How does the typical mains power connect in the USA anyway?

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

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".
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On Monday, November 25, 2013 4:17:55 PM UTC-5, Danny D'Amico 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.

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.

More obfuscation and confusion.

Wrong.

Gallileo didn't know much about electricity, did he?
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On Mon, 25 Nov 2013 13:43:23 -0800, snipped-for-privacy@optonline.net wrote:

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.
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On Mon, 25 Nov 2013 23:36:07 +0000 (UTC), Danny D'Amico

It is *NOT* a viewpoint. It is a fact.

They're wrong.

You already have.

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On Mon, 25 Nov 2013 23:36:07 +0000 (UTC), Danny D'Amico

Try http://en.wikipedia.org/wiki/Electric_power_distribution#Modern_distribution_systems
I know, it's only a WIKI, but in part it states: "A ground connection to local earth is normally provided for the customer's system as well as for the equipment owned by the utility. The purpose of connecting the customer's system to ground is to limit the voltage that may develop if high voltage conductors fall down onto lower-voltage conductors which are usually mounted lower to the ground, or if a failure occurs within a distribution transformer. If all conductive objects are bonded to the same earth grounding system, the risk of electric shock is minimized. However, multiple connections between the utility ground and customer ground can lead to stray voltage problems; customer piping, swimming pools or other equipment may develop objectionable voltages. These problems may be difficult to resolve since they often originate from places other than the customer's premises."
Only in some rather rare circumstances is the "ground" actually used in place of a current carrying conductor - eg. In New Zealand, Australia, Saskatchewan, Canada, and South Africa, single wire earth return systems SWER are used to electrify remote rural areas.Here they use galvanized iron wire in place of copper and run higher than normal voltages to compensate for the extra resistances involved. Obviously these are only single phase, single voltage distribution systems where a multi-tap transformer is used to adjust the end user voltage.
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On Mon, 25 Nov 2013 21:52:34 -0500, clare wrote:

This reference from Smith College, Northampton, MA: http://www.science.smith.edu/~jcardell/Courses/EGR220/ElecPwr_HSW.html
Says: "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."
That's from an EE class: http://www.science.smith.edu/~jcardell/Courses/EGR220/ EGR 220, Spring 2013, Engineering Circuit Theory
Taught by Judith Cardell, who researches this stuff: http://www.science.smith.edu/~jcardell/
She should know, shouldn't she?
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On Tue, 26 Nov 2013 05:07:43 +0000 (UTC), Danny D'Amico

She is referring to the "safety groun d", not the neutral, or she is "dumming it down". It IS still used as a ground return on a VERY small basis in very limitted locations - as SWERT.
She SHOULD know, but obviously is not expressing her knowledge very well.
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On Tue, 26 Nov 2013 08:16:40 -0500, clare wrote:

heh heh ... rather than supply a reference, another guy also attacked the credentials of the many references providing, implying, essentially, that facts taught at a junior college are essentially wrong, simply because it's not a four-year college.
And, now you bring up SWERT, which also has nothing to do with the question of typical power distribution in the United States, since neither you nor I are getting our household power through SWERT.
Let's keep SWERT out of this because the entire discussion is about the typical US power distribution system, which is basically how we're getting the electrons to do this typing at our keyboards.
Also, let's not try to prove our points simply by stating that the reference is wrong because it's from a junior college or that the answer is simplified so therefore it must be wrong.
The statement the professor made is simplified, but, it's not untrue because it's simplified.
The class teaches students: "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."
Anyway, I'll stop asking for a reference that shows otherwise.
What I'll do is continue to try to understand the typical power distribution scheme in the United States, with your help.
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On Tuesday, November 26, 2013 9:20:18 AM UTC-5, Danny D'Amico wrote:

Claire provided you with reference that talk about grounding power systems. They don't talk about the earth being used as part of the power flow path.
And again, ALL your references are straight back to the one "How stuff works", which has it wrong. Citing the same thing 10 times doesn't make it right.

Good grief. It directly addresses the issue. They talk about using the earth as a return path in special cases, eg isolated rural areas in AU. And they give a list of problems with it, why it's the exceptional case.

Fine, so then we're back to you being wrong.

Where is the link to what the prof actually said? Or is it like I think it is, that she's just using a link to "How stuff works?"

Look at the Wikipedia animation.
http://en.wikipedia.org/wiki/Three-phase_electric_power
Case closed.
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On Tue, 26 Nov 2013 07:09:18 -0800, snipped-for-privacy@optonline.net wrote:

Ok. You win.
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on 27/11/2013, Danny D'Amico supposed :

You will never understand while you insist on quoting generalised rubbish. The neutral is often grounded for safety reasons but except SWER systems (rare as they are) the mud is NOT used to carry any real part of the circuit. :-? In case you did not realise proof of NEGATIVES is very often hard to find in any field of endevour. :-?
As I said way back in the beginning of this long thread-- GO to a real College and learn the principles of Electricity :-?
--
John G



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On Wed, 27 Nov 2013 11:01:51 +1100, John G wrote:

??

