An Inspector's take on CEE use

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wbalsam1

wbalsam1

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Upper Jay, NY
In New York State, 1 & 2 Family dwellings and Townhouses are regulated by the Residential Code of NYS (RCNYS) which is based on the 2002 NEC. 250.50 says "If available".
When the change came along in '05, the phrasing was "where present". All buildings other than those subject to the 2002 NEC are required to be wired in accordance with the '05 NEC.
The term "where present" (changed from 'if available') was intended to clarify and offer guidance as to which electrodes are required to form the grounding electrode system. CEE's are generally "present", because they are considered an inherent part of the building/structure.
So to recap, in the '02, if the CEE's are made available, they may (permissive language) be used; in the '05, where present, they shall (mandatory) be used. :smile:
 
Same here in MA when we went to the 2005 on 1/1/05.

Here is what the State had to say to GCs in 2004. :)

CEE_Page_1.jpg



CEE_Page_2.jpg
 
wbalsam1 said:
So to recap, in the '02, if the CEE's are made available, they may (permissive language) be used; in the '05, where present, they shall (mandatory) be used. :smile:
Click to expand...

Unfortunately not everyone thinks that is so. At our last NC association of EC's meeting we had about 20 members there and I was the only one that takes advantage of the CEE. A few inspectors where there and they said the wording is still ambiguous since it is not available when the EC arrives. Doh.

I don't get it- one would think you would want to install a safer system then the ground rods. IMO it is a better system. I need to measure the ohms someday and see what the difference actually is.
 
wbalsam1 said:
In New York State, 1 & 2 Family dwellings and Townhouses are regulated by the Residential Code of NYS (RCNYS) which is based on the 2002 NEC. 250.50 says "If available".
When the change came along in '05, the phrasing was "where present". All buildings other than those subject to the 2002 NEC are required to be wired in accordance with the '05 NEC.
The term "where present" (changed from 'if available') was intended to clarify and offer guidance as to which electrodes are required to form the grounding electrode system. CEE's are generally "present", because they are considered an inherent part of the building/structure.
So to recap, in the '02, if the CEE's are made available, they may (permissive language) be used; in the '05, where present, they shall (mandatory) be used. :smile:
Click to expand...


Fred
I concur...:wink:
 
Dennis Alwon said:
Gee whiz-- you will have to exp;ain that to me since I don't even know what a variac is. :smile:
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It's a variable auto-transformer. Here's a modern one:

variac_sweetmarias.jpg


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LarryFine said:
It's a variable auto-transformer. Here's a modern one:
Click to expand...

Well I was smart enough to look on the internet and find a picture but how is this used to test the ohms on a cee vs a ground rod?

I believe your original response was to my ohms question.
 
IMO you really could not use it to get a good answer.

In theory if you hooked one side of the variac output to the electrode and the other side to a good ground then adjusted the voltage output while watching an amprobe around the output you could figure the resistance.

My real question would be how would you know the resistance of the 'other' grounding point?
 
Dennis Alwon said:
Unfortunately not everyone thinks that is so. At our last NC association of EC's meeting we had about 20 members there and I was the only one that takes advantage of the CEE. A few inspectors where there and they said the wording is still ambiguous since it is not available when the EC arrives. Doh.
Click to expand...
Those inspectors know something I don't. Please ask them where in any Code that it states rules need not be complied with if the proper contractor is not there? :) :D

Back to the OP, we have always condsidered "where available" to mean that the CEE is available before the concrete is placed. The argument would always come up that the electrical contract was not let yet. I would always say hire someone for a one day job.
 
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sandsnow said:
Dennis Alwon said:
......
.........Back to the OP, we have always condsidered "where available" to mean that the CEE is available before the concrete is placed. The argument would always come up that the electrical contract was not let yet. I would always say hire someone for a one day job.
Click to expand...

The CMP removed the word "available" to be consistant with the NEC Style Manual which advises against references that are vague and unenforceable. "Available" was intended to indicate "accessible" and "Present" now clarifies it as "being at the specified location", or "at hand". :smile:
Click to expand...
 
Dennis Alwon said:
Well I was smart enough to look on the internet and find a picture but how is this used to test the ohms on a cee vs a ground rod?

I believe your original response was to my ohms question.
Click to expand...
I wanted it to be. I believe that a typical ohmmeter's battery does not give a real indication of a grounding electrode's ability to carry appreciable current.

iwire said:
IMO you really could not use it to get a good answer.

In theory if you hooked one side of the variac output to the electrode and the other side to a good ground then adjusted the voltage output while watching an amprobe around the output you could figure the resistance.

My real question would be how would you know the resistance of the 'other' grounding point?
Click to expand...
Since a Variac, like other auto-transformers, has a line common to the input and output (i.e., the grounded conductor), you'd only have to run the line conductor to the electrode.

I would be hesitant to merely run a conductor straight to the electrode without a way to limit the current while ramping up the voltage. Once a round current number, say 2, 5, or 10 amps, is reached, a clamp-on and math will give you resistance.

True, you don't know the exact resistance of the rest of the current pathway, but you can get a realistic idea, since you'd be using the same current pathway that real fault current would follow. Maybe it's a silly idea, but it makes sense to me. :roll:
 
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