Beniah Naylor
SAWHORSE
I have to disagree that the code is clear on this issue. The code is clear that the electrodes need to be bonded together to create the grounding system. It is also clear that an "auxiliary electrode" (whatever that is) does not have to be part of that system.
There is no definition of auxiliary electrode in the code that I can find, and I think it might be worth a public input to define "auxiliary electrode" when I slow down enough to submit one.
In a scenario where an electrician or an electrical engineer were to claim that the water pipe was an auxiliary electrode, I as an inspector cannot definitively tell him that it isn't by using only the NEC, since it isn't really defined, and there are indications that it might be in 250.54. I can't tell him that it is an auxiliary electrode either, because the term is not defined.
So, I would have to make an interpretation of the code, and I would have to decide, basically without guidance from the code, whether the water pipe was an "auxiliary electrode" or not. It is definitely an electrode, but it is it "auxiliary"?
So, it would come down to "Because I am the AHJ, and I said so." Which is totally legal, but you lose style points...
I would agree with Ice that it would be safer from a lightning perspective if you make them bond within 5' of the entry to the building. Safer still would be to add a section of nonconductive piping where the pipe enters the building, and then bonding at the hose bib. As an AHJ, the added safety factor is probably enough to sway the interpretation against calling the water main an "auxiliary electrode", since our jobs exist to keep people safe.
I would actually be in favor of adding an exception to 250.54 that says that pipe electrodes must be bonded together per 250.50, maybe another good public input for the future. Even if they shoot it down, that would show the stance of the code writers on the issue.
There is no definition of auxiliary electrode in the code that I can find, and I think it might be worth a public input to define "auxiliary electrode" when I slow down enough to submit one.
In a scenario where an electrician or an electrical engineer were to claim that the water pipe was an auxiliary electrode, I as an inspector cannot definitively tell him that it isn't by using only the NEC, since it isn't really defined, and there are indications that it might be in 250.54. I can't tell him that it is an auxiliary electrode either, because the term is not defined.
So, I would have to make an interpretation of the code, and I would have to decide, basically without guidance from the code, whether the water pipe was an "auxiliary electrode" or not. It is definitely an electrode, but it is it "auxiliary"?
So, it would come down to "Because I am the AHJ, and I said so." Which is totally legal, but you lose style points...
I would agree with Ice that it would be safer from a lightning perspective if you make them bond within 5' of the entry to the building. Safer still would be to add a section of nonconductive piping where the pipe enters the building, and then bonding at the hose bib. As an AHJ, the added safety factor is probably enough to sway the interpretation against calling the water main an "auxiliary electrode", since our jobs exist to keep people safe.
I would actually be in favor of adding an exception to 250.54 that says that pipe electrodes must be bonded together per 250.50, maybe another good public input for the future. Even if they shoot it down, that would show the stance of the code writers on the issue.