GEC to pipe if plastic outside?

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karl riley

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Just came from a job where a GEC was clamped to the water pipe close to the water entrance point and then continued out to the service disconnect and ground rod outside.

Since there was neutral current on the pipe due to an incorrect connection from the subpanel neutral bus, I had current to measure. The neutral current flowed on the pipe to where the clamp connected with the GEC which went out to the service disconnect outside.

With a clamp-on I measured the current, which went from the panel and on the pipe to the GEC and then out on the GEC to the meter box. None of it continued out on the water pipe. From this I conclude that the town water service is plastic. So I would have the GEC from the meter box outside just go to the nearest pipe (bonding) instead of within 5' of the water entrance, since I conclude there is no water pipe grounding electrode.

But would an inspector need to visually see the plastic entrance pipe?

Karl
 
You don't have to use a water pipe as part of your grounding electrode system if it does not come in direct contact with the earth for at least 10 feet, but here lies the problem...proving that this is the case...if it really is the case. If it is exceedingly difficult to run a GEC to within 5 feet of where it enters the building, perhaps it then may be worth trying to prove.
 
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Karl, there is no way the inspector can see everything, as you know. It then becomes a matter of "what do I want to see"? (speaker as an insepctor myself)

I have not the time (nor the incination) to look at underground water services to determine if they are plastic or copper...it is simply one of the items that I don't look at. To look at this would require a seperate inspection, taking time out of my day, and more importantly, taking time away from the whole construction process. And do I really want to have a 10' deep open trench in a residential area any longer than I have to? I simply don't look at it. :)
 
Plus, there's no practical way to confirm the 10'-metal pipe in the ground with existing construction.
 
GEC to pipe if plastic outside?

ryan_618 said:
Karl, there is no way the inspector can see everything, as you know. It then becomes a matter of "what do I want to see"? (speaker as an insepctor myself)

I have not the time (nor the incination) to look at underground water services to determine if they are plastic or copper...it is simply one of the items that I don't look at. To look at this would require a seperate inspection, taking time out of my day, and more importantly, taking time away from the whole construction process. And do I really want to have a 10' deep open trench in a residential area any longer than I have to? I simply don't look at it. :)
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I agree that it is not possible to prove that the metal waterline extends under ground for 10ft. or more. I also think that if the street is more than 10ft.from the point of entrance,that there is a good chance that it is.

NEC Section 250.50 requires that the metal underground water system (if present)be uses as the grounding electrode system.For that reason I always check to see if the water line is metal or plastic.

I also always check to be sure that Sections 250.53(D)(1)and(D)(2)are meet.
 
Gec

Gec

In the town I live in the use of copper water pipes are no longer allowed only plastic is the approved method, so for me as an inspector that's no longer an issue.:grin:
 
GEC to pipe if plastic outside?

lowryder88h said:
In the town I live in the use of copper water pipes are no longer allowed only plastic is the approved method, so for me as an inspector that's no longer an issue.:grin:
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That is pretty much the same here and i suppose almost every where,but what about service upgrades in existing buildings?
 
Around here all water services are copper that I've seen.

Karl, I'd say if there were a question, then a quick discussion with the inspector would probably get everybody on the same page.

My question is, why move the existing bonding conductor at all? If a metallic water service is installed at a later date, then the NEC would still be satisfied with no effort on anyone's part?
 
Ryan, the UPC used to have a requirement for a sign on the meter if the metal water pipe is replace with plastic. Does the IPC have the same requirement?
If you can you post the section and wording?
 
Yes, I agree that it is best to just leave the connection as is. It's not carrying any current anyway.

One might call the water company to find out if it is plastic outside, but at this time hardly worth it.

Thanks for your opinions.

Karl
 
Tom - the UPC still does have a requirement for labeling the service.

Installation Standard For PVC Cold Water Bldg. Supply [IAPMO IS 8-95] Section 609.3 - Identification. A label shall be fastened to the main electrical meter panel stating, "This structure has a nonmetallic water service."

We too have plastic water pipe service in our area, but since 250.104(A) requires interior metal water piping to be bonded back to the service and sized per T250.66 what's the difference? We typically have them bond within 5' on entering the bldg. [as this is usually an easy to get to location] and run their 'bonding' conductor back to the panel.....easy to confuse this with the GEC since it is the same size and in the same location.
 
Bonding within 5' of entry also should ensure it remains accessable in the future, because the main water shut-off should be there. (I would HOPE noone would conceal the water shut-off:rolleyes: )
 
Just finished a house that has a well, so I bonded the water holding tank which is 5 feet from where the water line comes into the house. The entire house is plastic, so only have that 4 inch nipple on the tank to bond my # 4 to. I guess I'm correct on this, the inspector didnt' say anything was wrong.
 
If the whole house is plastic what are you bonding? You don't need to bond a plastic water system... You do need to bond the well casing though...
 
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I kinda figured the same way...nothing to ground on a plastic water system, guess the area inspector makes the call. The casing of course is bonded, and uf run back to the house. Just interesting
 
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