# Can someone explain



## Roger.

Sunny 1 said:


> Hey guys!!! I'm confused and hope someone can make light of this. I'm sitting here reading article 250 in my Mike Holt "Understanding The NEC" book, and stumble upon this:
> 
> "Danger: Because the resistance of the earth is so high, very little current returns to the electrical supply source via the earth. If a ground rod is used as the ground-fault current path, the circuit overcurrent protection device will not open and metal parts will remain energized."


 Dirt itself has very high resistance and using ohms law E/R = I figure out how much current will flow if your GES had a resistance of 25 ohms



Sunny 1 said:


> First, I thought the earth had little resistance? If not, then why are we grounding to begin with?


 Not small portions of earth and your question has been pondered by many but, it is basically for HV surges and Lightning strikes.



Sunny 1 said:


> Also, I know it's a violation to use the building's grounding system as a "Effective ground fault current path", but why wouldn't the breaker trip if this system was used as such?


Ok using the formula above for a 125 volt circuit 125 / 25 = 5 amps, that won't do much to trip a 15 or 20 amp breaker.

Roger


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## McClary’s Electrical

Sunny 1 said:


> Hey guys!!! I'm confused and hope someone can make light of this. I'm sitting here reading article 250 in my Mike Holt "Understanding The NEC" book, and stumble upon this:
> 
> "Danger: Because the resistance of the earth is so high, very little current returns to the electrical supply source via the earth. If a ground rod is used as the ground-fault current path, the circuit overcurrent protection device will not open and metal parts will remain energized."
> 
> First, I thought the earth had little resistance? If not, then why are we grounding to begin with?
> 
> Also, I know it's a violation to use the building's grounding system as a "Effective ground fault current path", but why wouldn't the breaker trip if this system was used as such?


 Ohms law . Simple math 20 ohms at 120 volts would never open an ocpd.


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## don_resqcapt19

The earth itself has a huge cross sectional area and the resistance of the earth itself approaches zero ohms. The problem is the connection between the grounding electrode and the earth. That is where the high resistance comes in. 

As far as why we are grounding the system, take a look at 250.4(A)(1).


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## Sunny 1

Roger. said:


> Dirt itself has very high resistance and using ohms law E/R = I figure out how much current will flow if your GES had a resistance of 25 ohms
> 
> Not small portions of earth and your question has been pondered by many but, it is basically for HV surges and Lightning strikes.
> 
> Ok using the formula above for a 125 volt circuit 125 / 25 = 5 amps, that won't do much to trip a 15 or 20 amp breaker.
> 
> Roger


Does the ground rods have resistance of 25 ohms each= 50 ohms together? Or is it 25 ohms between the 2 of them?


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## Roger.

Sunny 1 said:


> Does the ground rods have resistance of 25 ohms each= 50 ohms together? Or is it 25 ohms between the 2 of them?


25 is just a random number (and the required resistance if using one rod) you could have infinity (well, infinity on a scale) with more than one rod and be legal. 


Adding rods in theory is to lower resistance not increase it.


The point is, earthing at the voltages we as electricians deal with will do very little for equipment bonding puposes.


Roger


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## chicken steve

The usual confusion lies in how a GEC and EGC differ.

A GEC provides premisis sine wave stability & mitigates lightning strikes

An ECG deals with faults back to the OCPD's 

~CS~


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## Sunny 1

Roger. said:


> Dirt itself has very high resistance and using ohms law E/R = I figure out how much current will flow if your GES had a resistance of 25 ohms
> 
> Not small portions of earth and your question has been pondered by many but, it is basically for HV surges and Lightning strikes.
> 
> Ok using the formula above for a 125 volt circuit 125 / 25 = 5 amps, that won't do much to trip a 15 or 20 amp breaker.
> 
> Roger


Thank Roger! You have made things a lot clearer now. But with that being said, I have just one last question. Why is it that when a live/phase conductor comes in contact with a grounded neutral conductor, does the breaker then trip? Can you clarify this for me? I mean what's the difference?


