# Neutral questions



## henderson14 (Oct 23, 2010)

1. If the neutral is grounded the same as the ground wire, then why doesn't the neutral short the circuit the way a ground does if you touch it to the hot?

2. Why are there 3 hots (in commercial) to one neutral if the neutral carries almost no current? Shouldn't it be able to support many more hots?


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## Dennis Alwon (May 9, 2009)

henderson14 said:


> 1. If the neutral is grounded the same as the ground wire, then why doesn't the neutral short the circuit the way a ground does if you touch it to the hot?
> 
> 2. Why are there 3 hots (in commercial) to one neutral if the neutral carries almost no current? Shouldn't it be able to support many more hots?



If you touch the neutral to the hot it will short the circuit.

The neutral carries the unbalanced load. In a 3 phase system it is possible for the neutral to carry 20 amps so if there were wires on the same phase the neutral would be a cumulative affect .


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## McClary’s Electrical (Feb 21, 2009)

Calculate as follows


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## henderson14 (Oct 23, 2010)

Dennis Alwon said:


> If you touch the neutral to the hot it will short the circuit.
> 
> The neutral carries the unbalanced load. In a 3 phase system it is possible for the neutral to carry 20 amps so if there were wires on the same phase the neutral would be a cumulative affect .


So why can't the ground be used as a neutral if they are both grounded?


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## McClary’s Electrical (Feb 21, 2009)

henderson14 said:


> So why can't the ground be used as a neutral if they are both grounded?


The neutral should only complete the circuit. The ground should be connected to all metal parts for safety. 
If you mix those two, say, connect a neutral to metal parts, and then you have a loose neutral connection somewhere, all metallic parts in that entire circuit would become energized to FULL LINE POTENTIAL.


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## henderson14 (Oct 23, 2010)

mcclary's electrical said:


> The neutral should only complete the circuit. The ground should be connected to all metal parts for safety.
> If you mix those two, say, connect a neutral to metal parts, and then you have a loose neutral connection somewhere, all metallic parts in that entire circuit would become energized to FULL LINE POTENTIAL.


So then what is the neutral ground to? I thought it was also grounded to metal. 

ALso, how would a loose neutral engerise metallic parts if the neutral normally carries no current?


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## Big John (May 23, 2010)

henderson14 said:


> So why can't the ground be used as a neutral if they are both grounded?


 In addition to what Mcclary said, when you mix neutrals and grounds you end up putting neutral current flow on all your grounded metal surfaces.

This can create a mild shock hazard even under "normal" operating conditions, and I've fixed a couple cases where this was happening to people.


> ...So then what is the neutral ground to? I thought it was also grounded to metal....


 The neutral is only grounded at one point in any electrical system, this prevents a complete circuit and prevents current flowing anywhere else but on the neutral conductor.


> ...So, how would a loose neutral engerise metallic parts if the neutral normally carries no current?


 If a neutral wire is present in a system it almost always carries current. And any time you have neutral current, you have the potential to develop voltage.

In a single phase, single conductor system it is the only current return path and carries as much current as the hot.

In a split phase, or three phase system, it carries the unbalanced load. Sometimes this is as much current as is flowing on any single hot conductor, sometimes in cases of severe triplen harmonics it's _more_ current than is flowing on any single hot conductor, but very rarely are loads balanced so well that no current flows on the neutral.


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## McClary’s Electrical (Feb 21, 2009)

henderson14 said:


> So then what is the neutral ground to? I thought it was also grounded to metal.
> 
> ALso, how would a loose neutral engerise metallic parts if the neutral normally carries no current?


In a single phase circuit, the neutral carries the exact same amount of current as the hot wire. 

In a multi wire branch circuit, (of a single phase service) the neutral carries the unbalanced load of the two hot wires. If a phase is pulling 20 amps, and b phase is pulling 2 amps, the neutral is carrying 18 amps. 

In a 3 phase multi wire branch circuit, it's calculated by the formula posted above.


