How can I get an official interpretation of a specific NEC section?

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Electron_Sam78

Electron_Sam78

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Palm Bay, FL
I'm arguing with a contractor at work that he has to install a GES at a new building that is supplied by a feeder about 700 ft away from the service. The service is a shed that has a panelboard in it that supplies RV pedestal circuits and the building in question. They say that the building, which has a metal water piping system btw, doesn't need a GES installed according to 250.32 since it was supplied with a GEC. They even point to that section in their argument. I pointed this out to the QA ispector and they have come to the conclusion that it comes down to interpretation of the code and that I am wrong. This is unbelievable!! Is there any way I can get an offical interpretation by the writers of that code section for this situation?
 
See Section 6 of this document.. The process can take six months or more.

There is no question that if you have a second building served by a feeder that you need to install a grounding electrode at the second building and, under the 2008 code, run an EGC from the source building to the second building.
 
Jim W in Tampa said:
Are you the EC that is wiring the job ?
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No I'm just an electrician that works on the property where this is taking place. Our company is having some contract work being done including this building, which is one of many being installed all with GESs. Our QA on the job doesn't know the code well enough to spot these kinds of things and sides with the contractor more often than not...strangely enough.
 
Jim W in Tampa said:
I will assume it will be permitted and the prints will like spec a grounding system. Personally i would want rods.
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I work for the Army Corps of Engineers and the property it is not under the jurisdiction of any other inspecting authority.The Corps is it's own AHJ. It's a design build where the contractor comes up with the design and it is approved by the USACE. The contract states that they shall comply with all building codes including the NEC - from what I'm told any way.
 
Electron_Sam78 said:
Wow is there a template on how to write one of these requests?
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Don't know of any, but that doesn't mean there isn't one somewhere :)

Another thing you should understand about formal interpretaions is that the AHJ still has the final say, and do not have to agree with the formal interpretation.

Ask the QA inspector if he'll consider our interpretation?

In your OP it sounds like the QA inspector is considering the EGC run with the supply conductors a GEC. It is an EGC, as required by 250.32(B).

You mentioned metal water piping but did not say whether or not it is bonded to the feeder's grounding conductor...???
 
Electron_Sam78 said:
Wow is there a template on how to write one of these requests?
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You can get an informal interp from the Senior Electrical Engineers/Specialists with the NFPA but you have to be a member of the NFPA to do so I believe. You may wish to request someone who is a member to write for an informal request for you as well.
 
I'm not sure what you mean by GES.

WHy couldn't (wouldn't) the water pipe be the grounding electrode?
Aren't you going to bond it?
 
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realolman said:
I'm not sure what you mean by GES.

WHy couldn't (wouldn't) the water pipe be the grounding electrode?
Aren't you going to bond it?
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GES is short for Grounding Electrode System. The metallic water pipe would have to be used and supplemented with at least one other Grounding Electrode

Roger
 
radiopet said:
You can get an informal interp from the Senior Electrical Engineers/Specialists with the NFPA but you have to be a member of the NFPA to do so I believe. You may wish to request someone who is a member to write for an informal request for you as well.
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And how is that any better than what you find here or other places? I would accept a FI or a published panel statement as authoritative, but would only take the informal one as advisory. Also, Smart said, the AHJ is the final authority, short of the court system.
 
Smart $ said:
Ask the QA inspector if he'll consider our interpretation?

In your OP it sounds like the QA inspector is considering the EGC run with the supply conductors a GEC. It is an EGC, as required by 250.32(B).

You mentioned metal water piping but did not say whether or not it is bonded to the feeder's grounding conductor...???
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I wrote an explanation of 250.32 that was over a page long explaning why 250.32 required a GES. I even included quotes from article 100 defining feeders and branch circuits and broke down the whole section. :mad:

Yes I assume since an EGC was run, it complies with 250.32(B). Why? :confused: That's not the point of 250.32(B) anyway. It just says one is required and focuses on how to terminate it relative to the grounded conductor and the GEC (which btw assumes compliance with part (A) ).

The water piping is not bonded or used as a GE. :mad:

I'm really ticked at these guys. They're supposed to be professional electrical contractors and they don't even know the codes. If they do they're trying to get away with crap work. I'm also ticked at the USACE for letting them get away with it. :mad:
 
Electron_Sam78 said:
I work for the Army Corps of Engineers and the property it is not under the jurisdiction of any other inspecting authority.The Corps is it's own AHJ. It's a design build where the contractor comes up with the design and it is approved by the USACE. The contract states that they shall comply with all building codes including the NEC - from what I'm told any way.
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A little off topic but I would like to ask. What dose the Corps use as a guide? The NEC or what? The reason I ask I talked to a contractor who is doing a large job on an army base. They have the cans set for there panel boards but a inspector for the corps. told him they would not pass the install because the cans did not have a sticker stating "service entrance rated" :-? .The guts are not in the can yet and they are what is requried to be listed not the can. Where do they come up with there guidelines?
 
On military installations the AHJ is usually some government appointed person or agency. When I was in the Air Force the engineers and actual electricians in the Civil Engineering Squadron were the AHJ. In the USACE they use the current NEC or so I'm told. On design builds the contractor will design and submit plans. They are reviewed and approved by a group of people including engineers. But the contracts also state that they will conform to local and national building codes. Now the level of knowledge that the on-site inspectors have probably varies. Im pretty sure that the ones we have know jack about the NEC and I have no idea about the people that review and approve the contractor's plans. It's kind of scary and ridiculous considering our tax dollars are paying for this substandard work.
 
Electron_Sam78 said:
Has anyone requested an official interp and be willing to email me a copy? I don't even have a clue as to how to word or format something like this
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Formal Interpretation request form

Formal Interpretations (pdf) from "NFPA 70: National Electrical Code" web page. There are only 2 which concern issues under 1981 and 1999 editions :confused:

Quoted from NFPA website... "For previously issued Formal Interpretations (not listed below), e-mail the NFPA Library, or call +1 617 984-7445, or fax +1 617 984-7060."
 
Smart $ said:
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Formal Interpretations (pdf) from "NFPA 70: National Electrical Code" web page. There are only 2 which concern issues under 1981 and 1999 editions :confused:

Quoted from NFPA website... "For previously issued Formal Interpretations (not listed below), e-mail the NFPA Library, or call +1 617 984-7445, or fax +1 617 984-7060."
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I don't know why those two FIs exist. The NFPA rules require that the text that resulted in the FI be clarified in the next edition of the document.
6.6 Action Following Issuance of Formal Interpretation. Any TC whose Document has been the subject of a Formal Interpretation shall prepare a committee proposal clarifying the text of the Document involved. The TC shall process such a proposal in conformance with procedures set forth in 4.3. After issuance of the next edition of the document, the Interpretation shall be retired.
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roger said:
....The metallic water pipe would have to be used and supplemented with at least one other Grounding Electrode

Roger
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It seems to me that the GEC and the waterpipe would certainly serve the purpose, but I see that you are correct that it needs a supplemental electrode according to 250.53.(D)(2).

.... what is 250.54 telling us? I don't understand what it's for.


It seems to me to say that, for one thing, that you don't need two ground rods, or that it has to be 25 ohms.

Looking at 250.118 ( which is referred to in 250.54 ), I don't suppose that it could be taken to mean the electrode back at the supplying service , connected to the GEC that is run to the new structure would be good enough?

It almost seems like if you didn't have the water pipe, you'd need two ground rods, but since you have the waterpipe, maybe you could argue through 250.54 , that the rod back at the supplying service would be enough.

I'm looking at the 2005.
 
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