AC circuit big confusion after all these

Thread Starter

Alchemy One

Joined Oct 5, 2019
89
I am sorry to say this but I have yet to be convinced by any explanation I have read as to why on earth in real life house AC wiring system there is hot and ground wires.
 
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nsaspook

Joined Aug 27, 2009
6,220
It's not meaningless in the context of actual AC circuit potentials from point X in the circuit to a designated reference point (hot, neutral, ground or physical earth). The AC current in the wire is not the source of energy in the circuit. The current is part of a system that transports electrical energy from point A to point B in an efficient manner using fields. (More on that later if you want)

Can 'earth' be a circuit path for current? Yes, but it's rarely desirable under normal condition and it usually not the most efficient energy path from source to load because of higher electrical resistance than good electrical conductors..
 

Thread Starter

Alchemy One

Joined Oct 5, 2019
89
It's not meaningless in the context of actual AC circuit potentials from point X in the circuit to a designated reference point (hot, neutral, ground or physical earth). The AC current in the wire is not the source of energy in the circuit. The current is part of a system that transports electrical energy from point A to point B in an efficient manner using fields. (More on that later if you want)
 
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Externet

Joined Nov 29, 2005
1,403
Can you visualize an alternating current generator moved by say a hydroelectric dam with its two output wires pushing and pulling electrons ?

Can you visualize those two wires as a transformer primary input ?
upload_2019-10-5_21-9-36.png

Can you visualize a centre-tapped secondary of the transformer someone named it 'neutral' ?

Can you imagine the alternating pushing and pulling electrons happening at the terminals of Na secondary, no matter what connection may be done to them ?

Well, that transformer can be like the one hanging from the power pole near your house.
And its three secondary wires passing trough your power meter and then feeding your electric stove, wall outlets...
Between "+" and neutral you get 120VAC. Between "-" and neutral you get another 120VAC. Between "+" and "-" you get twice that, 240VAC

If someone decides to connect that 'neutral' wire to ground, nothing happens to the supply; just neutral gets connected to earth. Which also makes 120VAC also to ground, not just the neutral.

And be prepared to find maaaany things wrongly named from day one and taught like that.
 

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nsaspook

Joined Aug 27, 2009
6,220
Now, what happened to my ALTERNATING current? My problem with earth/dirt being used as a current-carrying conductor is a subject all by itself, ( the earth is sure no copper wire with free electrons. I don't want to talk about this. I guarantee it will change the subject). I want to see electrons jiggling back and forth to the load on the two wires equally as we are told what AC is.
Study this for a while: http://amasci.com/miscon/eleca.html#cflow

http://amasci.com/miscon/elect.html
 

crutschow

Joined Mar 14, 2008
23,152
I want to see electrons jiggling back and forth to the load on the two wires equally as we are told what AC is.
Since no-one has ever seen an electron I'm afraid you're out of luck for that. :rolleyes:
In household AC current there is hot and neutral (with neutral connected to earth ground).
All the means is the the AC voltage of the hot wire with respect to the neutral is going above and below ground potential.
The electrons are still equally "jiggling back and forth" in both the hot and neutral wires.
Don't get hung up on the words "hot", "neutral", or "ground" as they are just the name of voltage reference points.
They have absolutely no effect on the current in the wires.
Thus if you remove the neutral to ground connection, the current in the two wires will be unchanged.
Also note that there is normally no significant current flowing in the neutral-ground connection.
 

Externet

Joined Nov 29, 2005
1,403
The clarity the article yields is it is very clear we were taught with a collection of misnomers from people who did and still do not care about precision wording and proper concepts into students.
¿ When is it a power supply, or a voltage supply, an energy supply, a current supply ? :rolleyes:
Fully agree with the original post, and with the way too many things of this nature he will sadly find in the future. Someone comes up with senseless wording as 'boot up' ,'software' , and zillions follow without intervention/approval/consensus of a language 'police'.
Hot=live=phase=power= ... whatever they want to name.
 
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SamR

Joined Mar 19, 2019
1,060
We still haven't gotten over Benjamin Franklin's conventional flow of electrons and probably never will...
 

