Water line bonding vs GEC

[Rob442]

I don’t do a lot of residential work and am looking into the grounding electrodes at my house. It was built in the mid 70s and has an original 200 amp service which I was looking into updating and noticed there is no bond on the waterline anywhere. My question is that if you have an adequate grounding electrode system ( 1 or 2 ground rods) would a metallic water line be considered a grounding electrode and have to be connected within the first 5 ft of entry or would it need to just be bonded anywhere for fault clearing? I understand why there’s a 5ft rule but it’s just got me curious

 

[LarryFine]

Can you either prove or disprove that there is ten feet or more of continuous metal pipe underground?

 

[infinity]

A NJ home built in the 70s would likely have a metallic water line unless there is a well.

 

[Rob442]

Can you either prove or disprove that there is ten feet or more of continuous metal pipe underground?

I could do a continuity test from point of entry to the utility shut off valve about 25’ away, but just assumed it’s all original

 

[Rob442]

A NJ home built in the 70s would likely have a metallic water line unless there is a well.

No well, city water. And I agree that’s it’s most likely metallic to the city shut off, but will verify later today

 

[ptonsparky]

IF I were updating a service and saw a metallic waterline leaving the building I would assume it qualifies as a GE. Sometimes a real PIA when it enters on the far side of a finished basement.

 

[Fred B]

IF I were updating a service and saw a metallic waterline leaving the building I would assume it qualifies as a GE. Sometimes a real PIA when it enters on the far side of a finished basement.

I suppose you could give the owner a couple of options.
1. Open walls or ceilings and fishing a GEC all the way across and thru to the pipe electrode, or
2. Bring it outside, bring it around and dig down to the waterline and make the bonding there. or
3. Same as option 2 but only come inside at the water service and bond inside.
Either way still needs a suplimental GE, and if a rod it needs a second rod. The code is kind of convoluted to get there and really needs rewording to make it clear.

 

[Strathead]

No well, city water. And I agree that’s it’s most likely metallic to the city shut off, but will verify later today

So, back to the first question, if it is metallic in contact with the earth for 10 feet or more, then you have to install a GEC to it. Or more accurately, the electrician whose license was used to build the house is obligated to install it to correct an illegal installation.

 

[Speedskater]

If there are proper ground rods why would have to call the water pipe part of the GEC system?
Wouldn't it just be a bonded metal item?

 

[infinity]

If there are proper ground rods why would have to call the water pipe part of the GEC system?
Wouldn't it just be a bonded metal item?

If the water pipe qualifies as an electrode it must be used as part of the GES. Unless there's evidence that the underground portion of the pipe has been changed given the age and location of the house the inspector would assume that it is an electrode.

 

[Strathead]

If there are proper ground rods why would have to call the water pipe part of the GEC system?
Wouldn't it just be a bonded metal item?

More specifically to infinty's statement. All grounding electrodes available shall be bonded together and be made part of the Grounding electrode system. underground water pipe, concrete encased electrode, qualifying building steel are three of them. ground rods are merely supplemental in case none of the required ones exist. Exception an qualifying underground water pipe, must be supplemented by another qualifying grounding electrode.

 

[LarryFine]

Can you either prove or disprove that there is ten feet or more of continuous metal pipe underground?

I asked because, if you don't know either way, you have to connect within 5' in case there is, and you have to use two rods in case there isn't (unless there's an Ufer).

When it was easy to show there was more than 10' of metal pipe outside, such as the inspector actually seeing the piping being installed, a single rod was allowed.

 

[jaggedben]

If there are proper ground rods why would have to call the water pipe part of the GEC system?

Just the rules. Because 250.50 says so.

 

[jaggedben]

I suppose you could give the owner a couple of options.
1. Open walls or ceilings and fishing a GEC all the way across and thru to the pipe electrode, or
2. Bring it outside, bring it around and dig down to the waterline and make the bonding there. or
3. Same as option 2 but only come inside at the water service and bond inside.
Either way still needs a suplimental GE, and if a rod it needs a second rod. The code is kind of convoluted to get there and really needs rewording to make it clear.

On a couple houses in San Francisco we had to go three quarters of the way around the back of the house because the inside was finished and the front would have been too ugly. Oh, and all in 1/2" EMT because they require it there, putatively to reduce copper theft. Was pretty much a whole second job after installing the solar.

 

[Speedskater]

OK, so where and how do you connect the metal water pipe to the remainder of the grounding system?
I would think that a wire from the GEC connection in the main box, to the nearest accessible point on the pipe inside the building.

 

[jaggedben]

OK, so where and how do you connect the metal water pipe to the remainder of the grounding system?
I would think that a wire from the GEC connection in the main box, to the nearest accessible point on the pipe inside the building.

You can run a separate GEC to the service neutral or run a bonding jumper to another electrode. Either is allowed.

 

[augie47]

If the water pipe is a grounding electrode you must connect to it within the 1st 5 ft of the pipe entering the building.
The conductor can originate at any point from the service point, the meter socket or the service panel or, as jaggedben points out, from another electrode provided the conductor to the other electrode is large enough

 

[jaggedben]

If the water pipe is a grounding electrode you must connect to it within the 1st 5 ft of the pipe entering the building.
...

Ya know the code does not actually say this in 250.68(C). It just says that if you want to connect bonding jumpers to the water pipe to connect other electrodes into the GES, you may only do that in the first 5ft. And it further seems to say that if you are doing this then any GEC connection to the water pipe must also be there. But it does not quite say that a GEC connection or bonding jumper that handles *only* the water pipe must be in the first 5ft.

That said, yours is a very common interpretation, and I haven't gone to the mat about it when it counted.

 

[Fred B]

I asked because, if you don't know either way, you have to connect within 5' in case there is, and you have to use two rods in case there isn't (unless there's an Ufer).

When it was easy to show there was more than 10' of metal pipe outside, such as the inspector actually seeing the piping being installed, a single rod was allowed.

Check 210.53(D)(2) it requires a rod suppliment comply with 210.53(A)(2) that requires a rod be supplimented by another electrode (that is not a water pipe). It would be easier if they just said 2 rods, when using a rod as suppliment. Proof of 10 ft of pipe made no difference.

 

[jaggedben]

Check 210.53(D)(2) it requires a rod suppliment comply with 210.53(A)(2) that requires a rod be supplimented by another electrode (that is not a water pipe). It would be easier if they just said 2 rods, when using a rod as suppliment. Proof of 10 ft of pipe made no difference.

250, not 210. But yes.
Should they delete the bit about 25ohms and just always require two rods? Wouldn't make a difference to me practically, but I guess in principle I'd like only one rod to be required.