encased grounding

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cj1111

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am i reading the code wrong? i am being told by an inspector i have to have a concrete encased grounding electrode instead of ground rods?
the way i understand 250 is i have several options to ground my service. one of which is to encase in concrete or ground rods or building steel etc...
help
 
250.50 specifies that each item in 250.52(A)(1) thru (A)(6) shall be bonded together to form the grounding electrode system, where those electrodes are available. If you have a concrete encased electrode that meets 250.52(A)(3), you do have to use it along with any other available electrodes.

Normally in a residence, you are only going to have (A)(1) available but 250.53(D) requires you to supplement this with another electrode, normally a rod. I threw that in since you didn't specify resi or commercial.
 
Re: encased grounding

cj1111 said:
am i reading the code wrong? i am being told by an inspector i have to have a concrete encased grounding electrode instead of ground rods?
the way i understand 250 is i have several options to ground my service. one of which is to encase in concrete or ground rods or building steel etc...
help
Click to expand...

Yup! This is clarified in the latest code - if a concrete encased electrode (rebar to us regular folks) is available you have to use it. 250.50 says "all grounding system electrodes as described in 250.52(A)(1) through (A)(6) that are present" must be connected. If you have rebar, you gotta ground it. If you've grounded the rebar, then you can argue that you don't need a ground rod because the footing rebar is a better ground than a rod.

Typical ground rod resistance might be 25 ohms, typical Ufer ground resistance might be 5 ohms.
 
residential

residential

sorry it is residential. so what you are saying is that i have to ground to the rebar and drive a ground rod?
 
You are not required to drive a ground rod if you have a concrete encased electrode. But if you do, you must now use it because it is available.

One of the biggest electrical myths in my area is that you are required to have two sources of ground, I believe that this originated from 250.53(D)(2).

Chris
 
raider1 said:
One of the biggest electrical myths in my area is that you are required to have two sources of ground, I believe that this originated from 250.53(D)(2).

Chris
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I hear this a lot as well. :?:
 
where????

where????

where do you see that you do not have to drive a rod if you encase in concrete?? thanks again
 
cj1111 Posted:
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where do you see that you do not have to drive a rod if you encase in concrete?? thanks again

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If you look at 250.53 (D) (2) Supplemental Electrode Required.
A metal under-ground water pipe shall be supplemented by an additional electrode of a type speciied in 250.52 (A)(2) THROUGH (A)(7).
The reason for the rod is to supplement the metal underground water pipe.

So if you have a metal underground water pipe you would have to supplement it with any other electrode in 250.52(A)(2) through (A)(7)
and 250.52 (A)(3) is a concrete encased electrode. That would be your Supplemental thats is required.
Click to expand...
 
I would add that if you don't have 10' of buried metal water pipe than you only need the Concrete Encased Electrode if the CEE is available.
 
With 2002 is this area, If the rebar was not exposed, you were instructed to drive 2 Ground rods instead. In 2005, the wording was changed to politly tell you that the rebar WAS availible and WILL be used. If you can't find it, get out "Big Bertha" and start chipping. On an existing house, you do not need to find it. Two ground rods here.
 
The Chief Electrical Inspector told me they were not enforcing the rebar requirement on houses. I don't do residential work so it does not affect me, but I bet those that do are happy.
 
iwire said:
hardworkingstiff said:
The Chief Electrical Inspector told me they were not enforcing the rebar requirement on houses.
Click to expand...



Why? :?
Click to expand...

Yea, surprised me too. They said the electrician didn't have control of the footing (or something like that, I didn't really pay attention because I don't residential work). It seemed more like they didn't agree with it.

BUT, they won't get off of than d@mn junction box thing in 555.12! :x
That one affects me.

(edited for spelling)
 
Not enforced is not the same thing as "not required". Make sure that the jurisdiction in which you are working has removed the concrete encased electrode requirement during their code adoption process. If they have not, and you do not use the concrete encased electrode as part of your grounding electrode system, then you will be liable in the event that there is a fire or somewhat gets hurt.
The inspector can decide not to look at some things, but he cannot just eliminate code requirements unless he is also the AHJ and gives you written permission.
 
Re: encased grounding

One thing that might make life easier for everyone is if we make more of an effort to get our nouns in order. I'm not implying lile001 isn't aware of the following, but it's an example for clarity's sake:

lile001 said:
If you have rebar, you gotta ground it.
Click to expand...
The rebar is grounding the service, not the other way around. Mix this word-reversal in with some other aspects of grounding, and pretty soon, some folks could have the cart before the horse. Just a thought. :)

lile001 said:
If you've grounded the rebar, then you can argue that you don't need a ground rod because the footing rebar is a better ground than a rod.
Click to expand...
We aren't given relative rules. If any of the electrodes in (A)(1) through (A)(6) are present, they must be used. If you drove a ground rod, for whatever reason, then technically speaking you must use the ground rod too.

The reason we aren't required to drive a ground rod if we have a CEE present is as was stated above, a CEE doesn't require a supplementary electrode. "Because code doesn't require it." That's the answer, IMO.

The change to 250.50 was to cure another batch of relativism that was rampant throughout the country: that a CEE was relatively unavailable.
 
I wish I could get the inspectors in my area to come to this site. Then again, I wish at least one or two of them would bother to read the code book once in a while also. This morning I was on the phone with one who is sending me back to a job because he wants me to add a ground rod to a service I just did. I had put in a CEE, and also ran a H2o electrode conductor. Both were #2 (I had #2 in truck, could have used #4). I tried to explain that the rod is not required by 2005 when you put in a CEE , but he informed me that it is, "now the code wants us to have all three". So then I reply (eyes rolled up) "ok, since the code wants us to, I will be happy to go back and add it. By the way is a single run of #6 over to the rod ok with you? Answer- " No, it has to be a #4 and it has to go to the water pipe first and then over to the rod.You can't run individual runs to ground electrodes. And also it has to be solid. Me again - " Is there some local amendment I never heard about that dictates all this stuff you are saying? If so I would love to get myself a copy of it in order to be able to comply with all these requirements that I never had to do before."
Answer- "Its all in the code, just do it like I am telling you to." End of conversation.

Edit - I left out some details, 200 amp service,#2 thhn/thwn copper gec's used. Another inspector was there before the pour and saw the CEE. I used a listed clamp. My H2O clamp (accesable above grade) was listed for direct burial also.
 
Your inspector could use some continuing education training. Unless he's got a local requirement for what he's saying, he doesn't have a clue. I would suggest Mike Holt's Grounding vs. Bonding book for him. The illustrations are very clear. Enough so, that even this guy should be able to understand them.
 
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