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## wildleg

low impedance path to the source (the breaker)


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## 480sparky

Get a copy of _Soare's Book on Grounding and Bonding_.


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## Roger.

Sunny 1 said:


> Thank Roger! You have made things a lot clearer now. But with that being said, I have just one last question. Why is it that when a live/phase conductor comes in contact with a grounded neutral conductor, does the breaker then trip? Can you clarify this for me? I mean what's the difference?


The term "grounded conductor" is simply a description of the second side of an AC circuit in a grounded system, we call it a neutral which is not really accurate in most cases and in reality, this conductor does not even have to be grounded to complete the circuit. 

What happens when you touch the first side of the circuit to the second side of the circuit with an extremely low resistance you have very high current flow.

Roger


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## Sunny 1

Roger. said:


> The term "grounded conductor" is simply a description of the second side of an AC circuit in a grounded system, we call it a neutral which is not really accurate in most cases and in reality, this conductor does not even have to be grounded to complete the circuit.
> 
> What happens when you touch the first side of the circuit to the second side of the circuit with an extremely low resistance you have very high current flow.
> 
> Roger


Your loosing me roger. The definition I have of the grounded neutral conductor is the conductor connected to the bar that is intentionally connected to earth


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## Sunny 1

Roger. said:


> The term "grounded conductor" is simply a description of the second side of an AC circuit in a grounded system, we call it a neutral which is not really accurate in most cases and in reality, this conductor does not even have to be grounded to complete the circuit.
> 
> What happens when you touch the first side of the circuit to the second side of the circuit with an extremely low resistance you have very high current flow.
> 
> Roger


I feel like I'm running in circles now. I thought we established that the grounded neutral conductor had to be grounded to create the "Effective ground fault path"


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## macmikeman

chicken steve said:


> The usual confusion lies in how a GEC and EGC differ.
> 
> A GEC provides premisis sine wave stability & mitigates lightning strikes
> 
> An ECG deals with faults back to the OCPD's
> 
> ~CS~


Please provide some solid proof of the above statement in red. I see it in print all over , but short in the solid evidence department. I came here to learn, but I do manage to have a few opinions I realize. One of them is that there isn't a whole lot of proof of the above , more like speculations.


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## RePhase277

Sunny, a "grounded neutral" is simply a neutral that happens to be grounded. A hot wire that touches a neutral trips the breaker because there is a complete circuit for current to flow. Grounding one wire does nothing to change short circuits in the line. 

Look at the pic of the two batteries I drew. One is grounded, the other isn't. There is no difference as far as line shorts are concerned.


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## chicken steve

macmikeman said:


> Please provide some solid proof of the above statement in red. I see it in print all over , but short in the solid evidence department. I came here to learn, but I do manage to have a few opinions I realize. One of them is that there isn't a whole lot of proof of the above , more like speculations.


 
I have no proof Mac, i'm simply repeating what i've been taught

in fact, i've questioned the efficacy of GEC's install methods quite a lot 

~CS~


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## Roger.

Sunny 1 said:


> I feel like I'm running in circles now. I thought we established that the grounded neutral conductor had to be grounded to create the "Effective ground fault path"


Sunny, the "Grounded Conductor" is the Effective Fault Clearing Path in that it completes the circuit back to the source ahead of the service equiment. Grounding (earthing) has nothing to do with this function of the conductor, see InPhases drawings in post # 15













The reason this conductor is grounded is explained in 250.4 as Don pointed out. 











The reason for bonding is to clear faults by taking the current back to the source, this is acheived by the EGC carrying the fault back to the neutral at the service equipment. In the illustration below take note of the Equipment Grounding Conductor carrying the fault current back to the Neutral conductor at the meter.














Roger


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## chicken steve

worth a 1000 words Rog....

