov 2013 21:21:04 +1100, John G wrote:



You just do not understand.

AGAIN I tell you the ground has no part in the supply of power it all

happens on the wires and the ground is just the background.

Please got to school and learn the basic principles. :-?



Heh heh ... Let's just agree to disagree.



I understand your argument, and you understand mine.



There isn't an argument, John is right.



I'm saying the earth can be thought of correctly either as zero potential,

or, as an absolutely humongous conductor back to the power company.





The problem is the earth isn't used as a humongous conductor by the
power plant.




Both explanations work just fine:

- For you, you prefer to think of the earth as absolute zero potential.

It is zero potential relative to the grounded neutral. That
doesn't mean there is current flowing in the earth. To have something at
zero potential doesn't even require a circuit. Take a metal
cabinet sitting on an insulator and hook a wire from it to another
metal object, or a neutral, a 120V hot wire, a 7KV primary. They are
now at the same potential and no current is flowing.




- For me, I prefer to think of the earth as the return path to the power supply.



Both are perfectly valid, so, my only objection is you telling me

that I don't understand.



They are *not* both valid. You have it wrong.




I'd be perfectly happy to be wrong, but, I think I *do* understand your point

(and I agree with you); but I think you don't agree with me. So, we'll never

get anywhere under those circumstances.



Sigh....



So, let's just agree that I think you're right and I think I'm right,

and that you think you're right and that I'm wrong. That's OK.



On this point John is correct, and you still have it wrong.

On Monday, November 25, 2013 3:10:28 PM UTC-5, wrote:
On Mon, 25 Nov 2013 08:21:10 +0000 (UTC), Danny D'Amico

wrote:



On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:



From Professor Cardell's web page at



http://www.science.smith.edu/~jcarde...ecPwr_HSW.html



"There are two wires running out of the transformer and three wires running to the house.

The two from the transformer are insulated, and the third one is bare. The bare wire is the ground wire.

The two insulated wires each carry 120 volts, but they are 180 degrees out of phase so the difference between them is 240 volts."



Why are all three of mine insulated?

http://farm3.staticflickr.com/2886/1...21cf1404_o.gif





First of all, in North America, the typical p[ower supply is NOT 2

phase. It is center tapped single phase. You have a line1, a line2 and

a neutral - the neutral being shared between the two lines. If the

load is ballanced between the 2 "sides" there is no current in the

neutral. The neutral is regerenced to ground for safety reasons.



In early reural electrification in the USA, single wire distribution

was used - using "earth return" It worked, but was fraught with

problems, and is virtually unheard of today..



Today's power distribution is 3 phase - with each phase feeding a

separate distribution transformer - which has a center tapped

secondary for residential power. 3 phase is supplied for industry and

some multi-unit residential buildings which run 120/208 instead of

120/240. This is because 3 phase power is 120 degrees phase to phase.

because the generating system IS 3 phase, there can not be 2 "phases"

180 degrees apart.



Tell that to my lying scope. You put the two hot legs of the
split-phase service on a scope and what do you see? Two
phases that differ by 180 degrees. If they didn't differ by
180 degrees, you would not have 240V. It's every bit as real as
seeing 3 phases on a scope that are 120 deg seperate.

White papers/app notes from two electrical eqpt manufacturers:

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

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

IEEE peer reviewed paper delivered at a recent power engineering conference:

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

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

On 11/25/2013 04:39 PM, Danny D'Amico wrote:
It would be nice to see pictures from other typical homeowners in the USA
as to whether theirs is insulated or not.

The only time I've ever seen a bare neutral is in a service entrance cable between the meter and the breaker panel.

And while in most areas it meets code to use service entrance cable, I would only use conduit.

After serious thinking Danny D'Amico wrote :
On Mon, 25 Nov 2013 09:29:02 -0500, Patty wrote:

IIRC, current carrying (line and neutral) conductors in a conduit must be
insulated.

I don't disagree.

It seems to me that if the load is imbalanced on circuit A versus circuit B
(which is almost certainly likely to happen at some time or another), then
there *will* be current in the neutral. Period.

If there is current, and if there is resistance, there is a potential.
Period.

So, it seems to me, it's a mighty good idea to insulate the neutral.
Clearly mine is well insulated.

It would be nice to see pictures from other typical homeowners in the USA
as to whether theirs is insulated or not.

I don't believe anyone has said the neutral is not insulated.

ONLY the ground can be Uninsulated or GREEN or GREEN and YELLOW
The Neutral is generally white and the 2 actives are black or red.

--
John G

On 11/25/2013 05:25 PM, wrote:
Tell that to my lying scope. You put the two hot legs of the
split-phase service on a scope and what do you see?

How many phases does your oscilloscope show when you put the probe *reference clip* on L1 and the probe *tip* on L2?
(Mine shows a single-phase sin wave)

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

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



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

On Monday, November 25, 2013 5:53:24 PM UTC-5, John G wrote:
After serious thinking Danny D'Amico wrote :

On Mon, 25 Nov 2013 09:29:02 -0500, Patty wrote:



IIRC, current carrying (line and neutral) conductors in a conduit must be

insulated.



I don't disagree.



It seems to me that if the load is imbalanced on circuit A versus circuit B

(which is almost certainly likely to happen at some time or another), then

there *will* be current in the neutral. Period.



If there is current, and if there is resistance, there is a potential.

Period.



So, it seems to me, it's a mighty good idea to insulate the neutral.

Clearly mine is well insulated.



It would be nice to see pictures from other typical homeowners in the USA

as to whether theirs is insulated or not.



I don't believe anyone has said the neutral is not insulated.



ONLY the ground can be Uninsulated or GREEN or GREEN and YELLOW

The Neutral is generally white and the 2 actives are black or red.



