NEC 250.52(3) concrete-encased electrode

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iwire said:
Where can I find that thought in description found in 250.52(A)(3). :)

In the same area as this I thing


In my opinion the rebar brought out of a concrete footing is not 'the electrode' the electrode only exists inside the footing near the bottom of the footing.

Or somewhere around there!
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Interesting thoughts, Gentlemen. So it seems that a piece of rebar extending above the slab is not actually part of the electrode because it isn't encased in concrete. Therefore, the rebar stub-up is actually being used as part of the Grounding Electrode Conductor. And 250.62 does not permit steel to be used as the GEC. So rebar stub-ups are literally a violation of the code.
 
crossman said:
Therefore, the rebar stub-up is actually being used as part of the Grounding Electrode Conductor. And 250.62 does not permit steel to be used as the GEC. So rebar stub-ups are literally a violation of the code.
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Yeah cool ain't it? :grin:

I was planing on going into that eventually. :cool:
 
George Stolz and I had a long discussion about that in the past.

If I recall correctly George felt the CEE continued beyond the concrete encasement, my position was that was not possible with the current NEC wording.
 
I'm siding with you bob!

Here's a scenario: If the rebar extended up out of the slab still counts as an electrode... say the electrode rebar stub-up was 100 feet away from the service. Instead of running 100 feet of copper GEC from the stub-up to the service, I could pick up all the left-over rebar scraps and tie-wire them together all the way to the panel and then make the GEC connection with a short piece of copper wire?

Doesn't sound right!
 
I have been toying with this concept for a while. What I have decided to do, and have done in the past, is to install 20 feet of #4 copper in the footer and attach it to the rebar in the concrete-- I then bury the left over copper in the ground curled up where the service will be. So far so good.
 
this is from the article I linked to ,..I am curious ,.. is it common to have electricaly seperate CCEs ? And are they all being bonded ??

1. Are more than a total of 20 feet of reinforcing steel located in a footing required for compliance with Sections 250.50 and 250.52? The 20 feet can include pieces of rebar that are tied together in the usual manner. In other words, if more than 20 feet of reinforcing steel is located in the footing does all of the steel need to be bonded together to form the electrode, or will a minimum of 20 feet of the steel be the maximum length required? This is important to understand as having footings at different levels (step footings) may occur. This also may include concrete pads for the support for interior columns, or many concrete piers to support the entire structure. If all of the steel needs to be bonded together this would require a bonding conductor to jump from one footing to the other and possibly the pads, or to each separate pier.</I>
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Answer: The Code establishes the minimum requisite, which means one is required to do at least that much. The answer is yes; a single section of rebar in a length of 6.0 m (20 ft) satisfies the requirements of Section 250.52(A)(3). The minimum length of 6.0 m (20 ft) can be accomplished by multiple reinforcing bars being bonded together using the usual steel tie wire as indicated in the last sentence of this section. To answer the second part of this question, if there are multiple concrete-encased electrodes in the same overall concrete footing that are not tied together by the usual tie wire, then by the current minimum requirements in the Code, they should be used and bonded together. This situation can be compared to conditions where multiple water pipe grounding electrodes are in the same structure. They all are required to be used in the grounding electrode system, without exception.
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"To answer the second part of this question, if there are multiple concrete-encased electrodes in the same overall concrete footing that are not tied together by the usual tie wire, then by the current minimum requirements in the Code, they should be used and bonded together."

There was an addition to NEC 2008 250.52(A)(3) which states that if there are multiple CEEs in an installation, it is permissible to connect to only one of them. No need to tie them all together.
 
M. D. said:
Thanks ,..my 08 is in the truck ..is there any relief from other multiple electrodes?? like copper water pipes?

I also wanted to share this bulletin from NH. in light of the issue raised by Bob.
http://www.nh.gov/safety/divisions/firesafety/building/electrician/documents/050909_concreteencasedelectrodes.pdf
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Well finally got done reading all of the articles, very interesting indeed. The most of which are figures 4 and 5 at the above link that show a rod extending out of the footing and an underground connection made outside of the footing.

Still don't like it but atleast theres someone that agrees with me.(its about time!)
 
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