Interesting option proposed for unique situation

[Joe.B]

I have a friend who has a unique scenario, I thought I would see what this group has to say. First, the house:

This is a 40's era house that has no EGC's run throughout the house. The main service has a GES that includes a copper water line per 250.52(A)(1) and two ground rods per (A)(5). At some point a previous owner had "upgraded" all the receptacles in the house to 3-prong without supplying any EGC's, and didn't add any GFCI protection. He wants to "add grounding" by connecting some of the receptacles to the copper water pipes throughout the house, where convenient. This house is not in my jurisdiction, but I was asked for my professional opinion.

First question, is this explicitly permitted by code? I said no, 250.130(C) does not list metallic waterpipes as one of the six options for the replacement of nongrounding receptacles. However, I got to thinking and (C)(1) says "Any accessible point on the grounding electrode system as described in 250.50" and 250.50 says "All grounding electrodes as described.... shall be bonded together to form the grounding electrode system."

The copper water pipes throughout the whole house are all bonded together, does that make them part of the GES? If so, could the copper pipes throughout the house serve as EGC's? Metallic water pipes are not listed in either 250.118 (A) Permitted or (B) Not Permitted. In other words, it's not permitted, but it's also not not permitted...

Second question. I told him that my recommended solution (code approved) to his problem would be per 406.4 (D)(2)(b/c), add some GFCI receptacles. He likes this idea and plans on doing so throughout the house. Here's where it get's interesting. One room of his house is his "music studio" and he's wondering if, in addition to providing GFCI protection, could he also connect to the copper pipes to provide the grounding connection he desires for noise reduction.

Thoughts?

Thanks!

 

[qcroanoke]

I have a friend who has a unique scenario, I thought I would see what this group has to say. First, the house:

This is a 40's era house that has no EGC's run throughout the house. The main service has a GES that includes a copper water line per 250.52(A)(1) and two ground rods per (A)(5). At some point a previous owner had "upgraded" all the receptacles in the house to 3-prong without supplying any EGC's, and didn't add any GFCI protection. He wants to "add grounding" by connecting some of the receptacles to the copper water pipes throughout the house, where convenient. This house is not in my jurisdiction, but I was asked for my professional opinion.

First question, is this explicitly permitted by code? I said no, 250.130(C) does not list metallic waterpipes as one of the six options for the replacement of nongrounding receptacles. However, I got to thinking and (C)(1) says "Any accessible point on the grounding electrode system as described in 250.50" and 250.50 says "All grounding electrodes as described.... shall be bonded together to form the grounding electrode system."

The copper water pipes throughout the whole house are all bonded together, does that make them part of the GES? If so, could the copper pipes throughout the house serve as EGC's? Metallic water pipes are not listed in either 250.118 (A) Permitted or (B) Not Permitted. In other words, it's not permitted, but it's also not not permitted...

Second question. I told him that my recommended solution (code approved) to his problem would be per 406.4 (D)(2)(b/c), add some GFCI receptacles. He likes this idea and plans on doing so throughout the house. Here's where it get's interesting. One room of his house is his "music studio" and he's wondering if, in addition to providing GFCI protection, could he also connect to the copper pipes to provide the grounding connection he desires for noise reduction.

Thoughts?

Thanks!

I "thought" that using the water pipe for a EGC path was no longer allowed. Because of the use of PVC and PEX.
Been wrong before.

 

[winnie]

IMHO only the first 5 feet of the copper water pipe in the home is considered part of the GES. The cable connection to a water line ground must be made within 5 feet of where the pipe enters the home.

For the music studio they should run a new cable back to the service, with the EGC run in close proximity to the circuit conductors. In addition to the water pipes not being a code compliant EGC, loop area (the space between circuit conductors or between the conductors and the EGC) is a way to turn a circuit into a 'pickup'.

 

[Joe.B]

IMHO only the first 5 feet of the copper water pipe in the home is considered part of the GES. The cable connection to a water line ground must be made within 5 feet of where the pipe enters the home.

I agree, and that's why my initial response was a solid "no". My only hesitation was that 250.68(C) is really only discussing connections between grounding electrodes, GEC's, and bonding jumpers. It doesn't describe the GES, and it doesn't explicitly contradict 250.130(C)(1).

I will share with him the concept of "loop area" or "ground loop" and let him go down that rabbit hole. But, if he makes the house code compliant by providing GFCI protection per 406.4(D)(2), would there be a citable violation if he connected the ground terminal on a GFCI receptacle to a copper water pipe?

 

[LarryFine]

Definitely new circuits for A/V and computer systems, etc.