--

John G

The typical and very common overhead service coming into a house
is an example of an unisulated neutral, isn't it? All the wire
manufacturers sell service cable with an uninsulated neutral, so
somone must be using it.....

On Mon, 25 Nov 2013 14:15:05 -0800, wrote:

They are *not* both valid. You have it wrong.

Well, this entire discussion is about how the power supply works, so,
it is germane to the discussion how the power company completes the
circuit.

I don't have any more arguments, and, we *do* have at least one
reference which supports my statement.

That doesn't mean I'm correct. What it means is we need more references
(either way), instead of our statements (since we all sincerely believe
what we're stating).

Googling for:
"how does electricity get back to the power company -solar"

This is on the first page (which was referenced already):
http://science.howstuffworks.com/env...rgy/power3.htm
It agrees with what I said (on page 4).

Here it says the same thing (that the earth is the return path):
http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

And he
http://www.electricityforum.com/elec...-it-works.html

But those are all repeats. How about this Physics forum?
http://www.physicsforums.com/showthread.php?t=429670

Now, that does not prove that the earth is the return path
for the electricity back to the power company, but, it is clearly
a half dozen (or so) references which say what I've always thought
was the case.

That means that the idea isn't so far fetched as it may appear.
Admittedly, most of these references were cut out of the same
mold (probably due to my search terms?), so I welcome someone
who can find a reference that says the earth is *not* the return
path for the HVAC typical power generated in the USA.

On Mon, 25 Nov 2013 13:43:23 -0800, wrote:


As has been explained a dozen times now, there is a complete
circuit and under normal conditions, the earth is *not* part of
it. You continue to ignore the *neutral" and the fact that with
a balanced 3 phase load, the entire current flows in the 3 phase
conductors.

Let's stop arguing *our* viewpoints and come up with references.
I found a half dozen references which said the ground is the
return path to the power company, including one physics forum.

Let's now try to find a reference that refutes that.

Specifically, let's find a reference that says the ground is
*not* the return path to the power company.

Note: It will likely be easy to find references that don't
state either, so, the important point is to find a reference
that specifically says the ground is *not* the return path.

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

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

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



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

(Mine shows a single-phase sin wave)



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





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



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







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

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

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

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

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

On Mon, 25 Nov 2013 13:43:23 -0800, wrote:

That isn't an alternate way of thinking, it's
just wrong.

Again, I don't think we'll get anywhere with you saying it's wrong,
and me saying they're both right. We can repeat ourselves until we're
blue in the face, and we'll get nowhere toward the correct answer.

We clearly showed multiple references, some of them from schools and
physics forums, which clearly stated the ground is the return path
back to the power company. This may or may not be true, but, we
can certainly find people stating that this is the case.

But, maybe all those web sites & physics forums are wrong.

If we are to learn the truth, what we need is simply a reliable
reference that says the ground is *not* the return path.

Clearly LOTS of people think it is (I certainly do, and so do the
half dozen scientific, howto, and physics web sites I referenced).

So, if they're all wrong (and they just might be), then there should
be a reference that says that this is wrong. Right?

So, if it is really "nonsense" that the ground is the return path
to the power company, then we should be able to find a reference
that says that.

Don't you think?
I googled, but didn't find it.

Maybe someone else can? (I'm not wedded to an opinion; I only wish for
the truth).

On Mon, 25 Nov 2013 14:25:59 -0800, wrote:

Tell that to my lying scope. You put the two hot legs of the
split-phase service on a scope and what do you see? Two phases that
differ by 180 degrees. If they didn't differ by 180 degrees, you would
not have 240V. It's every bit as real as seeing 3 phases on a scope
that are 120 deg seperate.

These are typical of the breakers in my panel.

http://www.amazon.com/Siemens-Q220-2.../dp/B00002N5HI

My panel was installed by a licensed master electrician.
The panel passed inspection.

The breakers are not listed for 2 phase service, only single or 3 phase.

Who should I sue for installing a panel not listed for 2 phase service?
The electrician? Electrical inspector? Siemens?

And last but not least, where do I find 2 phase breakers?

On Mon, 25 Nov 2013 16:26:14 -0500, Ralph Mowery wrote:

the AC power does not use the ground for anything but safety and
not one return leg.
There are a couple on here that will never get it.

If the statement is true, then you should be able to find at least
one reliable reference that supports your supposition. Right?

It's not like the question has never been asked before.

I provided more than a half dozen references which supported the
statement that the ground, in the typical USA AC transmission system,
is the return path to the electric company.

I admit, those references seemed to be from howto, school, and
physics web sites - but it was all that I could find.

However, I could not find a single reference that stated that the
ground is *not* the return path to the power company.

If it's true that the ground is not the return path, given that
clearly a LOT of sites say that it is, then why can't we find a
single reliable reference that explicitly refutes that assumption?

Again, I'm perfectly happy to be wrong if someone can prove they
are right. Merely stating that I'm wrong and that you are right
does nobody any good.

Let's see a single reliable reference that explicitly answers
the question by flatly refuting the (clearly common) assumption
that the ground *is* the return path back to the power company.

On Tue, 26 Nov 2013 09:53:24 +1100, John G wrote:

I don't believe anyone has said the neutral is not insulated.

I thought it was said here, but, maybe I misinterpreted the quote?

On Sat, 23 Nov 2013 16:09:26 -0500, someone wrote:
From Professor Cardell's web page at
http://www.science.smith.edu/~jcarde...ecPwr_HSW.html

"There are two wires running out of the transformer and three wires
running to the house.
The two from the transformer are insulated, and the third one is bare.
The bare wire is the ground wire.
The two insulated wires each carry 120 volts, but they are 180 degrees
out of phase so the difference between them is 240 volts."