Concrete Encased Electrode

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dsteves said:
Now, everybody get out your books and turn to 250.52(A)(3).
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Dan it's just my personal opinion but I do not like being 'spoken to' as if I am an idiot.

Many people here are very aware of the rules in the NEC, it is by no means a DIY site.

JMO, Bob
 
I've gotta learn to type faster or type less. That took an hour!

Maybe the less part is in order, Bob. A little less wording might have taken off the sardonic edge. You are quite right; that is one of my character flaws. My humor is a little dry for some. Don't take anything I said personally.

Perhaps a brief explanation of my position is in order. I have a colleague who is currently overseeing the construction of a ~200,000 ft^2 building. The EC is showing 8' rod in ground around the building with a ground ring, but they thought I was nuts when I told them they needed to use the footing rebar in the system. The last grounding drawing details building steel to ring, but no 250.52(A)(3) compliance. So when I see debate on the matter here, I am challenging myself to make a logical argument sufficiently explanatory for universal comprehension. Not possible, true. But I've gots ta try. I realize that there is a wide spectrum of knowledge and experience represented on this site. I am not trying to insult, but rather to clarify beyond doubt.

Dan
 
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iwire said:
Morning Roger, sorry if I answered your post
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Don't worry about that Bob, I know I have answered some of yours in the past.

Roger
 
Dan, that was a long humdinger of a post. I've written some long ones, but I think that took the cake.

The humor of it took off some of the negative tone, for me. :)

However, there is a deficiency in your reasoning:
dsteves said:
I also submit that in new construction (which includes modifying old construction, ladies and gentlemen)...
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The section you dissected refers to existing structures. That is the term used. The structure is existing. We are adding a new part to an existing structure.

If they pour the footer before I show up to an existing structure, I would not need to worry about it, regardless of what drama went down before I showed up.
 
Good morning, George. Yes, there's some wiggle room on the existing construction. I suppose it could go either way. My interpretation is that you are not required to disturb existing work to connect, but if you voluntarily expose the CEE, things change.

I still see no exception on an addition to an existing building. The new CEE is covered by (A)(3). The GC needs to coordinate. The EC should ask the question and inform the GC of the need to coordinate if the CEE will be installed. It might be too late, though, because the GC might not think it important to involve an EC until the flatwork is done. Alas, back to square one. What does a jackhammer sound like in a basement?


Never write a post until you've had (2) cups of morning fluid.

Dan
 
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dsteves said:
Never write a post until you've had (2) cups of morning fluid.
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No kidding. I ran out yesterday, didn't make it to the store.
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If you miss it you would have to do a lot of jackhammering. :D

Simply exposing a section of rebar and connecting to it is not enough.

You would have to verify the rebar meets all the requirements and is located in the bottom of the footing, not the foundation or slab. ;)
 
My mentor of the last 20 years is a retired PE here. He bought his wife a laptop computer and asked me to configure it for her for internet access. I've been using it to post here yesterday and today; therefore I believe I can report that is internet-ready. I hope I didn't damage any of the keys...


Off for delivery. Have a good day, folks.

In the mean time, iwire, could you verify that rod for me? ;-)

Dan
 
dsteves said:
In the mean time, iwire, could you verify that rod for me?
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Sure, would you like the three point fall of potential test or would a clamp on meter be acceptable. ;)

Here in my area any equipment required by the NEC is subject to inspection.

I must call for an inspection before the pour so that the electrical inspector can see the installation.

If I do not get signed of on a CCC it will be a major issue later.
 
Dan, is it safe to summarize your position by saying: "If there is construction to an existing building which presents an additional electrode as defined by 250.52, then this electrode must be bonded to the existing grounding electrode system." ?

John
 
Based on a rather speedy skim of 8 pages I have me a question now. If I am installing a new seperatly derived system to a new addition to an existing building do I run my new gec to "new" building steel or do I have to land it on "old" building steel?. In theory should the new construction have to disrupt the "old" building rebar to start the ball rolling for an "existing" service , or is installing "new" rebar in the new footing the requirement to go back and re-invent the service grounding for the existing building? Does this make any sense? Wait, that was three questions.
 
j_erickson said:
Dan, is it safe to summarize your position by saying: "If there is construction to an existing building which presents an additional electrode as defined by 250.52, then this electrode must be bonded to the existing grounding electrode system." ?

John
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Good morning, John. Yes, that's my position. I wish I could have said it so eloquently myself :) Long and short on my position is that it is not likely you have too many elements in a GES. Hope you all enjoyed the weekend.

Dan
 
macmikeman said:
Based on a rather speedy skim of 8 pages I have me a question now. If I am installing a new seperatly derived system to a new addition to an existing building do I run my new gec to "new" building steel or do I have to land it on "old" building steel?. In theory should the new construction have to disrupt the "old" building rebar to start the ball rolling for an "existing" service , or is installing "new" rebar in the new footing the requirement to go back and re-invent the service grounding for the existing building? Does this make any sense? Wait, that was three questions.
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The purpose of the GES is, among other things, to establish an equipotential plane within the building(s) and/or structure(s) being served. If you take a lightning strike on any part, you want all parts to swing together during the event. If you don't have the "new" and "old" GES's effectively bonded, then you will have a significant voltage between the two GES's during the lightning strike. Anything caught in between will not fare well.

I attended a grounding class about 10 years ago, wherein the instructor used an example of a hotel in Chicago that updated its phone system to a PBX. The installers decided to establish a GES around the new phone closet. They did not bond the new GES to the old GES. Lightning hit the service and blew up the phone system. I'm not sure that helps.

I'm on my second cup of coffee, so I think I'm less cranky today. Hard telling not knowing.

Dan
 
dsteves said:
Good morning, John. Yes, that's my position. I wish I could have said it so eloquently myself :) Long and short on my position is that it is not likely you have too many elements in a GES. Hope you all enjoyed the weekend.

Dan
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Thanks, Dan.

Can't speak for others, but I had a great weekend. Hope you did as well.

John
 
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