Metal pole Neutral to Earth (Ground Rod) to pole?

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Dave D'Amato

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Question....

In reading the NEC code on metal objects not carrying current I'm having difficulties understanding the following....

From the Service power Meter, our construction staff has been terminating Neutral; to ground on the load side. Then this feed is brought to our field service cabinet and tied to another ground rod... All of which we feel is causing power and ground loop issues...

In discussing with these folks, the reply is it's code.... The NEC articles seems to state otherwise....

I can understand the line side of Neutral to ground terminations but no on the load side... Is this reference to code correct?

If so, this depicts Neutral and Earth ground are as one and if this is the case then why install/run a Black (HOT), Neutral (WHITE) and Ground (Green) conductor where two are electrically the same....

This just doesn't seem correct to me....

Thanks,

Dave
 
It's all sevice equipment until you leave the first disconnect. Your neutral is used to ground the metal parts of your service. The earth ground rod (grounding electrode) also terminates there.
When you leave the first disconnect that is when you need the equipment ground (green)
 
The basic rule would be 250.94 which prohibits a neutral(grounded) connection to grounding other than at the service. If I understand what you say, you have that "bond" at your service point (service panel/meter).

But 250.32 makes it a bit more entailed. Prior to the 2008 Code you could feed one structure (field service cabinet) and not use an equip ground, but re-ground your neutral there. As of the '08 Code a seperate eguip. must be installed.

I am assuming here your (field service cabinet) is similiar to a "JOB TRAILER".. with a panel, etc. If it only a metal cabinet, then the equipmet ground would need to be installed, seperate from the neutral (grounded)

A supplemental ground can be added to the equ. ground as desired.
 
Do you think GEC should be line side of the meter:confused:

Maybe I read this wrong. Doesn't matter if you have a second ground source at the panel, you could have 10 for that matter????
 
Metal pole Neutral to Earth (Ground Rod) to pole?

augie47 said:
The basic rule would be 250.94 which prohibits a neutral(grounded) connection to grounding other than at the service. If I understand what you say, you have that "bond" at your service point (service panel/meter).

But 250.32 makes it a bit more entailed. Prior to the 2008 Code you could feed one structure (field service cabinet) and not use an equip ground, but re-ground your neutral there. As of the '08 Code a seperate eguip. must be installed.

I am assuming here your (field service cabinet) is similiar to a "JOB TRAILER".. with a panel, etc. If it only a metal cabinet, then the equipmet ground would need to be installed, seperate from the neutral (grounded)

A supplemental ground can be added to the equ. ground as desired.
Click to expand...

I want to be perfectly clear on what you are saying here so that I fully understand you. Are you saying that if I am on a job site, and the pole feeds a transformer that feeds a standing 400 ampere service, that the nuetral is bonded to grounding, then, if I were to feed a 100 ampere, exterior panel on a Job Trailer via 02/4 cable, that you would not drive a grounding rod at the Job Trailer, and bond the Nuetral to the panel at the Job Trailer? Would you add a grounding rod at the Job Trailer and just connect it to the same bar as the grounding wire in the #02/4 cable? Is this what I am understanding you to say?
 
If you are feeding a job trailer, I would apply 250.32. In the 2008 Code that would require installing an equipment ground and a grounding electrode system at the trailer and bonding it to the panel and the eq. ground.
In Codes prior to 2008, the neutral could possibly be used as the EG also, but the grounding electrodes would still be needed
 
Metal pole Neutral to Earth (Ground Rod) to pole?

augie47 said:
If you are feeding a job trailer, I would apply 250.32. In the 2008 Code that would require installing an equipment ground and a grounding electrode system at the trailer and bonding it to the panel and the eq. ground.
In Codes prior to 2008, the neutral could possibly be used as the EG also, but the grounding electrodes would still be needed
Click to expand...



Thank you so much for your quick, and precise response. It is appreciated.
 
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