Just to confuse things even more... Since there is a ground connection on each end of the "Neutral" aerial wire there should be no current whatsoever on it. Max is correct as to it being carried on the neutral wires inside the house wiring from the receptacle back to the panel.

 

...and from the panel back to the transformer C.T., again this C.T. neutral conductor current will be the current Difference between L1/L2.
Max.

 

It all depends on where you live and the type of construction involved. For single home construction where there is sandy, clay, loam type soils ground rods are used. Obviously, you can't drive a 10' long ground rod into rock so that is where the metal water pipe connections are preferred. Then there are multistory apartment buildings and such which have other methods of grounding.

 

...and from the panel back to the transformer C.T., again this C.T. neutral conductor current will be the current Difference between L1/L2.
Max.

Okay, there is a bare solid wire under the floor by the foundation wall buried in the ground.

 

Because the Earth has a larger diameter than the wire maybe which gives it less resistance...

 

Because the Earth has a larger diameter than the wire maybe which gives it less resistance...

Here I opened a can of worms in the link below.

 

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.

You still have to connect like colors together. otherwise you get a short. Call them what you like.
HOT is blk and White - Neutral. Who knows where they came from except that back wire is easier to make? In larger current capacities where individual wires are run in conduit, they can be taped the colors that they are defined to be.

In fact, you should tape black, white wires that are HOT. If power is run to a ceiling light fixture and then a 2 conductor cable + ground run to the switch, the white gets colored black. https://www.reddit.com/r/electricia..._come_you_can_use_white_wire_with_black_tape/

That said, we have the problem of a reference.

In reality, wiring to a house was initailly non-polarized and had two pins the same size. I may have an example at home somewhere. So, it started out that way. Lighting was the major application for electric power in the home

What we have now is equally bad, but it's a compromise. Hospitals and transmitters will likely have two conductors connected to ground.

"Orange" outlets are used for "isolated grounded" outlets.

What is an "isolated ground"?

It means that the center pin of a 120 V receptacle connects to the Refererence and the box containing the receptacal can meander and get to that same place. So, a fault to the electrical box does not disturb the reference.

When you daisy chain outlets, the reference gets disturbed for every ground on that daisy chain. Computers that used ground as a reference could get into trouble. e.g. long cable and parallel printer in basement. Lightning strikes upstairs and poof. You also get ground loops.

Ethernet offers some protection against ground loops. It's isolated with a transformer.

We had metal appliances and the outer case was connected to ground. Thus any fault would blow a fuse. Now we have GFCI (Ground fault)
s and AFCI's. (Arc fault) circuit interrupters. The arc fault CI's try to listen" for a loose connection.

Your plumbing should also be connected to ground. Now we have isolated plumbing.

Your cable gets connected to a reference. The telephone and cable gets supression or one side is grounded because lightning strikes are highly probable.

Now the most important part, Ground, Earth and Neutral come together at only one point. This is the reference for the house. If there is a fault, that reference can change potential, but the house is not really affected except the daisy-chained outlets.

That reference is MAINTAINED with sub-panels. Neutral is isolated from ground in those panels and ground lugs are added.
Panels that are "detatched" from the service structure get their own ground rod too.

So, ideally, you should have hot, neutral, protective ground, and ground(reference), but we usually don't.

Now, here's a fun part, EARTH's potential changes too. It matters for sidewalks around swimming pools. They are bonded carefully, so the cement and the water are the same potential.

In a computing center where I worked, a storm took out a lot Ethernet going from one side to the other because the ground potential changed. They replaced that ethernet with fiber.

The power station is generating a high voltage, thus low current with respect to earth. When it gets to the transfomer it's single phase maybe 9.6 kV or so. P=VI= 200A*230=9600*I; So, 200A at the house is only 5A on the primary.

It's important to note that the neutral carries the DIFFERENCE current. You can have 200 A fully loaded on both sides of the split phase and have zero neutral current. Panels would not be fully loaded. Circuits are designed not to be fully loaded. Your looking at 80% of a "continuous" load. "continuous" has a special meaning. It's not 100% of the time.

There is a "sign" to that current, but it really doesn't matter.

The power company generates 3 phase power. A residence may get a piece of one of those phases.

 

The figure on the right, can you tell which one of the two-wire is the ground/neutral?