~CS~


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## macmikeman

Except I have witnessed enough of crispy critter interior wiring systems after lightning strikes nearby to dwellings that causes me to still question the whole theory presented in the drawing and "teachings" about how it "limits" the strain on the system wiring. From up here on planet macmikeman it looks more like it contributes to the impact on the interior wiring of buildings than it does to lessen it. As for part two- high voltage imposed from the utility- make em run a bonding wire back to their equipment instead of making our cows jittery...

P.S. I also have a bumper sticker that says question authority......


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## Dennis Alwon

Mac if there is a direct lightning hit then no grounding system will help, IMO. Lighting is incredibly strong and if it hits the gec can only do so much.

The gec will help with smaller surges from poco and lightning


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## chicken steve

the 780 guys make some strong arguments about how GEC's are installed

and we almost always see this pix with the charge _leaving_ the GEC into the earth, where in could easily be _entering_ via a municipal water main, or even from an earth strike

guess we need to poll mother nature?

~CS~


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## don_resqcapt19

Sunny 1 said:


> I feel like I'm running in circles now. I thought we established that the grounded neutral conductor had to be grounded to create the "Effective ground fault path"


 This is just another example of why the NEC needs to eliminate the term "Equipment Grounding Conductor". That term stronly implies that the earth or the connection to ground is important for clearing faults. It is not. The only thing that is important for clearing faults is a low impedance path back to the source. 
It is my opinion that if the term EGC was replaced with the term "Equipment Bonding Conductor", that the idea that the earth is important would quickly go away.


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## Sunny 1

don_resqcapt19 said:


> This is just another example of why the NEC needs to eliminate the term "Equipment Grounding Conductor". That term stronly implies that the earth or the connection to ground is important for clearing faults. It is not. The only thing that is important for clearing faults is a low impedance path back to the source.
> It is my opinion that if the term EGC was replaced with the term "Equipment Bonding Conductor", that the idea that the earth is important would quickly go away.


I understand what your saying, but even if the faulty current go's back to the source, its my understanding that it's still is going back to ground. Am I right?? I mean, correct me if I'm wrong. When faulty current is returned back to the source, doesn't it go to the xo terminal of the transformer? Isn't the xo terminal grounded? Take this pic for example....


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## RePhase277

X0 at the transformer is connected to ground, but the ground still plays no part in the circuit. Electricity flows only in closed circuits. A transformer and it's associated wiring is a closed loop. The ground wires at each end are like spurs off the loop.

Put the image of a battery in your mind, like I posted. Pretend the battery is a transformer.


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## Sunny 1

InPhase277 said:


> X0 at the transformer is connected to ground, but the ground still plays no part in the circuit. Electricity flows only in closed circuits. A transformer and it's associated wiring is a closed loop. The ground wires at each end are like spurs off the loop.
> 
> Put the image of a battery in your mind, like I posted. Pretend the battery is a transformer.


Please help me a little further to understand what you are trying to say here InPhase. Im trying to keep up. Are you trying to say that in order to complete a circuit, we "DONT" need a path to ground at all?


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## macmikeman

Dennis Alwon said:


> Mac if there is a direct lightning hit then no grounding system will help, IMO. Lighting is incredibly strong and if it hits the gec can only do so much.
> 
> The gec will help with smaller surges from poco and lightning



Please Dennis provide all the empirical data from your scientific studies to date that show this . We both know you would never just offer conjecture or repeat what you have heard or read elsewhere without having conducted such. 


I offer that the utilities save the expense of one conductor by relying on transmission thru the earth as a fault return path, and thats why all the "grounding" is really done, misunderstandings, theories, traditions, and "well its how I was show how" and "cause its in the code book" by the entire industry notwithstanding.


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## wildleg

I'm not trying to sound demeaning, but every question you ask is inherently ambiguous because the terminology, while new to you, is very specific.

I strongly suggest you buy something like, for example, Mike Holt's CD on grounding and bonding. It explains all the concepts you are confused with, in great detail, and with pictures. You need pictures, descriptions of the exact terminology, and examples to understand several of the concepts here. It's important stuff, too.