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## RIVETER (Sep 26, 2009)

Henderson, keep asking the same questions until you feel you are totally understanding of the proper answers. I think they are great questions.:thumbsup:


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## RIVETER (Sep 26, 2009)

henderson14 said:


> So then what is the neutral ground to? I thought it was also grounded to metal.
> 
> ALso, how would a loose neutral engerise metallic parts if the neutral normally carries no current?


The neutral is only attached to metal portions of the system at the service...and only there. At that same point the GROUND wire from the Rod is connected as well. That is why we say that the neutral is "grounded". From the service/breaker panel the equipment grounding conductor...bare, or green is attached to the ground buss in the panel and then goes with the hot and the neutral to the devices that it supplies. The bare/or green wire is the egc and is physically attached to the boxes in a system and is bonding them all together. Since the egc goes back to the panel and is attached to the ground buss AND the ground buss is attached to the Neutral IN that panel, if a HOT wire for some reason comes into contact with any metal part of the system current will flow on the egc and will cause a high current to trip the breaker of that circuit.


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## A Little Short (Nov 11, 2010)

henderson14 said:


> 1. If the neutral is grounded the same as the ground wire, then why doesn't the neutral short the circuit the way a ground does if you touch it to the hot?
> 
> 2. Why are there 3 hots (in commercial) to one neutral if the neutral carries almost no current? Shouldn't it be able to support many more hots?





henderson14 said:


> So why can't the ground be used as a neutral if they are both grounded?





henderson14 said:


> So then what is the neutral ground to? I thought it was also grounded to metal.
> 
> ALso, how would a loose neutral engerise metallic parts if the neutral normally carries no current?


These are great questions if you are just starting out and trying to learn.
I sure hope you are an apprentice or helper trying to learn.

I'm not trying to "belittle" you or anything but your profile concerns me.



> About henderson14
> What is your electrical related field/trade:
> *electrician
> *Location chicago


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## RIVETER (Sep 26, 2009)

A friend of mine in need of work hired on as a new garbage man for the city. He called himself a "GARBAGE MAN". What's the diff?


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## wildleg (Apr 12, 2009)

RIVETER said:


> A friend of mine in need of work hired on as a new garbage man for the city. He called himself a "GARBAGE MAN". What's the diff?


you can't wire garbage the wrong way and kill people.(generally)


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## A Little Short (Nov 11, 2010)

RIVETER said:


> A friend of mine in need of work hired on as a new garbage man for the city. He called himself a "GARBAGE MAN". What's the diff?



Would you let the same guy operate on you if he called himself a "Doc"?:whistling2:


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## Big John (May 23, 2010)

wildleg said:


> you can't wire garbage the wrong way and kill people.(generally)


 I'm not sure why I think that's so damn funny, must be time for me to get some sleep.


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## Fibes (Feb 18, 2010)

RIVETER said:


> A friend of mine in need of work hired on as a new garbage man for the city. He called himself a "GARBAGE MAN". What's the diff?


 
Learning to say "mone back" may take some talent but it isn't quite as hard as learning electrical theory.


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## amigi968 (May 24, 2008)

Nothing really to add as everything has been answered, but I sure hope this "electrician" is an apprentice in the first 12 months of his trade.


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## dave91 (Jan 8, 2015)

*over your haed*

if you are asking these questions you best go back to school


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## dave91 (Jan 8, 2015)

dave91 said:


> if you are asking these questions you best go back to school


I thought this was a forum for professionals only


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## Dennis Alwon (May 9, 2009)

dave91 said:


> I thought this was a forum for professionals only


The forum is here to help members who are learning. If we all knew everything then there would be no need for a forum. Telling those who want to understand and better themselves non professional is not helpful.


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## Bad Electrician (May 20, 2014)

dave91 said:


> if you are asking these questions you best go back to school


There are aspects of the trade many do not know, from basics to more complicated topics, do you think you know it all? If you do you are either one of the smartest electricians I have had the privilege of meeting or full of baloney!

My belief on this forum is to answer all questions, now if the poster was to continuously argue a point and experience, code or logic proves him wrong then I might get a little testy.


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