Home>Discussions>ELECTRICAL & LIGHTING>Water pipes bonded to grounding rod
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silentsound
Re: Water pipes bonded to grounding rod
silentsound wrote:

Water pipes are metal, but bonding to them 5' from the service entrance will be rather hard. It was never bonded there when the house was built/inspected (any idea when the 5' feet rule was added?).

To answer my own question, I found a post on in Mike Holt's Forum indicating the 5 ft. rule was added in the 1993 NEC edition. I can't find a copy of that edition or its ROP online to confirm, but that would certainly explain it since this house was built in 1985.

Timothy Miller
Re: Water pipes bonded to grounding rod

Howdy one last time. Some locals do not allow bonding to gas lines so opsee i should of suggested you check with the local electrical inspector....
Is the reason for the bonding so close to water main line entrance that a short will run to ground in a millisecond if bonded within 5 foot of entrance verses running threw allot of plumbing to ground otherwise?

Re: Water pipes bonded to grounding rod

The requirements for ss gas lines are a bit confusing and I think there will be some changes to it in the next cycle, and this isnt something I am very familiar with so..

Is it required to be bonded to the GEC loop or only required to bond between the ss gas line and the appliances it serves? (I wonder what the manufacturer says)

I was under the impression that we are NOT supposed to bond it to the GEC because that would in effect make it an intrinsic part of the GEC loop. (sees likea bad idea to me, the possability of a fault current on a gas line?) However eliminating a difference in voltage potential between he gas line and appliance would prevent any possable arc.

I guess I am looking for clarification on wether it is to be grounded or bonded.

Are we getting books out again?

OP, if the nuetral is bonded to the gec in the main disco outside (as it should be) then be certain the grounds and nuetrals are seperated in the sub panel inside. Use 2 rods 6 foot apart, outside and run the waterpipe bond to a point as close to that 5' requirment as you can, then jump out anything that could create a differnce in potential, such as hw heater, water meter (even if it is outside) any sections of pvc pipe or fittings, water softener, and I would even go as far as jumping the hot and cold and a secondary point such as under a sink or behind the washer (while this may possably reduce any likelyhood of any difference in potential the real reason to do it is to show an improvement over existing), while this wont exactly meet todays minimum requirement it should be acceptable as an improvement to what is existing. IMO

Ernie_Fergler
Re: Water pipes bonded to grounding rod
Shaun wrote:

I believe the op is saying the gas pipe is grounded not that systems are grounded to the gas line. Interior gas piping is required to be grounded in Mass. if the system uses Csst (corrugated stainless steel tubing).

I could see that, but inspectors in these parts tend to frown upon that. As you state a local or commonwealth issue.:)

Ernie_Fergler
Re: Water pipes bonded to grounding rod
Timothy Miller wrote:

Howdy one last time. Some locals do not allow bonding to gas lines so opsee i should of suggested you check with the local electrical inspector....
Is the reason for the bonding so close to water main line entrance that a short will run to ground in a millisecond if bonded within 5 foot of entrance verses running threw allot of plumbing to ground otherwise?

Nice one about the millisecond !!!!:D
The reason the bonding must be so close to the main line entrance is keeping Joe Handyman honest. Say the water main is broken in an accident, Joe H runs in with PEX and Sharkbites to the rescue. Well the water problem is quickly fixed, but the water main grounding is lost in the process.

silentsound
Re: Water pipes bonded to grounding rod

Thanks again all for the replies.

I have a follow-up question to this. Since I now have to relocate this #6 AWG GEC, I need to splice it. Re-running it isn't possible without significant wall damage to rooms I'm not touching.

I've got 2 options:

  1. Splice it in the ceiling
  2. Run the existing one to the subpanel (which is in between) and run a new one from the panel to the water pipes (preferred)

For #1, I've read the NEC section on splicing and dug around on the forums. But I'm unclear what type of compression fitting I need. Looking at page 2 of this Thomas & Betts catalog, I'm thinking a C-tap or C-crimp.

For #2, do I just attach the original #6 to the ground bus bar in the panel and the #6 to the pipes to that as well? Why wouldn't they have done it that way in the first place instead of running a separate #6 from the pipes all the way to the grounding rod outside?

Thanks again!

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