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## Sunny 1

wildleg said:


> I'm not trying to sound demeaning, but every question you ask is inherently ambiguous because the terminology, while new to you, is very specific.
> 
> I strongly suggest you buy something like, for example, Mike Holt's CD on grounding and bonding. It explains all the concepts you are confused with, in great detail, and with pictures. You need pictures, descriptions of the exact terminology, and examples to understand several of the concepts here. It's important stuff, too.


I have the understanding of the NEC by Mike Holt. I'm reading article 250 now. Apparently I need more than those pics because what I got from them, according to you guys, are wrong


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## macmikeman

So just curious, but how does the garment district figure into all this, been hit by lightning?????


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## wingz

Sunny 1 said:


> I have the understanding of the NEC by Mike Holt. I'm reading article 250 now. Apparently I need more than those pics because what I got from them, according to you guys, are wrong


Hey Sunny,

Sunny, carefully read what Roger, Don and Dennis are saying. These guys are big hitters at Mike Holt and know their stuff.

Derek


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## Sunny 1

wingz said:


> Hey Sunny,
> 
> Sunny, carefully read what Roger, Don and Dennis are saying. These guys are big hitters at Mike Holt and know their stuff.
> 
> Derek


Ok gotcha


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## RePhase277

Sunny 1 said:


> Please help me a little further to understand what you are trying to say here InPhase. Im trying to keep up. Are you trying to say that in order to complete a circuit, we "DONT" need a path to ground at all?


Right. A complete circuit can exist with no ground at all. Just like your car battery works without being connected to ground. The space station in orbit is not connected to ground, yet circuits function normally.

A circuit is a path from a source, through a load, and back to the source.


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## Pete m.

InPhase277 said:


> The *space station* in orbit is not connected to ground


I personally think it should be connected to a ground rod (just in case....)

Pete


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## wingz

Pete m. said:


> I personally think it should be connected to a ground rod (just in case....)
> 
> Pete


Ufer, dude.Ufer.. only way to fly.


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## wingz

Sunny,

Short version- we ground( connect to dirt/earth) electrical systems because the NEC says so. Why? Who knows-I gave up trying to figure it out and do not care anymore. As long as I do it when required and properly I am satisfied.

We bond (create a path to clear faults) make total sense. It saves lives, equipment and prevents fires. This concept is critical and should be understood completely. Bonding clears faults, not grounding.

A lot of the confusion lies in the fact we still use terms like Equipment Grounding Conductor and grounding receptacle, when in fact these are bonding issues.

Derek


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## don_resqcapt19

Sunny 1 said:


> Please help me a little further to understand what you are trying to say here InPhase. Im trying to keep up. Are you trying to say that in order to complete a circuit, we "DONT" need a path to ground at all?


 Correct. A path or connection to earth has nothing to do with the normal operation of the circuit and almost nothing to do with fault clearing. 

I say "almost" because current flows on *all* available paths, in inverse proportion to the impedance of the paths, and once you have a grounded system, there will almost always be a parallel path back to the source via the earth. 

This path will have an impedance of thousands of times more than that of the EGC but it will still have some current on it. Fault clearing is a function of time and current. The more current we can get to flow, the quicker the fault will be cleared. The parallel path via the earth will flow a small amount of current and will help the OverCurrent Protective Device to clear the fault. The decrease in trip time as a result of the current flowing in the earth will probably be so small that you can't even measure it.


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## chicken steve

don_resqcapt19 said:


> Correct. A path or connection to earth has nothing to do with the normal operation of the circuit and almost nothing to do with fault clearing.
> 
> I say "almost" because current flows on *all* available paths, in inverse proportion to the impedance of the paths, and once you have a grounded system, there will almost always be a parallel path back to the source via the earth.
> 
> This path will have an impedance of thousands of times more than that of the EGC but it will still have some current on it. Fault clearing is a function of time and current. The more current we can get to flow, the quicker the fault will be cleared. The parallel path via the earth will flow a small amount of current and will help the OverCurrent Protective Device to clear the fault. The decrease in trip time as a result of the current flowing in the earth will probably be so small that you can't even measure it.


