# Ground and Neutral bonded at service box



## electricnut

What is the difference in bonding the neutral and ground at the service box as opposed to an auxillary panel, isn't it the same?


----------



## Magnettica

electricnut said:


> What is the difference in bonding the neutral and ground at the service box as opposed to an auxillary panel, isn't it the same?


No, because a grounded "neutral" conductor is a current-carrying-conductor (CCC) in a 2-wire circuit. If neutral and ground were bonded at any place other than at the main breaker you would have current flowing on the normally non-current-carrying parts. You don't ever bond a neutral and a ground at a receptacle in a metal box do you?


----------



## Toronto Sparky

Added to that you would create a unbalanced magnetic field.


----------



## sparks134

you can only bond the neutral and ground only at the main disconnect, if not you can really hurt/kill somebody!!!:no::no:


----------



## electricnut

you can only bond the neutral and ground only at the main disconnect, if not you can really hurt/kill somebody!!!
Hey can you explain why???


----------



## Speedy Petey

The buzz words here are "objectionable current".

http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/ObjectionableCurrent~20020610.htm


----------



## Magnettica

Speedy Petey said:


> The buzz words here are "objectionable current".
> 
> http://www.mikeholt.com/mojonewsarchive/GB-HTML/HTML/ObjectionableCurrent~20020610.htm


Live it, learn it, love it. :thumbsup:


----------



## 220/221

If the neutral and grounds are together in a panel and you _lose_ the neutral feeding that panel, the current will try to flow *thru any available path to ground *trying to find it's way home.

This _could_ energized metal components of anything grounded and attached to the system.


----------



## Toronto Sparky

Toronto Sparky said:


> Added to that you would create a unbalanced magnetic field.


Unbalanced magnetic fields running though a ferris metal raceway could create a condition that will heat up the raceway to the point of fire..


----------



## Stator

Whoever said that the only place you can ground a neutral is the service panel is not correct. What happens if your incoming water piping is non-metallic?? 

Use a ground plate outside right next to the meter, attach the correct size ground to it, then "Ground" the neutral inside the meter base. Pick up a dual lug so that you have room for the house neutral and the ground.

Then remove the bonding strap from the panel, run the ground through your conduit or Teck cable (I much rather use Teck cable) and ground your service panel at the ground bar.

Ok let the bashing begin....:laughing:


----------



## Speedy Petey




----------



## RIVETER

*Unbalanced magnetic fields*



Toronto Sparky said:


> Unbalanced magnetic fields running though a ferris metal raceway could create a condition that will heat up the raceway to the point of fire..


I don't know what you mean. I've never considered "unbalanced magnetic fields", has anyone else?


----------



## cdnelectrician

RIVETER said:


> I don't know what you mean. I've never considered "unbalanced magnetic fields", has anyone else?


Ya, not too sure about that one...but I could see those cheap chinese cast conduit connectors melting away lol I think maybe you mean eddy currents in single conductor cables surrounded by ferrous metal operating above 225 amps.


----------



## EJPHI

RIVETER said:


> I don't know what you mean. I've never considered "unbalanced magnetic fields", has anyone else?


 
This is an important point. 


If the ground and neutral are connected at the main panel or upstream from it (meter base), then the bonded metal only forms a return path when a fault occurs from line to ground.
So if the fault occurs it should be cleared by the overcurrent device. In other words this is a temporary condition.

If you connect the ground and neutral down stream from the main panel as well as in the main panel, all bonded metal becomes part of the path for the neutral current. This is not a temporary condition, as described above, and it will have two direct consequences:
1) The current flowing through the bonded metal will cause it to warm up due to resistive heating.
2) Since the line and neutral return paths are not "tight" like they would be if all of the return current flowed in the neutral wire in the same reaceway or cable as the line wire, a wide-area magnetic field is formed. This field will induce currents in the bonded metal or any other conductor forming a closed path that encircles part of the wide-area magnetic field. The induced current will cause the metal to heat up. Eddy currents will also cause heating even if the metal does not encircle the magnetic field

I expect that there isn't enough current in most resi branch circuits to cause noticable resistive or inductive heating with improper ground/neutral connections. You might notice that an AM radio has a lot 60 Hz hum when tuned off station. Kinda like the first three way I wired:jester:
Because the small voltage drop across the metal sharing the neutral current, there wouldn't even be any touch potential.

EJPHI


----------



## RIVETER

Trick or treaters at the door...gotta go.


----------



## Stator

Speedy Petey said:


>


Exactly. Then run a ground to the service and remove the bonding strap. Land the ground at one of the ground bars. :thumbsup:


----------



## RIVETER

Toronto Sparky said:


> Added to that you would create a unbalanced magnetic field.


