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.
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.....
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):
Here it says the same thing (that the earth is the return path):
And here:
But those are all repeats. How about this Physics forum?
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.
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.
ence clip* on L1 and the probe *tip* on L2?
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.
on L1 and the probe *tip* on L2?
the probe *tip* on L2?
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.
"Which now brings into focus the reality that standard 120/240 secondary sy stems are not single phase line to ground systems, instead they are three w ire 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 s econdary phases are separated by 180 degrees instead of three phases separa ted by 120 degrees. "
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).
These are typical of the breakers in my panel.
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?
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.
I thought it was said here, but, maybe I mis> From Professor Cardell's web page at
Ah, so AC power doesn't work? It's good to find that out after 40 years as an electrical engineer. ;-)
The work is being done by the "wave". They do move, just not very far. They make up for being home bodies (though it's more than a few micrometers, IIRC) by their numbers. These numbers are fairy easy to calculate but not tonight. ;-)
I didn't see anyone here saying it wasn't germane, only that you're wrong.
So, now one reference to a light-weight, novice level tutorial on power distribution is the authoritative source? Why don't you look at all the other sources that say he's wrong? As I already pointed out, you can start with looking at what the author of that reference himself said immediately preceeding:
" "There are four wires coming out of every power plant: the three phases plus a neutral or ground common to all three."
If the power company is using the earth, why would there be a 4th wire? And clearly the author doesn't understand the difference between a neutral, which is a current carrying conductor, and a ground. Neither did you until we explained it to you with regard to split-phase service to a house. But you don't have a clue to how it works on the primary side. I've told you at least 6 times now, that with a balanced load, which is what the world looks like to a power plant, there is no need for any return circuit path other than the 3 phase wires coming out. Good grief.
If you spent half the time looking that you do arguing, you'd have found plenty of references by now that say you're wrong. I'm starting to understand John's annoyance. You came in here not knowing a ground from a neutral. Now you're here acting like your opinion is worth as much as anyone else's. I believe John is an electrician. I'm an EE, Bud is too. All of us are telling you that you're wrong.
Good grief, that's a repeat of the same thing too. Right at the top it references "How stuff works". All those references use the exact same words, go back to the one same place, the same "How stuff works" guy.
Are you that stupid that you think 6 places that use the same incorrect source somehow makes it right?
Maybe you should do that yourself. You might learn something.
The return or the power company is the other phases.
But that's not how it works. The Earth is *not* part of the circuit. It's just used a reference point.
Irrelevant. Electrical power would work the same way if the Earth had no free electrons.
Nope. Not the same at all.
Wrong. It is just defined to be zero and everything is referenced to it.
...and here I thought it was Tesla who designed our power system.
It is *NOT* a viewpoint. It is a fact.
They're wrong.
You already have.
Why would the heating, ventilation and air conditioning go back to the power generating station ?
Now it's a clearly common assumption? Prior to you bringing it up, I never heard it before.
Here's a diagram for you:
Go part way down to the animated drawing that shows a 3 phase power plant connected to it's 3 phase load. Note the 3 wires and that planet earth is *not* part of the circuit.
That is how power is generated and delivered. They may use the earth somewhere in the world as part of some power delivery circuit for something, but if they do, it's the exception, not the typical 99% part of how power is delivered.
I never said I would call the service 2 phase. It's not referred to as that in the industry. There is no disagreement that what comes into the panel originates from one phase of the electrical distribution system. It's like white tissues being called Kleenex. That doesn't change the fact that they are white, soft, tissues, does it?
I'm still waiting for someone on the other side of this to give your definition of the term phase. In electrical engineering, the most basic usage is the relationship between two periodic waveforms, expressed in degrees. If I see two waveforms that are different in phase, be it 120 deg, 90 deg or 180 deg, then there are two phases present and it can be viewed that way.
And what do you say to the fact that you have a very credible, experienced power engineer delivering a paper before the IEEE conf of power engineers that agrees that you have two phases present?
The utility service drop from the pole to the house typically has the neutral conductor uninsulated. From that point forward to the meter and the house distribution panel the neutral is insulated. In the house the ground conductors are typically not insulated, and the ground and neutral are bonded together only at the distribution panel. The neutral is a current carrying conductor that is ground*ed*, but being current carrying it may not be at ground potential at all points. The ground is a ground*ing* conduction that carries no current except under fault conditions. The service drop to the house does not contain a ground conductor, only the neutral and two hot conductors.