 
Don, 
agreed here, with one small clarification....


methinks this easier to grasp if we consider said _'fault'_ to be inclusive of the entire ciruit, back to the serving xformer

i bring this up because many of us consider back to the ocpd panel the entire circuit

there's even sone MH pictorals that do not portray this......

~CS~


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## don_resqcapt19

chicken steve said:


> Don,
> agreed here, with one small clarification....
> 
> 
> methinks this easier to grasp if we consider said _'fault'_ to be inclusive of the entire ciruit, back to the serving xformer
> 
> i bring this up because many of us consider back to the ocpd panel the entire circuit
> 
> there's even sone MH pictorals that do not portray this......
> 
> ~CS~


Yes, it is not really clear, but when I use the word souce, that does mean the first upstream transformer that supplies the circuit. That could be the utility transformer or it could be a SDS on the load side of the service disconnect. In some cases it would include other power sources like a generator or a solar system.


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## triden

Grounding helps keep devices at the same potential as the people and objects around the device. The earth may have high resistance, but as long as the device enclosure is at the same potential as the ground, the person touching it won't get a shock. Circuits don't have to be grounded to work, as current flows back to the generator via the neutral in a unbalanced load. If a device is left floating (un-grounded) then potentials can increase in different parts of the circuit due to voltage drops and transients through the conductors.


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## macmikeman

triden said:


> Grounding helps keep devices at the same potential as the people and objects around the device. The earth may have high resistance, but as long as the device enclosure is at the same potential as the ground, the person touching it won't get a shock. Circuits don't have to be grounded to work, as current flows back to the generator via the neutral in a unbalanced load. If a device is left floating (un-grounded) then potentials can increase in different parts of the circuit due to voltage drops and transients through the conductors.



Doesn't jibe with all the buildings I've encountered over the years where the Gec's got disconnected due to construction changes, or rot, or some other reasons and leaving the stucture without a ground. (even taking water piping into consideration - thanks to pvc. No shocking enclosures were present, but changing the 100 amp services to 200 amp ones got em a new rod and water pipe gec.....


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## don_resqcapt19

triden said:


> Grounding helps keep devices at the same potential as the people and objects around the device. ...


It will do that under normal conditions, but under fault conditions a connection to earth does nothing to prevent shock unless you in contact with the earth very close to the grounding electrode.


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## aprillove1719

Ohm's law is an empirical law, a generalization from many experiments that have shown that current is approximately proportional to electric field for most materials. It is less fundamental than Maxwell's equations and is not always obeyed. Any given material will break down under a strong-enough electric field, and some materials of interest in electrical engineering are "non-ohmic" under weak fields.

A ground (earth) mat or grounding (earthing) mat is a flat, flexible pad used for working on electrostatic sensitive devices. It is generally made of a conductive plastic or metal mesh covered substrate which is electrically attached to ground (earth).


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## pistol pete

The water main comes in mighty handy when you lose a neutral from the pole ... whey you lose that you get cabooom. unless you a have a nicely balanced load... it does work well as an emergancy neutral.. the ground rod does work also ...


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## notwerby

InPhase277 said:


> Right. A complete circuit can exist with no ground at all. Just like your car battery works without being connected to ground. The space station in orbit is not connected to ground, yet circuits function normally.
> 
> A circuit is a path from a source, through a load, and back to the source.


 Yes, but in those examples, we are talking DC, not AC. In an AC circuit, as in any circuit, there need to be two different points of contact in order to create a voltage. When you have power transmission lines, you only have 3 hots, no neutral, This is fine for 2 or 3 phase systems, but for single phase, you still need a second point of contact for the circuit to function. This comes from the grounded terminal on the transformer. The difference is, ac is constantly changing direction, so no serious amount of current is actually flowing into the ground, there just needs to be this second contact point in order for the circuit to function properly. If you unground the service, the same thing would happen as if you disconnected the neutral from the service drop. You would lose single phase power. So to say that it is unnecessary to ground, that is incorrect, at least in my understanding. I think there are communication problems going on in these posts as to definitions and language being used.


