Concrete Encased Electrode

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j_erickson said:
Steve,

I don't have my book with me, but I've read that article many times. It was revised by changing the phrase from "if available" to "if present" with regards to the CEE. Meaning if there is rebar, you must use it. It does not mean that you must install 20' of wire if there is not rebar present. Essentially the 20' of copper wire is not present, unless you put it there, in which case you must use it.
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John I agree. We got off on the "if available" tangent. As I stated the earth is "available" to accept ground rods. That doesn't mean that I have to install any. As I said back in my first post, no rebar-no CEE required.
 
Steve, if you're interested, here is one of the comments that pushed this section to change. The problem was, everybody was showing up to rough a house once it was framed, dried in, sided, plumbed, etc, and saying "lo and behold! There is no CEE available!"

The section was changed to clarify, "Hey, tough guy, it was available a month ago. You should have used it. And from now on, you will."

Nothing more, nothing less. :)

Code: 
5-81 Log #1365 NEC-P05 Final Action: Accept in Principle
( 250.50 Exception )
________________________________________________________________
Submitter: Andre R. Cartal, Princeton Borough Building Dept.
Comment on Proposal No: 5-115
Recommendation: The Panel should accept this proposal with the following
Exception:
Exception: Concrete-encased electrodes in footings of existing buildings shall
not be required to be part of the grounding electrode system.
Substantiation: The words ?if available? has prevented the use of a proven
grounding electrode for too many years. These words have no place in the
NEC. From the inspectorʼs viewpoint, it presents a no-win enforcement problem.
The removal of these words will require electrical design professionals to
specify and also enforce compliance with 250.50.
Panel Meeting Action: Accept in Principle
Revise 250.50 to read as follows:
?250.50 Grounding Electrode System.
All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are
present at each building or structure served shall be bonded together to form
the grounding electrode system. Where none of these grounding electrodes
exist, one or more of the grounding electrodes specified in 250.52(A)(4)
through (A)(7) shall be installed and used.
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.?
Panel Statement: Implementation of requirements proposed in 5-115 is not
feasible for all installations. An exception is needed to prevent situations
where concrete would be required to be disturbed. Additional editorial changes
were made to improve clarity.
Number Eligible to Vote: 16
Ballot Results: Affirmative: 16
Comment on Affirmative:
ROBERTSON: I am voting in the affirmative, however, I would like to make
a comment on this one.
I agree with the substantiation that the words ?if available? have prevented
the use of a proven electrode for too many years. By removing the words ?if
available? and replacing with the proposed text will now mean the Authority
Having Jurisdiction will need to be aware of the sequence of construction and
the reality that in a lot of cases the concrete encased electrode is, in fact, not
available by the time the decision is made on which electrical contractor will
be doing the project.
It will now become the responsibility of the Authority Having Jurisdiction
to make sure these electrodes are made available for use prior to the concrete
being poured in the foundations.
On far too many projects the foundations, spread beams, piers and grade
beams are poured prior to awarding the electrical work on a project.
This concern should not be a factor in making the change, it will however,
require some changes in the timing of when electrical contracts are awarded in
some areas.
Electrical contractors will need to keep this in mind when accepting projects.
 
Well, thanks for the effort. Like I said, San Diego County seems to share my opinion. They have issued an interpretation that UFERs are mandatory in new construction so I have no choice.

See page 16 http://www.iccsandiego.org/uploads/2005 Electrical Newsletter Final 1-10-06.pdf

It seems clear to me that the intent was to use UFERs whenever possible since they are so effective. If adding #4 CU to the foundation was optional it would have been a FPN or the words "may" be used would appear.

I've enjoyed the discussion. I will research the subject offline.
 
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After reviewing all this, does anybody disagree with the following? I'm wiring a new addition to a home. The service is not being upgraded. The addition contains at least 20' of #4 rebar. I am not required to connect a grounding electrode conductor to the rebar. Not saying it isn't a good idea, I just want to confirm I don't have to connect.
 
mkgrady said:
After reviewing all this, does anybody disagree with the following? I'm wiring a new addition to a home. The service is not being upgraded. The addition contains at least 20' of #4 rebar. I am not required to connect a grounding electrode conductor to the rebar. Not saying it isn't a good idea, I just want to confirm I don't have to connect.
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I agree that you do not need to use the newly available CEE on your existing service.
 
CEE bonding

CEE bonding

250.50 Exception only covers existing buildings in which the CEE is not accessible without jackhammering. If you are adding on to the building, there is no exception. You MUST use the CEE if its dimensions meet or exceed the specifications in 250.52(A)(3).


Git 'r dun before the cement head completely covers them up.

Dan
 
dsteves said:
250.50 Exception only covers existing buildings in which the CEE is not accessible without jackhammering. If you are adding on to the building, there is no exception. You MUST use the CEE if its dimensions meet or exceed the specifications in 250.52(A)(3).