Thread Starter

Alchemy One

Joined Oct 5, 2019
89
I have no trouble following your diagram. It looks pretty clear. But the problem still remains.
 
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SamR

Joined Mar 19, 2019
1,060
earth is not really a path to real strong current
Ever heard of Lightning? Current doesn't get much stronger than that... I don't recommend this but if you stick your finger in the ground and grab a hot wire from your home power system with your other hand you would probably die before you came to the realization the earth is a pretty good conductor of electricity.
 

nsaspook

Joined Aug 27, 2009
6,220
I have no trouble following your diagram. It looks pretty clear. But the problem still remains. First of all one wire is hooked up to the dirt/earth. I am surprised that the Earth/dirt is a conductor like it is a copper wire that is for sure. To me, it would look like an open circuit. And if I sit here and tell myself to deal with it, the Earth is obviously a conductor wire. Now I am left with two more problems if not more. By definition it should becomes the current-carrying conductor halfway through each cycle, Alternates in that coil of the transformer, no? If not, it would mean it is not AC. If it does alternate we have a dangerous issue of the ground being a live wire.
And let's suppose that the ground is some sort of return and does not alternate at 60 Hz which would make no sense due to the reasoning of AC system. The problem is still there. it would be equivalent to walking on a current-carrying wire in all instances.
Furthermore, if we assume that earth is not really a path to real strong current, then we got major issue of high resistance.
Am I the only one that asks these questions and what is so not obvious that no one would ask what I have just brought up as a matter of immediate inquiry? My questions to me stick out like a sore thumb. And I have never seen anybody actually directly ask them instead of getting all lost in all kinds of technicalities and word bamboozlement, engineering jargon. :)
Birds walk on high voltage conductors carrying high currents all the time because there is low potential between their feet but people have died from ground potential rise that caused a lethal voltage between their feet during a lightning strike.

You need to stop just looking at current. It's the potential from point A to point B that matters into X resistance for power that matters in any instant during the 60 Hz cycle.

IMO you need to eventually see AC as a energy wave vector rotation in time and space instead of just a 2D projection of sine wave current. The engineering jargon is not something you can dismiss because until you understand it you won't really GROK electrical energy.

The actual direction of the electron or ions in the conductor don't matter as electrical energy flows between both wires (including the earth if it's a current carrying conductor) from the source to load.

All astute students eventually ask these question and good students study what's been posted to find the correct answers.
 

Externet

Joined Nov 29, 2005
1,403
... Now I am left with two more problems if not more...
Try something... Ignore, erase, delete the connection to earth from the transformer secondary centre tap on post #4.
It does not exist now. Your motor, heater, stereo, whatever is still connected to the points marked "+" and central tap.
Everything works the same. The planet under your shoes is not conducting anything. You can still visualize your push-pull on those terminals, right ?
 

WBahn

Joined Mar 31, 2012
24,576
These questions have all been asked and answered thousands of times. The problem is that you choose not to learn or understand the answers.

Are you familiar with the concept that the bigger the cross sectional area of a conductor the lower it's resistance? If so, then consider this:

Typical values of soil resistivity are 10 Ω·m to 1000 Ω·m. The resistivity for copper is about 2x10^-8 Ω·m. So, yes, the resistivity of soil is about 9 to 11 orders of magnitude greater than copper.

But now consider that a current flowing through the ground can spread out pretty much as wide and deep as needed, which a current flowing through a copper power line is constrained to the relatively small area of the wire.

What is the ratio of the cross sectional area of a 1 cm diameter copper wire to a ground current that is spread out over a cross sectional area having an effective diameter of, say, just 100 meters? Right there is eight orders of magnitude.

For some of your other questions, consider taking a very high voltage battery (say 1000 V -- they DO exist) and standing next to it and grabbing one (just one) of the terminals. What happens? Nothing. Now let go and grab the other terminal. What happens? Nothing. Now put the battery in a structure (building, car, boat, whatever) and flip a coin and connect one of the terminals to the frame of the structure and then use the other terminal to power lights and other things by connecting a wire from the other terminal to one side of the light and connecting the other side of the light to the frame. Can you touch the frame without getting electrocuted? Of course. Does it make any difference where you use a 1000 V DC battery or a 1000 V AC generator?
 
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