Metal water bonding

[Knight]

NEC 250.104(a)(1) refers to Metal water piping, but it is not clear that this metal piping is a water pipe used for an electrode system. This section has you size it by an elcectrode system table 250-66.
I have an inspector saying that a plastic well to metal water pipe falls into this section.
I say that it falls under 250.104(b) which is other metal piping and an equipment ground. He says the word "Other" clearly means other than water pipe and I say "Other" means other than an electrode pipe. Has anyone run across this.
It just doesn't make sense to size an non-electrode pipe to a table for electrode pipes. This pipe is no different than any other pipe in the house which is sized by an equipment ground.

 

[jtester]

I don't believe that 250.104(A) is limited to electrode pipes, but should include the system, whether you can reach it within 5' of where it enters the building or not. Remember this is bonding not establishing a grounding electrode.

The question is whether the metal pipe you mention is "installed in or attached to the building or structure". as specified in 250.104(A). If it is, I am afraid you are incorrect. If it is entirely outside the building, you may have an argument.

Jim T

 

[don_resqcapt19]

250.104 has nothing to do with grounding electrodes. It only applies to the bonding of the water piping system. The metal interior water pipe system is coverd by 250.104(A) and requires a bonding conductor sized per 250.66. This bonding connection can be made at any point on the water piping system.
Don

 

[George Stolz]

Re: Metal water bonding

It just doesn't make sense to size an non-electrode pipe to a table for electrode pipes.

I agree with you. But for the moment, code is code. Metallic water pipes that don't qualify as an electrode (by running 10' underground) are still required to be sized according to 250.66.

This pipe is no different than any other pipe in the house which is sized by an equipment ground.

Knight, what would you use to size this interior metal water piping according to Table 250.122?

The pump in the bottom of the well is required to have an EGC connected to it, and also to the metal casing of the well (250.112(M)).

250.104(A) would be applied to the interior piping of the house, not to a well casing remote from the house.