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## notwerby

oh, and just in case... 

http://www.pacificcresttrans.com/resource-center/15/Grounding-Transformers.html
http://ecmweb.com/bonding-amp-grounding/basics-bonding-and-grounding-transformers


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## brian john

notwerby said:


> Yes, but in those examples, we are talking DC, not AC. In an AC circuit, as in any circuit, there need to be two different points of contact in order to create a voltage.


 Difference of potential



> When you have power transmission lines, you only have 3 hots, no neutral, This is fine for 2 or 3 phase systems, but for single phase, you still need a second point of contact for the circuit to function. This comes from the grounded terminal on the transformer. The difference is, ac is constantly changing direction, so no serious amount of current is actually flowing into the ground, there just needs to be this second contact point in order for the circuit to function properly. If you unground the service, the same thing would happen as if you disconnected the neutral from the service drop. You would lose single phase power. So to say that it is unnecessary to ground, that is incorrect, at least in my understanding. I think there are communication problems going on in these posts as to definitions and language being used.


*WHAT to HECK*

I can run a single phase system ungrounded all day long as a matter of fact in old MCCs it was done all the time with the control transformer or control transformers.

No electrical distribution system needs to be grounded to facilitate operation of utilization equipment, UNLESS the Earth is utilized for the return and this only works at higher voltages and then there would be current flowing in the Earth.


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## macmikeman

I am usually able to completely shut down further posting at all on threads like this one, even if visited by heavyweight experts and moderators, by simply pointing out the doorbell system at your house if it is the wired type is also an ungrounded system, and it remains stable to "ground" under all normal conditions (yeah you can raise the potential on your doorbell system if you cross connect it to a hot conductor from the house wiring... but that don't count, and grounding it won't "stableize" anything if you did that..)


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## Meadow

FWIW, A little off topic but the one of the reasons why a neutral is required to be grounded is because of edison screw base sockets. 

A neutral will still work and clear faults even if ungrounded.

Like others have said, NEC terms are a bit confusing.


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## notwerby

So then where does the neutral come from? Im not talking about what you can and cant do, im talking about how it is normally wired on the average transformer you see on the street. If you trace the neutral wire coming out of someones house, from the service drop, where does it go? 



*WHAT to HECK*

I can run a single phase system ungrounded all day long as a matter of fact in old MCCs it was done all the time with the control transformer or control transformers.

No electrical distribution system needs to be grounded to facilitate operation of utilization equipment, UNLESS the Earth is utilized for the return and this only works at higher voltages and then there would be current flowing in the Earth.[/QUOTE]


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## macmikeman

notwerby said:


> So then where does the neutral come from? Im not talking about what you can and cant do, im talking about how it is normally wired on the average transformer you see on the street. If you trace the neutral wire coming out of someones house, from the service drop, where does it go?
> 
> They hide it in the center of the pole. Then they connected it to a chain that goes down to the center of the planet and anchors the pole to the ground. The whole thing is monitored by current transformers that are intelligent and send the data back to the command center which is located underneath Speedy Petey's house.


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## notwerby

macmikeman said:


> notwerby said:
> 
> 
> 
> So then where does the neutral come from? Im not talking about what you can and cant do, im talking about how it is normally wired on the average transformer you see on the street. If you trace the neutral wire coming out of someones house, from the service drop, where does it go?
> 
> They hide it in the center of the pole. Then they connected it to a chain that goes down to the center of the planet and anchors the pole to the ground. The whole thing is monitored by current transformers that are intelligent and send the data back to the command center which is located underneath Speedy Petey's house.
> 
> 
> 
> 
> 
> whats with the sarcasm? Its a simple question, i didnt say where is the ground, i said where does the neutral go? If its not to the ground, then where?
Click to expand...