There is or was something called SWER, single wire earth return. A bit here:
SWER evidently isn't efficient according to this bit.
Quote:
Conductor characteristics. Line length varies according to customer distribution, with an average SWER feeder length of 60 km (37 miles), although a 400-km (250-mile) SWER system is in operation in one state. Therefore, circuit losses because of the high resistance of the SWER conductors, reactive losses in the isolating transformers and resistive losses in the earthing systems can be up to 100% greater compared to those of a single-phase (two-wire) system serving similar loads.
End quote.
OMG! So many spin-offs from something that has clearly been explained, time and again. So, instead of trying to answer each in turn, one reply to all that my frustrated head can remember.
In direct answer to your point, yes. The messenger wire is bare. Only between transformer and weatherhood. Once it goes into a conduit, it must be insulated. In fact, all wires in a conduit must be insulated. Bare wires in a conduit have a tendency to mess up the insulation of the insulated wires. In panels and J-boxes ground wires are allowed to be bare, but it is preferential to have them insulated, as well. Sort of the prevent surprises when jostling things about while performing a task in live boxes and such. Just for the record, I do not like metal cut-in boxes or nail-on boxes for switches or receptacles. Especially when solid wire is used (most romex). I pretty much cannot stand solid wire for most anything, unless it is in an application where the memory of said wire is desirable.
Another, quick point: Separate utility wiring from building wiring. The two are separate entities that follow different rules. Before the meter falls under the P.U.C. After the meter falls under N.E.C. With some exceptions for before the meter. Underground services that go to a common junction box may be considered part of the residence in some areas. I know this is true in Menlo Park, Ca. The utility considers the junction box in the sidewalk the end of utility responsibility. For the most part, all overhead to the weatherhood is utility, after the splice, is part of the residence. So, the splice point seems to be the utility cut-off.
Now, for the more general and completely fubar'd part.
Repeat after me, "The ground is not, never will be, never has been, nor ever will be a part of an electrical circuit." Not utility, not residence. The ground is not a good conductor. In fact, the ground is not homogenous, and in some locales is exceptionally horrid at conducting electricity at lengths of only a couple of meters. Most areas have already had a GEO done on them, and the local powers that be are aware of this fact and will require a ground resistance check to verify the viability of a ground electrode to facilitate an Earth bond. This is in no way a circuit connection. It is a potential energy connection. Part of the reason why multiple ground rods are required, now. Sometimes a bare cable must be installed, in a trench, to an engineered distance from the service entrance, or, even, all the way back to the utility ground location if the soil is that bad.
An individual may remove the ground connections at the meter-main, and at the transformer and the circuit will operate just fine. The ground wire does not aid nor hinder the electrical circuits. They are for safety, only. Well, some shady computer-power-supply manufacturers/mobo developers tried to go around this at one point in time. They don't do that anymore. :-) In fact, there was a time when one could not find a ground wire in a residence. The ground on the transformer was for when the overheads got knocked down from the weatherhood, for whatever reason, and the ground allowed a fault path back to the transformer so that the fuse on it would blow.
Now, some places are still stupid and might do things differently, so do not play the exception is the norm crap with me, please. Hell, go down to Australia, or some places in Canada, and scratch your head. Hell, there are places in the States that are that way, and power distribution in the States is not universal in all areas. Most areas will follow the rules of whom controls power transmission. Sometimes they don't get along with the others and will only agree on how the high tension lines are connected between different sources. After that, it's a local thing.
For instance. Here in Arkansas, at least in my region, there is one hot wire, and one neutral wire going to the primary of a residential transformer. Where I grew up in California, there were two hots and a neutral. Though, that is not necessarily how the whole state operated. Where I grew up was a long way to the nearest sub-station, and those familiar with poly-phase systems know that the current on poly-phase systems is substantially lower than single phase feeds. Just for those who might question: No, the feed was not two-phase, just two legs from a three-phase. The main trunk had four wires, three high, one low, on the pole with cable/phone even lower.
Danny, it is easy for a short or power malfunction to blow up more than one thing. Part of the reason I was wondering if there was a temperary open neutral condition. Regardless, I would junk your entire alarm system and install a new system. Check out Ebay. Screw the middle man. As an extra protection, buy a small U.P.S. and power the new system with that. Unless you have a contract with someone, your system doesn't do squat, anyway. So, why bother? If to only have an audible alarm, a much cheaper system may be obtained. Once again, check Ebay.
That's it, for now. Other things to do...
Well thank God we finally agree it is single phase service.
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