250.50 again

[mayjong]

i know this has been pounded.
if i have a footing, and in that footing is 20' of 1/2" rebar, and there also happens to be a 20' long piece of #4 copper in the footing , aren't they BOTH REQUIRED to be bonded?
are the grounding electrodes described in 250.52(A)(1) through 250.52(A)(6)
actually grounding electrodes if they are not attached to the GEC?

if they are not attached to the GEC are they still "present" ???

if they are not "present" then they don't have to be used, correct???
what about the exception that calls the reinforcement in an existing foundation a "concrete encased electrode"? how can it be an electrode if it is not connected to a GEC?

i thought i understood.... now i am confused again! help!

 

[don_resqcapt19]

I don't see any need for a pole on this issue...the code is very clear. If any of the items listed in 250.52(A)(1) through (A)(6) physically exist at the building, they must be used as part of the grounding electrode system.
Don

 

[iwire]

If they are present you must connect to them.

If you drive a ground rod in the ground it is present regardless of it being connected or not.

But because it is present you must connect to it.

 

[ryan_618]

A change to the 2008 will clairfy that if there are multiple concrete encased electrodes present, only one is required to be connected to.

 

[mayjong]

thanks for humoring me- this is the argument i'm getting------
2005 NEC; Definitions,

"Grounding Electrode. A device that establishes an electrical connection the earth."

"Grounding Electrode Conductor. The conductor used to connect the grounding electrode(s) to the equipment grounding conductor, to the grounded conductor, or to both."

If you do not connect the objects, whether rebar, rod in ground, or any other object "that may be used" but are not used (connected) to the equipment grounding conductor, to the grounded conductor, or to both; they are not grounding electrodes."-----

seems this person is trying very hard to not use all the GE's "present" ...

 

[infinity]

If you do not connect an electrode that is present it still "is present". His argument is very weak.

 

[mayjong]

agreed-
his point is the definition of grounding electrode "a device that establishes an electrical connection the earth."
his point is if it (the grounding electrode) is not establishing an electrical connection to earth (is not connected to the GEC) then it (the GE) is not "present" (because it doesn't meet the definition)

sounds like double (and triple)speak to me!!!
like i said, he seems to be trying very hard to NOT use all the GE's present.

 

[gndrod]

agreed-
his point is the definition of grounding electrode "a device that establishes an electrical connection the earth."
his point is if it (the grounding electrode) is not establishing an electrical connection to earth (is not connected to the GEC) then it (the GE) is not "present" (because it doesn't meet the definition)

sounds like double (and triple)speak to me!!!
like i said, he seems to be trying very hard to NOT use all the GE's present.

[250.53] Grounding electrode system includes "where practicable" (a GWB linguistic invention) for rod, pipe, plate, shall be embedded....etc., surely invites confusion between common and tap grounding electrodes. Two or more bonded grounding electrodes comprise the single grounding electrode system "in this sense". (NEC quote) Interpret that any way you want until the AHJ sees a metal pipe of substantial size and deems that as to be bonded and can be the gotcha.

Common electrodes are termed "as available" and tap electrodes as "if present". FWIW, not establishing an electrical ground connection to earth of any [250.52] metal around a structure is out of the question and after looking at [250.58] that may really be hard to avoid regardless of which metal is deemed not a GEC connected part. rbj

 

[gndrod]

A change to the 2008 will clairfy that if there are multiple concrete encased electrodes present, only one is required to be connected to.

I agree with ryan. That would also include if a 20' x #4 AWG copper UFER was installed prior to foundation pour. At that point the AHJ would see the rebar forms as needing connection to the AWG to conform to 250.50 "are present".