Ground Conductor Splicing

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gndrod

Senior Member
Location
Ca and Wa
Re: Ground Conductor Splicing

Bob, As an experienced electrician, I can suck that one up if the truth hurts, but as far as helping someone get an answer I have no regrets.
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Re: Ground Conductor Splicing

RBJ, we've had a very stressful discussion here, I feel it would take very little for everybody to throw their hands up, grab their toys and go home, and I in no way wish for that to happen. Please do not antagonize Bob any further.

We're all friends discussing a badly written book here. Anything Bob has said that might be read as demeaning to me, or whatever, is the product of a well-founded frustration over a discussion. Bob and I see eye-to-eye on most subjects, and this is an uncommon exception. That is a recipe for "What the heck are you smoking, George?" I understand and accept that, I would react just the same way. :)

Thank you for sticking up for me, and for your very snazzy load calc sheets, I just saw those tonight. Very cool, and very marketable, I think. I think AHJ's might be more interested in them than electricians, especially with the carbonless copy idea. :)

Now hug and make up. :D
 

gndrod

Senior Member
Location
Ca and Wa
Re: Ground Conductor Splicing

Okay Bob, Please accept my apologies for being so irascible. Tx George.

[ December 13, 2005, 10:58 PM: Message edited by: gndrod ]
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: Ground Conductor Splicing

Originally posted by iwire: I can not agree about the concrete encased electrode.
Just in case it might make a difference, may I invite to your attention that 250.52(A)(3) does not provide the definition of "concrete encased electrode"? It does not tell us what is, and what is not, a "concrete encased electrode." It does not tell us where a "concrete encased electrode" begins, and where it ends.

To see what I mean, and why I chose to agree with George's point of view, you have to look at sentence structure. You may start by noting that the first sentence of that article is not a complete English sentence, in that it contains no verb. There are three phrases that contain verb-like words ("is" appears in one and "consisting" appears in two), but the sentence as a whole does not have a verb. So we must find the "understood" verb, and from that, you infer the intended meaning of the sentence.

To do that, look at the paragraph titles. The title to 250.52 is just a title; so is the title to 250.52(A)(3). Neither comes into play within the sentence in which I am interested. The title to 250.52(A) does come into play. Here is how I would construct a sentence out of the non-sentence that begins 250.52(A)(3):
Electrodes permitted for grounding INCLUDE an electrode encased by at least 2 inches of concrete . . . .
That tells me that I can bury a wire in concrete and I can use it as a component of the GES. It does not tell me where the "electrode" part of this "concrete encased electrode" begins or ends.

On the other hand, there is a definition for "grounding electrode," as I said earlier.
Originally posted by iwire: So be it, I may put in a proposal on this one.
You better hurry! You only have two years and ten months or so to get it in. :D
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: Ground Conductor Splicing

Originally posted by georgestolz: Standing dead cold and looking this directly in the eye, I would state that your statement is entirely correct.

However, using the reasoning that the "shall not" statement is what gives us permission leaves a large hole in the discussion, which gives Bob an ample berth to rest on. There is no similar restriction on the Ufer.
There doesn't have to be. There is no rule that says every article in the NEC must be written the same way as every other article.

Please note that there is a really good reason for prohibiting connecting to a water pipe too far away from the point of entrance. I mentioned it earlier. That is why there is a "shall not" statement in the rule about water pipes. If there is no similar reason to prohibit connecting a given distance away from any particular point in a UFER, then they don't have to include a "shall not" statement.
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Ground Conductor Splicing

Originally posted by charlie b:
Just in case it might make a difference, may I invite to your attention that 250.52(A)(3) does not provide the definition of "concrete encased electrode"? It does not tell us what is, and what is not, a "concrete encased electrode." It does not tell us where a "concrete encased electrode" begins, and where it ends.
It might as that is my whole argument.

IMO 250.52(A)(3) tells us exactly where it ends.

If it does not end where I think it does where would you or george say it ends?

How far can I 'stub out' the rebar before I must connect to it?

Can I stub out and run a 100' across the building to the service by tying steel rebar together?

Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.
What would the support and physical protection requirements be for this string of rebar?

Originally posted by charlie b:
You better hurry! You only have two years and ten months or so to get it in. :D
:D

And only about 5 years till I might see a change. :D
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: Ground Conductor Splicing

Originally posted by iwire: IMO 250.52(A)(3) tells us exactly where it ends.
IMO, it doesn't. If you have 20 feet of #4 in concrete, you have an electrode. But where it begins or ends is not mentioned in that paragraph. All the paragraph says is that you can connect to an electrode that consists of 20 feet of #4 encased in concrete. If you have 40 feet of #4 encased in concrete, it is still an electrode. If you have 22 feet of #4 with the last 2 feet sticking up out of the concrete, you still have an electrode. The code does not say that the electrode ends when the concrete ends. You are drawing that inference, but the words are not there.
Originally posted by iwire: If it does not end where I think it does, where would you or George say it ends?
I think the electrode certainly ends at the point you connect a GEC to it. I know that does not really answer your question. But using that reasoning, I would say that if you tie one rebar to another outside the concrete encasement, then the extra rebar is not part of the electrode.

But how far should the last section of rebar be allowed to stub up, before you connect a wire to it? Similarly, how far should the #4 wire be allowed to stub up, before you connect a wire to it? The NEC does not give us either answer. If I were the Inspector (be afraid, be very afraid :D ).
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Ground Conductor Splicing

No offense meant Charlie but that last post did not make me have a change a of heart.

