Grounding

Status
Not open for further replies.
V

vptim

Member
Gentlemen,
I hate to even ask this, but maybe I need to re-educate myself.
We installed a 200 Amp service in a new single family dwelling. We used the underground copper water pipe for our grounding electrode(250.52). We then installed an 8' Ground rod as a supplementary grounding electrode(250.54). When our electrical inspector came to inspect, he violated our service due to improper grounding. He stated the violation as "additional ground rod required or proof of a test that the 25 ohms of resistance or less are met"(250.56).
Our understanding was that if we used the underground water piping as a primary grounding electrode, and augmented that with a ground rod, the resistance requirements for the rod did not have to be met(250.54).
Are we correct in our installation and understanding of the code? Or do we need to augment another electrode?
Thanks in advance to your response to our question.

VPTim
 
Re: Grounding

I agree with the Inspector. The key terms are "supplemental" and "augmented."

250.53(D)(2) says that if you use the water pipe, then you need a "supplemental" electrode. It goes on to say that if you choose a rod as the supplemental, then 250.56 will apply. 250.56 says that the rod must be under 25 ohms, or it must be "augmented" by a second rod.
Originally posted by vptim:Our understanding was that if we used the underground water piping as a primary grounding electrode, and augmented that with a ground rod. . . .
Click to expand...
My emphasis on the word "augmented." You didn't "augment" with the first rod, you "supplemented." You still need to "augment."

Isn't our language wonderful? ;)
 
Re: Grounding

Gee, I wonder why the inspector didn't want proof that the water pipe was actually in contact with the ground for more than 10'.

He'll probably want you to prove the ground rod you used was in fact 8' long.

Any way to prove the wire you used was made from aluminum and/or copper, he'll probably want certifications of that too.

Dnk.....
 
Re: Grounding

Originally posted by Dnkldorf:
He'll probably want you to prove the ground rod you used was in fact 8' long.
Click to expand...
Why not? The inspectors around here frequently have 4' ground rods in the back of their trucks, after giving them a tug to see how long they were. :)
 
Re: Grounding

While I agree with the driving another rod, I don't agree with the inspector putting the burden of proof upon the electrician to say he must first prove it's not a violation. I believe the burden of proof should always lie upon the inspector to show the installed rod does not meet the minimum of 25 ohms then he can require the additional rod. This is the way the code is writen
"that does not have a resistance to ground of 25 ohms or less shall be augmented by one additional electrode"
It does not say if I can't prove it has a resistance less then 25 ohm's drive another rod?
 
Re: Grounding

It's not really in the scope of the code to mandate whom is responsible to prove what. The code simply states what is to be met, the state or local legislator mandates how compliance is determined.

For example, I agree that on a typical installation it is not the contractor's responisiblity to prove to the inspector a job is compliant. It is the inspector's responsibility to prove the inspection is not. However, on performance issues, the contractor IS responsible to show compliance. Take for example emergency systems. It is the contractor's responsibilty to show the system performs within the specifications of the job and per all applicable codes.

The ground rod issue is a fine line. It is the inspectors responsibility to show the installations is not complaint, however the performace of that installation may indeed be the responsibility of the contractor if the inspector calls the performance into question.

I know some of you guys aren't going to like to hear that, but that is the reality of things, at least here in Florida.
 
Re: Grounding

Originally posted by bphgravity:
I know some of you guys aren't going to like to hear that, but that is the reality of things, at least here in Florida.
Click to expand...
I imagine I am one those 'guys'. :)

How the actual inspection process is done is really up in the air.

I have had inspectors who are entirely self sufficient and I have had others that screamed at me that it was not their job to push the test button on an EBU. One guy will borrow a ladder to see what they want the next guy wants a chauffeur driven scissor lift available. :roll:

As far as the 25 ohms I look at that the same as the rough inspection. It is my job to have the inspector on site when they can see the work. It is not the inspectors job to show up with an xray machine to look inside the walls after Sheetrock is installed.

If I want to drive only one rod I feel I would have to have a tester at hand to demonstrate the one rod meets code.

Bob
 
Re: Grounding

i have to wonder how many people that drive two rods don't actually drive the same 8' rod caught in half.

in reality, that might well be better than 1 eight foot rod. but not to code.
 
Re: Grounding

Bryan, like Bob, I also agree with you. It is definatly the electricians responsibility to provide the test results.

We have to provide F/A certifications, Equipotential test results, Isolation Panel test results, Megger results, Lightning Protection NRTL listing, (as an assembly) High Pot test results, Seismic compliance, (Sealed design and installation) etc..., why would, and how could, an inspector or AHJ possibly have all this equipment and/or training to use it, not to mention the time it would take?

I would say proving the rods resistance would be our responsibilty too, so it is cheaper to sink an second rod and go to the next job.

We only take the time to drag out a test set when it is required in the specs, (state jobs :roll: ) or for performance grounding on certain installations.

Roger

[ September 05, 2005, 06:53 PM: Message edited by: roger ]
 
Re: Grounding

Thanks for all your input.

We installed the second rod without question. We just wanted to educate ourselves for the future.

Thanks,

VPTIM
 
Status
Not open for further replies.
Top