Git 'r dun before the cement head completely covers them up.

Dan
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Not if you are not touching the service
 
dsteves said:
250.50 Exception only covers existing buildings in which the CEE is not accessible without jackhammering. If you are adding on to the building, there is no exception. You MUST use the CEE if its dimensions meet or exceed the specifications in 250.52(A)(3).


Git 'r dun before the cement head completely covers them up.

Dan
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The NEC is unclear on this. It would be up to the AHJ to decide if it's required. Around here a simple addition does not mean that you must bring the entire structure up to code. Portions of the existing structure that are untouched can remain as is since they would be grandfathered in. IMO if you're not touching the service than adding the CEE is not required.
 
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j_erickson said:
Not if you are not touching the service
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I'm sorry, I don't see where the exception applies. 250.50 is a short paragraph. Could you quote the paragraph where adding elements to a GES are exempt if you're not upgrading the service? If he's putting on an addition, the Code requires new work to comply with the current Code. The Code isn't making him go back and tie in the old work. Of course, the old work doesn't have to be changed, unless you are modifying the old work. The CEE is a non-issue in old work, and the Code writers understand that. The 2005 code language in 250.50 was specifically changed to explain that if it's there it must be used. The clarification was intended for the benefit of the AHJ. IAEI wrote a pretty good article on the matter in the October 2005 on-line magazine.

1424 cdt - The requirement has nothing to do with the service. It has everything to do with the building or structure being serviced, and the establishment of an effective grounding electrode system.

Let's say he drives a 5/8" copper rod 10' into the earth next to the addition. Would he have to tie it into the GES if it's there? Yes, he would. But assuming he has not driven the rod and has met the minimum requirements of 250.52, he wouldn't have to drive a rod. One could argue successfully that the rod doesn't have to be bonded if not present. Yep, that's a fact. Pull the rod out and you don't need to bond it.

Likewise, if there is no CEE, the Code does not require its installation. The Code is also specific that the CEE is in a foundation or footing in direct contact with the earth, meaning no vapor barrier, exempli gratis. There is no mention of CEE in concrete flooring. Now, if the folks putting in the footings and/or foundation elect to use reinforcing rods of #4 or larger, with 20 or more feet of total rod length, they're in there and you must use them in your GES. If they choose not to use rebar for some reason, and local building codes don't require them, you're off the hook. No CEE, no bond.

[edited 1403 cdt] If the CEE is not not copper, it must be no less than 1/2" in diameter. If it is copper, it is permitted to be not smaller than 4AWG. Any GEC not meeting this diameter requirement does not meet the requirement of 250.52(a)(3) and is not required to be connected to the GES. So, 3/8" (#3) or smaller rebar wouldn't be required to be bonded to the GES.


Dan
 
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Now I'm thinking the CEE must get connected because it is currently being installed, it is accessable, and I will not have to disturb the concrete to connect to it.

I think the exception to 250.50 could have been stated more clearly. My first read told me that existing buildings are exempt from connecting to a CEE but it now seems that new additions to existing buildings are not exempt.

It is going to be a real chore to connect the CEE to the existing GES. I'm glad the job is T&M. Can I connect to any part of the GES or does it have to go back to the service?
 
Look at it this way, if the original structure had a well with plastic pipe coming into the house and then they got hooked up to a town water system and was fed into the house with a copper line would this be required to become part of the service electrode system, I would say yes making it no different then the CEE.
 
Boy, am I glad I do not do residential old work for a living. If I were to take a job to install a new receptacle in a house built in 1951, then I would need to be sure to include GFI protecting the receptacles and spacing in their kitchen, installing GEC's, EGC's, and repairing any DIY work not done to code over the past fifty years.

Better get out a shovel and verify that there's not a ground ring or plate buried in the yard! :D

That's a hard-earned $150!

The NEC is not retroactive. If all the electrodes available when the service was built were utilized, then the service is complete.

The local AHJ in your area may have a different stance on it. It should be in writing.
 
mkgrady said:
Now I'm thinking the CEE must get connected because it is currently being installed, it is accessable, and I will not have to disturb the concrete to connect to it.

I think the exception to 250.50 could have been stated more clearly. My first read told me that existing buildings are exempt from connecting to a CEE but it now seems that new additions to existing buildings are not exempt.