I am still not with you,there.


----------



## RIVETER

*Picture*



Stator said:


> Exactly. Then run a ground to the service and remove the bonding strap. Land the ground at one of the ground bars. :thumbsup:


 Am I the only one who does not understand this pictorial?


----------



## bobelectric

Speedy Petey said:


>


 I never saw a ground point at the service head. If it was up to me,all service entrances would have the meter with the main breaker with all grounding outside for lightning protection with the ground rods. And shut off for fire safety.


----------



## EJPHI

bobelectric said:


> I never saw a ground point at the service head. If it was up to me,all service entrances would have the meter with the main breaker with all grounding outside for lightning protection with the ground rods. And shut off for fire safety.


 
I am 100% with Bob on this.

On the one hand what could be difficult about connecting a silly green wire? But as you look into all apsects of grounding and bonding, you can see that there is a lot of thought behind the NEC.

EJPHI


----------



## RePhase277

RIVETER said:


> Am I the only one who does not understand this pictorial?


The pic is illustrating the points at which the NEC allows the neutral/ground bond. Only one is allowed per system. It can occur at the service drop (a very rare beast indeed), or in the meter socket (if the AHJ or POCO allows it), or more commonly in the first disconnecting means.


----------



## sparks134

your not supose to use a green wire or tape!!


----------



## kbsparky

InPhase277 said:


> The pic is illustrating the points at which the NEC allows the neutral/ground bond. Only one is allowed per system. It can occur at the service drop (a very rare beast indeed), or in the meter socket (if the AHJ or POCO allows it), or more commonly in the first disconnecting means.


In most areas, bonding of the neutral occurs at _two_ places: In the meter box, _and _at the service disconnecting means. This is due to the designs of most meter box enclosures: The neutral terminal is not isolated from the enclosure. Since most power companies do not allow for access once energized (they seal the meter boxes), they also do not allow for the grounding electrode conductor to be present in there.

Therefore, it can be standard practice to bond the neutral at the service disconnect, and from that point on, the neutrals and grounds are kept separated. :whistling2:


----------



## RIVETER

*lGrounding at service head*



bobelectric said:


> I never saw a ground point at the service head. If it was up to me,all service entrances would have the meter with the main breaker with all grounding outside for lightning protection with the ground rods. And shut off for fire safety.


In some rural areas the EGC is attached to the neutral at the drip loop...My cabin is that way. It does make sense, as Bobelectric said, to ground the neutral outside of the premises. Why bring the lightning INSIDE only to take it back outside?


----------



## Stator

RIVETER said:


> In some rural areas the EGC is attached to the neutral at the drip loop...My cabin is that way. It does make sense, as Bobelectric said, to ground the neutral outside of the premises. Why bring the lightning INSIDE only to take it back outside?


True. Also don't forget all new homes (in my area anyways) all have plastic water piping. Grounding the neutral at the meter base is the way I like to do it. Plus if your installing a lets say 5 gang meter base for a town home complex, you can now ground the neutral at the meter base like I stated. Then run Teck cable to all the units and you save on having to run your main grouind to the water pipe (If it is metal of course). All you would need is a small peace of ground to basically just jump the water meter from house side to street side, and of course the gas line. 

Put's some more money in our pockets! :thumbsup:


----------



## FFesta

220/221 said:


> If the neutral and grounds are together in a panel and you _lose_ the neutral feeding that panel, the current will try to flow *thru any available path to ground *trying to find it's way home.
> 
> This _could_ energized metal components of anything grounded and attached to the system.


Are ground wires required by code?
The appliance will operate normally without the *ground wire* because it is not a part of the conducting path which supplies electricity to the appliance. ... The U.S. National Electric *Code* Article 250 requires that the *ground wires* be tied back to the electrical neutral at the service panel.


----------



## Kevin

FFesta said:


> Are ground wires required by code?
> The appliance will operate normally without the *ground wire* because it is not a part of the conducting path which supplies electricity to the appliance. ... The U.S. National Electric *Code* Article 250 requires that the *ground wires* be tied back to the electrical neutral at the service panel.


Dude really? You posted the same thing, word-for-word, on two different posts, one of which is nearly 12 years old?

Fill out your profile please. It's required. Below is a link with instructions.









IMPORTANT: Required Profile Fields


Please add your Electrical Trade in your account settings. From the navigation, near the upper right-hand corner, click on your avatar to open the drop-down menu and select “Account Settings”. The scroll down to Electrical Trade. Fill in the information for your trade and click Save at the...




www.electriciantalk.com


----------

