underground water pipe

[hhsting]

I have building where underground water pipe come into building at two different places. The building is so big that their could be two different underground water pipes coming up but this NOT know for sure everything is underground.

I assume regardless if not know if both underground water pipes are different electrodes or not it is safer to connect grounding electrode conductors from one main service equipment at both places where underground water pipe come up but not sure.

So it is not clear if the grounding electrode conductor(s) should go to both location of the underground water pipes where they come up or should the grounding electrode conductor go to one of the underground water pipes? Does code say anything about above situation?

 

[tom baker]

Yes the code does address this. See 250.50
If the water pipes do not meet 250.52 A 1, then see 250.104 A 1

 

[hhsting]

Yes the code does address this. See 250.50
If the water pipes do not meet 250.52 A 1, then see 250.104 A 1

Ok but its NOT known for Sure if both underground metallic water pipe are metallic isolated or not. The building is fed by outside feeder and requires grounding electrode system.

In that scenario would code address the situation? Would it hurt to place grounding electrode conductor at both places lets say if they are metallically connected?

 

[tom baker]

Yes the code does address this. See 250.50
If the water pipes do not meet 250.52 A 1, then see 250.104 A 1

 

[rc/retired]

IMO, if you don't know, drive 2 ground rods not less than 6' apart & walk away.
Or, have someone provide information they are grounding electrodes.

 

[hhsting]

IMO, if you don't know, drive 2 ground rods not less than 6' apart & walk away.
Or, have someone provide information they are grounding electrodes.

providing two ground rods for sure. The under ground water pipes are grounding electrodes but not sure if they are electrically and metallic Not isolated from each other. So the question is would one GEC be required or two GECs require?

 

[Joe.B]

If you're doing two grounds rods then I would treat your connections to water lines as bonding not grounding.

 

[rc/retired]

providing two ground rods for sure. The under ground water pipes are grounding electrodes but not sure if they are electrically and metallic Not isolated from each other. So the question is would one GEC be required or two GECs require?

As posted above 250.50, All grounding electrodes present shall be bonded together.

 

[hhsting]

As posted above 250.50, All grounding electrodes present shall be bonded together.

So then one GEC to either underground water pipe location would be sufficient?


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[petersonra]

So then one GEC to either underground water pipe location would be sufficient?


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As I recall, an UG water pipe is never sufficient to serve as a GES. It has to be supplemented by something.

I don't see an exemption from having to bond the UG water pipes together just because there is more than one.

However, you might be able to use the building steel as the bonding means.

 

[Hv&Lv]

So then one GEC to either underground water pipe location would be sufficient?


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The way you describe it I would hit it in both places

 

[hhsting]

The way you describe it I would hit it in both places

These are two different threads posts. Post #1 here says I am not sure if the water pipes are isolated or not. Other thread post has totally different scenario which later I found is useful in my situation.

To avoid confusion I had requested Dennis to delete this thread before I even created the other thread thru PM not the other way around. Unfortunately he has not responded


The scenario in post #1 here is of no use to me but different scenario on another thread post is useful

 

[Dennis Alwon]

Sorry, I closed it but did not delete it. The other thread is the real situation