OK. You win.
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On Tue, 26 Nov 2013 19:11:54 -0500, Ralph Mowery wrote:

Hi Ralph,
If a LOT of people think that you get a cold from being cold, then you can rest assured that an MD would explain that you get colds from viruses.
If a some people think that AIDS can be transmitted by a sneeze, then you can rest assured that another MD will explain that it's not transmitted that way.
If a group of people think that high octane gas is more "powerful" than lower-octane rated fuels, then you can rest assured that the Gasoline FAQ will explain what an octane rating really means.
If some lesser educated people confuse who versus whom, or lay versus lie, then you can rest assured that there will be linguists who explain the difference, in detail, on the web.
Point is, there are *many* examples of negatives being explained.
Anyway, I'm sick and tired of that part of this discussion, simply because people are wedded to their views and all they can do is attack the references, without supplying a single reference to the contrary (yes, I read the entire 10-page paper on grounding systems, and it didn't cover that specific point at all, at least not in plain language that *I* could understand).
Anyway, I learned a lot in this thread, and I, for one, am grateful for the conversation with my friends and compatriots on a.h.r, from whom I have the greatest respect.
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On Tuesday, November 26, 2013 8:16:40 AM UTC-5, snipped-for-privacy@snyder.on.ca wrote:

Who is the "she" here? Unless I'm missing something, what I think Danny showed us is the college having a copy of the same flawed explanation that Danny has posted from 6 other places. It all appears to me to have originated from the website "How stuff works", where that piece has Marshal Brain as the author.
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On Tuesday, November 26, 2013 12:07:43 AM UTC-5, Danny D'Amico wrote:

Good grief. Now I get it. A college course has a link to that same one reference "How stuff works", and that makes it right? Every single "reference" you keep coming up with, points right back to there. It's quite possible the associate professor didn't even fully read the thing. And you have to wonder about any college course that uses "How stuff works"
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On 11/25/2013 11:07 PM, Danny D'Amico wrote:

It is fatally flawed, as described in another post.

It is not from an EE class.
It is something Smith College picked up from somewhere. As far is I know it was not written by anyone ever associated with the college.

What should she know? She didn't write the piece at the top.
Why does everyone who understands power distribution disagree with you?
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On Tuesday, November 26, 2013 11:04:53 AM UTC-5, bud-- wrote:

Bud-
The one and only place AFAIK that all of this is coming from is the website "How stuff works". That link at the top produces the piece apparently authored by Marshal Brain. As I understand it, he's the creator of the "How stuff works" website. ALL the references Danny has are either the exact verbage from there repeated, a link back to it, or a copy thereof. You would hope that an assistant prof would check the stuff, but who knows if she did, who actually posted it as part of the course, etc. You also have to wonder about any college that uses stuff from "How stuff works" for course material.
But there is no question it's wrong.
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On 11/26/2013 11:46 AM, snipped-for-privacy@optonline.net wrote:

I didn't read Danny's other sources. I am really tired of his arguments. Interesting they are all the same thing.
I did see that Brain started "How things work" (I have seen other nonsense at that site).
Brain is presumably an EE. When I graduated there had been no reference to the NEC, and no practical information about power systems, and in particular earthing. Brain certainly shows no comprehension. krw, I think, said most EE course work is electronics. There are at least 3 other EEs here. I haven't noticed any have particular information on power distribution that they got in school.

I have not figured out how "she" has anything to do with the "piece" except "she" is a prof at the same college that put up the "piece".

But Danny found it on the internet....
Hey, didja hear that O J Simpson was framed by Romulans that beamed down from a cloaked war-bird and tampered with the evidence in the crime lab. If you don't believe it show me someone who says it isn't true.
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I don't know why NEC would be covered in any engineering coursework. It has no relevance.
Yes, I'm closer to microwatts than megawatts. My entire family are power engineers, though. I got a lot of it by osmosis, which is as close as I ever wanted to get to that stuff. ;-)

That's the way I see it. I believe she's been slandered.

Bon Jur!

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On Tuesday, November 26, 2013 5:34:45 PM UTC-5, bud-- wrote:

Well that'a a good point too. You're right. I was giving Danny the benefit of the doubt that the piece he keeps referencing from "How stuff works", was included as part of the course at Smith College. But you're right, from the link provided, it just shows that it's hosted at the college. Not sure by who or for what purpose. It's also worth noting that Smith is pretty much a liberal arts college, not an engineering power house.
It looks like a lot of people have glommed on to that piece. Probably because it readily comes up when you do a search for that kind of thing, it appears to be a nice short tutorial on the subject. But as you say, it's seriously flawed. The sad thing is that Danny seemed to finally get the idea of the difference between netural and ground in a residential service.
You and I have pointed out inconsistencies in that piece, eg, interchanging usage of ground and neutral, saying that power is transmitted via 3 phase and a 4th neutral/ground and then saying power relies on the earth for return. You would hope that he could start to think in terms of what he learned about neutral and ground in a 240/120V service and start to question that piece himself.
A good question he should ask himself is, if using the earth is how it's done for power transmission, then why isn't it also done for that 240/120V service? Why use a neutral at all? The transformer and house are both connected via earth, so just get rid of all the neutrals. Think of the cost savings...... So, why do we have a neutral in the 240/120V service?
Note: For the less informend, I'm only suggesting he think about that as a rhetorical question.

LOL.
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