Equipment grounding conductor sizing

Status
Not open for further replies.
B

britt

Member
Location
Texas
One method our company uses to bond all the interior metal piping in a dwelling unit as stipulated in 250.104 is to size the GEC to the water pipe entering the dwelling per 250.66. We then extend this to the hot water pipe. My problem is that the AHJ says that the equipment bonding jumpers must be added together to size the proper GEC. For example if I had 4 metal interior pipes and I bonded them using 250.l22 which is probably going to be a 12AWG because the circuit most likely to engergize the piping would be a 20A CB, the AHJ wants us to add the total cmil area of the bonding jumpers and add that to find the required GEC. He says he got this method from a grounding seminar. I know and can prove that this is not required by the NEC or the IRC but I just wanted some feedback before I go before the city council if it comes to that.

Thanks in advance
 
Re: Equipment grounding conductor sizing

Is the piping you are discussing water piping or "other piping"?

Water pipe bonding is sized to 250.66, other piping is sized to 250.122, as per 250.104(A) and 250.104(B)
 
Re: Equipment grounding conductor sizing

These would be interior metal water pipes (hot and cold water) and also interior gas piping.
 
Re: Equipment grounding conductor sizing

As I said in the original post the AHJ wants us to add all of the bonding jumpers that are connected to the interior metal piping and taking that cmil and adding that to the size required by 250.66 and coming up with a new size. I just spoke to him by phone and he says he got this information from a seminar from some building institute, he couldn't remember the name, and that the speaker was on CMP-1, he couldn't remember the name, and that it was in 250.
 
Re: Equipment grounding conductor sizing

I did. He said he didn't have time to look for it but it was in there. He said that he would listen if I got a formal code interpretation. I think we'll have to go before city council to argue the case. This is not an example of winning the battle but losing the war. This could be a significant cost increase in wiring if we have to do this.
 
Re: Equipment grounding conductor sizing

He said he didn't have time to look for it but it was in there. He said that he would listen if I got a formal code interpretation.
Click to expand...
This is too rich! :eek: Instead of him taking a few minutes to look up in the NEC to prove he is wrong, he wants you to get a formal interpretation. Riiiight...Throw me a freakin bone here! (ala Dr Evil)
 
Status
Not open for further replies.
Top