You seem to have moved from code to personal preferences.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: Ground Conductor Splicing

Originally posted by iwire:You seem to have moved from code to personal preferences.
No. I never had a clear code statement to draw upon. It has always been a personal interpretation of the intent of the code. But that goes for you as well, I think.

I had no intention of inducing you to change your mind. I merely explained my view and the basis of my view, and let you do with it as you wish.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Re: Ground Conductor Splicing

Originally posted by charlie b:
I would allow 2 feet of wire, but would not allow 12 feet.
Could we infer from that statement that, even if the 12 feet of #4 could reach the proper termination point, you would want it to be cut near the emergence of the concrete, and then have another section of #4 irreversibly connected to it, since the electrode can't be its own GEC?
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Re: Ground Conductor Splicing

Originally posted by charlie b:
Originally posted by iwire: If it does not end where I think it does, where would you or George say it ends?
I think the electrode certainly ends at the point you connect a GEC to it.
I can't agree with this statement. Perhaps I'm misunderstanding what you're saying.

IMO, the electrode continues until it doesn't resemble an electrode anymore. Otherwise interconnecting electrodes would be impossible: because as soon as a GEC was connected, you'd be outside of the electrode when you came along with the next conductor.

IMO:
</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">In the case of a water pipe, it is an electrode until it switches to PVC, or ends in a sink. (If this were not the case, we wouldn't need to be prohibited from attaching near the sink.)</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">In the case of structural metal, it ends at the ends of the structure.</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">In the case of a Ufer, it ends at the end of the #4 or rebar.</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">In the case of a ground ring, it ends...it uh...well it ends...is this a polish joke?</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">In the case of a rod, it ends at the end of the rod.</font>
  • <font size="2" face="Verdana, Helvetica, sans-serif">In the case of a plate, it ends at the end of the plate.</font>
<font size="2" face="Verdana, Helvetica, sans-serif">
I'm opening this up a tad, because of this statement:

How far can I 'stub out' the rebar before I must connect to it?
Can I stub out and run a 100' across the building to the service by tying steel rebar together?

Reinforcing bars shall be permitted to be bonded together by the usual steel tie wires or other effective means.
What would the support and physical protection requirements be for this string of rebar?
Here in the real world, we can surmise that the steel tie wires are a temporary fastening means to secure rebar together until such a time that the concrete is poured, and the concrete creates the permanent structural bond for the rebar (for our purposes).

For the purposes of the NEC, I believe they are clarifying that the surface contact of rebar pressing against rebar, brought about by lashing pieces of rebar together, is sufficient. Using clamps and conductors to connect the different pieces of rebar is not necessary.

With that in mind, lashing pieces of rebar together with steel tie wires would not be very permanent outside of the concrete.

250.68(B) Effective Grounding Path. The connection of a grounding electrode conductor or bonding jumper to a grounding electrode shall be made in a manner that will ensure a permanent and effective grounding path.
While this is talking about the actual connection of the GEC to the electrode, I think it stands to reason that if that connection must be permanent and effective, then so should the electrode it's hooked to.

A solid piece of rebar, or a solid piece of #4, is not going to disintegrate in short order. A metallic water pipe is not going to disintegrate. The top of a ground rod isn't going to disintegrate. The, uh...well the ground ring's fine too. :D
 

iwire

Moderator
Staff member
Location
Massachusetts
Re: Ground Conductor Splicing

George you guessing and stretching. :D

Either the electrode stops inside the concrete encasement or I can lash rods together as far as I want.

It is the only way the rest of the requirements work. :p
 

George Stolz

Moderator
Staff member
Location
Windsor, CO NEC: 2017
Occupation
Service Manager
Re: Ground Conductor Splicing

One more thing: the water pipe was not "holding together" by virtue of the fact that people kept hacking it in half and putting plastic in. So they wrote a rule to overcome that.

They wrote a rule to restrict how we operate outside the defined area of that electrode.

I'll betcha if people start lashing rebar together and it keeps falling apart, they'll write similar language to the water pipe's 5' rule.

Boy, then you'll feel silly for doubting me. :D :D :D
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
Re: Ground Conductor Splicing

Originally posted by LarryFine: Could we infer from that statement that . . .?
You are free to infer what you wish, but that is not what I implied. It was a not-all-that-serious statement whose purpose was to emphasize the absence of any clear instructions from the authors of the NEC.

I do not know, as I said earlier, whether it is allowable by code to have a single length of conductor, one end of which is encased in concrete, and the other end of which is connected at the service entrance. You would look at the one end, and say "This is an electrode." You would look at the other end, and say "This is a GEC." So, does it change its identity somewhere in the middle, or is it an "electrode" for its entire length, or is it a "GEC" for its entire length? The code does not say. That is why there is a debate here, and that is why I see no way for the debate to end with a clear winner. That is also why I think I will drop out of this discussion, at least for the present.
 

A/A Fuel GTX

Senior Member
Location
WI & AZ
Occupation
Electrician
Re: Ground Conductor Splicing

Isn't the actual theory of the " Ufer " the fact that concrete never fully cures to the point that there is no moisture and therefore is a good conductor to earth. Ufers have been used for years and at one time, the re bar wasn't even part of the requirement rather just a vehicle to attach the 20' of bare #4 copper to. So the way the code reads today, I would say that the re bar is the electrode and the #4 is the GEC.
 
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