It is going to be a real chore to connect the CEE to the existing GES. I'm glad the job is T&M. Can I connect to any part of the GES or does it have to go back to the service?
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Correct. It is new, therefore it must comply. Forget the accessible part, though. That's part of the wording change (deleted) in the 2005 Code. You need to coordinate with whoever pours the concrete to get on it before it's covered up, or chisel to it later. George, you are also right, *but* as soon as you *ADD* a concrete-encased electrode in *new* construction (whether it's next to *old* construction or not), the *new* construction must comply with the Code in effect during the construction. [Hint: get your 2007 work done before January 1, 2008 :) ]

See 250.66 for sizing the GEC. The GEC from the CEE must be effectively bonded to the rest of the GES. My interpretation of this is that you are permitted to run a GEC with the phase and neutral conductors to your new subpanel, provide a ground bar in the new panel, and tie the GEC from the CEE to the GEC from the original service there. Of course, no green screw goes in the remote box. The conductor from the CEE to the bond point is not required to be larger than #4 AWG, according to 250.66(B). The GEC from the main service panel to the remote load center should be sized according to the size of the SE conductors.

Oops, I didn't address the last question. My bad. The answer is, if the existing GEC is properly sized for the existing service, you can connect to it anywhere, as long as you use an approved method of making the connection. Connectors listed for the purpose are a good call (read:required). 250.70 explains the connection at the CEE.


Dan
 
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Dan,
dsteves said:
George, you are also right, *but* as soon as you *ADD* a concrete-encased electrode in *new* construction (whether it's next to *old* construction or not), the *new* construction must comply with the Code in effect during the construction.
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That is correct. You must attach the new CEE to the new service you're installing on the new addition. :D

If there isn't a new service, what is the mechanism forcing you to upgrade an old service?

I'm being playful, not spiteful, I hope you understand that. :)

I think the discussion is kind of never ending, since the AHJ has the ultimate call.
 
George, I don't think it affects the service retroactively. It isn't the service that's being tweaked here. It's the building or structure being supplied.

I guess I'd use a set of examples to illustrate the point. Let's say you decide you need a dedicated receptacle in your living room for your entertainment center. The living room is in your 60 year old home, which has not been electrically modified since it was built. You don't have any grounding receptacles anywhere in the house yet. The entertainment center will be the first circuit in the house with a grounding pin.

The Code doesn't require you to do anything at all with any other wiring in the house, but you are required to run a grounding conductor from the new receptacle to your GES. Even if you chose to simply replace an old two-wire receptacle on the end of an existing circuit with a three-wire recep, you aren't required to go back upstream and replace all of the wiring and receps in the circuit. All you have to do is get the grounding conductor from the new receptacle back to the GES. This is in accordance with 250.130(C).

You're modifying the existing wiring, but you aren't doing anything with the service. You don't have to touch the service or its GES.

Now, on the other hand, let's say you have damage on your concrete block basement wall due to frost, and you pay a contractor to fix it. He excavates the soil etc. from the wall exterior, shores up the house, puts in a new footing with 35' of #5 bar in it, forms up a poured wall, pours it, caps it and puts the house back down on the new wall. The CEE is new, so you'd have to connect it to your GES. That's all, though. You still aren't doing anything with the service. Article 230 addresses services. Article 250 addresses grounding and bonding.

Another example - let's say you decided you're going to upgrade the 60-amp service in your 60-year-old house to 100 amp service. You are not required anywhere in article 230 to add a CEE if it doesn't already exist, but you may have to upsize your GEC according to 250.66 if it isn't already of sufficient size. Now, a 100 amp service could be fed with #3 THHN, so you'd only need #8 CU for the GEC. Maybe the old GEC was #10. In that case you'd have to replace it when you upsized your service. If the old GEC was #8, you could leave it alone.

The point I'm trying to illustrate is that grounding and bonding requirements for new construction don't imply a modification to the service - they only involve the grounding system. On the other hand, changes to the service will usually have an effect on the requirements of the grounding system, unless you're downsizing your service (not typical, I'd say...).


If I sound cocky or argumentative, I apologize. That's not the point of the exercise. I'm always trying to expand my knowledge, and in the rare instance where I think I can shed some light on a subject I'm not characteristically shy about sharing it.

Dan

PS - The AHJ agent is without doubt the wildcard. Typically the agent isn't exactly a pundit of electrical knowledge, either. The full-time job could involve asking whether you want fries with that.
 
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My interpretation of this is that you are permitted to run a GEC with the phase and neutral conductors to your new subpanel, provide a ground bar in the new panel, and tie the GEC from the CEE to the GEC from the original service there. Of course, no green screw goes in the remote box.
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Nowhere does it say that if you are "splicing" a gec using one of the exceptions that a busbar used for splicing must be mounted in a panel. You could mount it anywhere not subject to physical damage.
 
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macmikeman said:
Nowhere does it say that if you are "splicing" a gec using one of the exceptions that a busbar used for splicing must be mounted in a panel. You could mount it anywhere not subject to physical damage.
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Truer words were never spoken. I suggested doing it that way since he's already putting in a subpanel, so it seemed like a logical choice.

Touche'

Dan
 
Dan,

I think you've convinced me. But to be clear, the CEE needs to be part of the GES. However in the OP, if the GEC were inadequate, it would not be required to be addressed. The new CEE could be bonded to an existing ground rod, for example. Would you agree?
 
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