It's like reading a map, the standard convention is top of the map is north and top of the schematic is DC+ or AC Hot. Not that schematics always follow standard conventions. You have to learn to read the circuit and interpret it.

 

@KeepItSimpleStupid When we installed the PDP-11 running a DCS for a large distillation areas control room it had to have its own isolated ground system. What fun!

 

You still have to connect like colors together. otherwise you get a short. Call them what you like.
HOT is blk and White - Neutral. Who knows where they came from except that back wire is easier to make? In larger current capacities where individual wires are run in conduit, they can be taped the colors that they are defined to be.

I

 

...and from the panel back to the transformer C.T., again this C.T. neutral conductor current will be the current Difference between L1/L2.
Max.

 

Not too bad. The "flow of electrons" is a myth, but in this case it illustrates what he needed to do.
I don't like calling the negative terminal of battery Neutral, but it's an analogy here/

Earth is really a safety thing. It's also troublesome especially when "ground loops" are introduced. These "loops" can be responsible fro hum in an audio system for instance. It's hard to not have differences in ground potentials. the only way to not have them is to return all wires to one point. That isn't practical.

You can isolate the sources.
You can place similar common paths together.

Digital ground is dirty
A shield doesn't carry current
An analog reference
A high current ground, has various potential differences,

Now connect them to one spot. Everything behaves better.

In low-cost instrumentation, you might have a pseudo-differential input. This has two inputs that measure with respect to ground. It only works on a grounded source. You can read the reference of the output.

If you use a current source as an output (the setpoint of an instrument) then you can place a resistor across where the setpoint voltage goes.
So 20 mA across 250 ohms is 5V. Look, no ground loops.

I was modifying a home made 6 channel readout box for 6 mass flow controllers for computer control and I missed something. The MFC required a +- 15 v supply and that's not a problem. The normal non-computerised way of setting a value was use a potentiometer. The ground reference was the card itself. All good.

Add a 5v calibration signal and you have an Oops. Try to control the setpoint relative to each MFC and you have an Oops. The setpoint should have had a difference amplifier inserted. Oh well.

 

@Alchemy One

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I am assuming the system being AC, the current alternate between the ground and the and the other two wires, back and forth, back and forth. how can neutral be 0A, how does the 120V complete the circuit, back and forth? And why do the arrows point one way only, Where is the loop or more like the back and forth jiggling current? Yea I got lost again. I will somehow manage to live another day.

Earth in this circuit is not about moving electrical energy. The Earth connection is only for external factors like natures lightning or mans misadventures with the electrical wiring. The arrows show the instantaneous phase and current relationship of the circuit. The back and forth jiggling current in the circuit is like the chain and sprocket on a bike. It just moves round and round as a means to transfer energy between the petals and the wheels using tension (a archaic but still used term for voltage). If you jiggle the pedals while you hand is on the wheel you are still transferring power only in one direction. pedal -> wheel.

https://forum.allaboutcircuits.com/...nd-resistance-work.126746/page-2#post-1032641

 

I didn't want to bring it up but now the cat is out of the bag...

 

Okay, there is a bare solid wire under the floor by the foundation wall buried in the ground.
So why in the name of heavens current would follow that wire and go through dirt to complete the circuit and not through nice thick neutral bare wire up there that goes directly to CT?

The ground wire that is connected to earth is not intended to carry current but be a zero reference point and is used as a safety procedure, although the ground resistance requirement of 5ohms or less for the earth ground path resistance from installation back to the source ground point, will allow current to flow in the event of a equipment failure or fault etc.
For e.g. the GFI principle works on measuring the current in both 'live' conductor and the neutral, if there is any unbalance between the two, then it is assumed that current is also flowing from live through to ground and will result in a disconnection of the power.
Max.

 

I didn't want to bring it up but now the cat is out of the bag...

According to the animation, this is what I get.

 

Earth is a bad conductor.

Not necessarily so, it is relative.
As I mentioned, the return path should be measured in order to establish a return path of 5ohms or less, there is Utube videos by Bob Holt concerning ground measurements.
Max.

 

Not necessarily so, it is relative.
As I mentioned, the return path should be measured in order to establish a return path of 5ohms or less, there is Utube videos by Bob Holt concerning ground measurements.
Max.

Can you paste that Youtube link here possibly?
Thanks

 

Sorry it was Mike Holt videos. NOT Bob!

Max.