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## macmikeman

notwerby said:


> macmikeman said:
> 
> 
> 
> whats with the sarcasm? Its a simple question, i didnt say where is the ground, i said where does the neutral go? If its not to the ground, then where?
> 
> 
> 
> Look here: http://en.wikipedia.org/wiki/Star-delta_systems
> 
> 
> 
> The spelling will be better than mine and it has a picture for you.
Click to expand...


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## McClary’s Electrical

notwerby said:


> macmikeman said:
> 
> 
> 
> whats with the sarcasm? Its a simple question, i didnt say where is the ground, i said where does the neutral go? If its not to the ground, then where?
> 
> 
> 
> 
> 
> There is a system that functions through the earth, as you describe, it's called SWER, (single wire earth return) but it is very rarely used due to it's obvious disadvantages. Most distribution facilitates a grounded conductor.
Click to expand...


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## macmikeman

mcclary's electrical said:


> notwerby said:
> 
> 
> 
> There is a system that functions through the earth, as you describe, it's called SWER, (single wire earth return) but it is very rarely used due to it's obvious disadvantages. Most distribution facilitates a grounded conductor.
> 
> 
> 
> Your quite right, and I am pretty well studied up on SWER systems and where they are most likely to be found.
Click to expand...


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## notwerby

that says on the secondary side it has an "earthed neutral point." What is that? Earth and ground sound similar to me.


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## notwerby

mcclary's electrical said:


> notwerby said:
> 
> 
> 
> There is a system that functions through the earth, as you describe, it's called SWER, (single wire earth return) but it is very rarely used due to it's obvious disadvantages. Most distribution facilitates a grounded conductor.
> 
> 
> 
> 
> Where does that neutral point come from? Even if the utility provides the neutral, it has to eventually be connected to something, somewhere. I dont know if these look like stupid questions to everyone, but i'v yet to get a good answer.
Click to expand...


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## macmikeman

notwerby said:


> mcclary's electrical said:
> 
> 
> 
> Where does that neutral point come from? Even if the utility provides the neutral, it has to eventually be connected to something, somewhere. I dont know if these look like stupid questions to everyone, but i'v yet to get a good answer.
> 
> 
> 
> 
> You need to buy an UGLY's book and look at all the pictures of transformer windings. You can get one at the Home Depot. On a single phase transformer for instance it is merly connected to the midpoint of the winding. It starts there, and at the other end of the circuit is the lightbulbs and such...
Click to expand...


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## McClary’s Electrical

notwerby said:


> mcclary's electrical said:
> 
> 
> 
> Where does that neutral point come from? Even if the utility provides the neutral, it has to eventually be connected to something, somewhere. I dont know if these look like stupid questions to everyone, but i'v yet to get a good answer.
> 
> 
> 
> 
> It's connected to the center tap, and earthed too. But the earth part could be lifted or opened and the system would still functionwithout it.
Click to expand...


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## notwerby

macmikeman said:


> notwerby said:
> 
> 
> 
> You need to buy an UGLY's book and look at all the pictures of transformer windings. You can get one at the Home Depot. On a single phase transformer for instance it is merly connected to the midpoint of the winding. It starts there, and at the other end of the circuit is the lightbulbs and such...
> 
> 
> 
> I have an uglys book, but its in my toolbag at work. Although any picture i'v ever seen of single phase transformer windings, shows the center tap with a ground symbol also. Or if its not split phase, shows one leg of the winding with a ground symbol.
> Im not referring to the uglys book specifically, i cant remember their pictures off the top of my head, but i'v seen diagrams all over.
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## macmikeman

notwerby said:


> macmikeman said:
> 
> 
> 
> I have an uglys book, but its in my toolbag at work. Although any picture i'v ever seen of single phase transformer windings, shows the center tap with a ground symbol also. Or if its not split phase, shows one leg of the winding with a ground symbol.
> 
> 
> 
> 
> That is so the poco can save a few bucks. I'm thinking troll now.
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