Concrete Encased Electrode

[George Stolz]

Re: Concrete Encased Electrode

Originally posted by physis:

I just remember Allen griping about his ufer's getting cut off--if that happened after the pour, he still has 20' of #4 in the concrete, he still has his ufer. He just needs to pull his GEC to it.

I thought that was solved for Allen four or six monthes ago. Did he forget.

 

[physis]

Re: Concrete Encased Electrode

I reread your post too Don. I should have paid more attention the first time.

 

[benaround]

Re: Concrete Encased Electrode

George,

I think you are basing a lot of your thinking on that rebar that is turned up,and allowing a connection after the fact.

Other states do not see where this is the written word ie. Concrete Encased,and the connection(s) are made at the time of installation and are in fact concrete encased also.

So,the CEE being as close to the service equipment as possible and exiting the concrete in the form of #4 bare,solid,copper is in no need of extending. Then the word is all you need is #4.

If the turn up method is nationally supported, then the NEC should reflect it in the "words". Still I like the way you think!

frank

 

[tomgreen1000]

Re: Concrete Encased Electrode

what if the slab is existing, do you chip out some concrete and expose the reinforcing steel, so as to bond to it?

Depends on the inspector I think. We have had to open the concrete and expose the existing steel on several DSA jobs (California Department of State Architect - all school jobs in CA). Most DSA inspectors do not require this, but a few do.

Looking forward to the exception in 2005 code, but as Physis noted, I could be retired before it is adopted in CA (still on 99 in my location)

Tom

[ July 21, 2005, 08:09 PM: Message edited by: tomgreen1000 ]

 

[infinity]

Re: Concrete Encased Electrode

So,the CEE being as close to the service equipment as possible and exiting the concrete in the form of #4 bare,solid,copper is in no need of extending.

Is it required to be bare and solid?

 

[physis]

Re: Concrete Encased Electrode

Solid? Does it say that?

Can I ask you guys a favor? I don't have 2005 and this code change always looks like a mystery novel to me.

Can someone post the 2005 change for me?

 

[benaround]

Re: Concrete Encased Electrode

250.62 the conductor shall be solid or stranded,insulated,covered,or bare.

I don't see a problem with bare,solid,copper?

frank

 

[macmikeman]

Re: Concrete Encased Electrode

In my area there isn't usually very much of a footing, at least not like most of you guy's get. Our slabs usually are turn down at the edges about 12". Is this turn down area steel rebar good enough to be effective as a grounding electrode ?

 

[George Stolz]

Re: Concrete Encased Electrode

Originally posted by physis:
Solid? Does it say that?

Can I ask you guys a favor? I don't have 2005 and this code change always looks like a mystery novel to me.

Can someone post the 2005 change for me?

250.50 GES. All grounding electrodes as described in 250.52(A)(1)...yada yada, no real change after that. Then it says:

Exception: Concrete-encased electrodes of existing buildings or structures shall not be required to be part of the grounding electrode system where the steel reinforcing bars or rods are not accessible for use without disturbing the concrete.

So,the CEE being as close to the service equipment as possible and exiting the concrete in the form of #4 bare,solid,copper is in no need of extending.

Is it required to be bare and solid?

250.62 the conductor shall be solid or stranded,insulated,covered,or bare.

I don't see a problem with bare,solid,copper?

I think what they're getting at is, it isn't required to bare or solid.

The catch is, where do you buy stranded bare copper? The second catch is, if it's insulated, it's not going to make a connection with the concrete.

I smell a proposal lurking around here.

 

[don_resqcapt19]

Re: Concrete Encased Electrode

The second catch is, if it's insulated, it's not going to make a connection with the concrete.

This section, 250.62, is talking about the GEC. There is no requirement that the GEC have a connection to the concrete.
Don

 

[derf48]

Re: Concrete Encased Electrode

The change in 250.50 is a simple one. The word available was changed to present, so now it reads "All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are PRESENT at each building..." The exception is as written by George earlier.

By changing the word available to present, the CMP is trying to make the ufer ground a requirement.

Fred

 

[physis]

Re: Concrete Encased Electrode

That's what I thought. I still don't understand all the confusion.

Thanks you guys.