Grounding to the Waterpipe

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You can use any water pipe handy that has 10 foot of direct contact with the earth anywhere if you make your connection to said electrode outside. You are not required by the nec to connect within 5 foot of the entrance of the pipe into the building at all, unless you are connecting INSIDE the structure. Why we all ask??? Well because thats what 250-52 says, and the reason it says that is because the writers want the service grounded. That is the primary thing they are after. On the building interior, some joker might interrupt that path to the ground with pvc. Once you are outside at a metal water pipe that comes up out of the ground however, you are at the 250-52 target. Geez, how many times...... :roll:
 
In ref to assuming a metal pipe at the street (where meters around here are...) , and metal inside that it's metal all the way...
LarryFine said:
However, if that assumption is a false one, depending on an electrode that isn't one could be an issue, too.

If an inspector can say "Unless you expose 10' of pipe for me to see, we can't assume it's an electrode," so can we.

I believe it's less hazardous to be wrong treating it like it's not an electrode than being wrong treating it as one.

The shortest pathway between the electrical system bonding point and the metallic water system is the best pathway.
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The way I see it - there is little performance issue of the additional length to get to the right place (code wise) if it is an electrode - it's covered by today's code - if it's not an electrode - it's still covered by today's code.

And sure - you could dig it up... If you want to fight that war??? But if this is an older building or one could look up the last permit, or just for that matter know because they owned the building that long - then you might be beating your head against the wall... I don't know when they started using plastic pipe - but would an underground tracer wire have been included with it? You could trace it? Or have some plumber stick a video camera down it maybe???

And since this is an owner saying it - it might be the difference between your next job with him, or anyone he knows - or he could come up to battle back with you... The reason he may be bringing it up - is because every other bid he had on the job mentioned it as a requirement...

Why? If it looks like a duck... Shoot it! Why wait for it to quack?

FWIW - the water ground in my place is at the total opposite end of the building from my water shut off and entrance to the building, (water front - electrical service rear) and it was legal when it was done, I believe the code change was in the 93???
 
macmikeman said:
You can use any water pipe handy that has 10 foot of direct contact with the earth anywhere if you make your connection to said electrode outside. You are not required by the nec to connect within 5 foot of the entrance of the pipe into the building at all, unless you are connecting INSIDE the structure.
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So let me get this straight - a 10' + stick of 1/2" copper exiting the building, and going underground complies as the water ground????

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It was the 93 code when this changed BTW... Just looked it up - the wording of the change 'did not allow metal water piping on the interior of the building to be used as a GEC past 5' from the point of entrance'.... I see your point (making the attachment outside on another UG pipe) - but wonder how many inspectors would see it the same. Some might argue that any modifications down the line to the plumbing would allow an opportunity for that pipe to be disconnected from the rest of the plumbing - where it would be doubtful that the MAIN water would be....

And that is - IF you have a convenient 10'+ water line exiting???
 
Mark I do not think he is talking about 'any pipe' or a pipe 'exiting' the building.

I believe he is pointing out that you could connect to the water supply line anywhere outside the building that was accessible.
 
Lets say the supply from the street is plastic , the house all copper, there is a copper line out to a garden water spigot 20' away ,.. this would be an electrode .
 
iwire said:
Mark I do not think he is talking about 'any pipe' or a pipe 'exiting' the building.

I believe he is pointing out that you could connect to the water supply line anywhere outside the building that was accessible.
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Actually Bob, I am talking about connecting to any 10 ft or longer buried water pipe that is exiting from the ground outside, not just any pipe protruding from the inside to the outside. Its my belief that those water pipes satisfy the rules for grounding electrodes and connecting to them on the outside of the building satisfies 250.52 .

What is common around my area is lots of exterior spigots are run around the outside of the footing in copper lines and a verticle riser comes off the main run to the individual spigots. Those pipes usually are in contact with earth for ten feet or more. Why go to the other side of the structure when some water pipe such as that is available nearby. Something to watch out for is that plastic sleeve the plumbers sometimes put over the water pipes they bury.
 
macmikeman said:
Actually Bob, I am talking about connecting to any 10 ft or longer buried water pipe that is exiting from the ground outside, not just any pipe protruding from the inside to the outside. Its my belief that those water pipes satisfy the rules for grounding electrodes and connecting to them on the outside of the building satisfies 250.52 .

What is common around my area is lots of exterior spigots are run around the outside of the footing in copper lines and a verticle riser comes off the main run to the individual spigots. Those pipes usually are in contact with earth for ten feet or more. Why go to the other side of the structure when some water pipe such as that is available nearby. Something to watch out for is that plastic sleeve the plumbers sometimes put over the water pipes they bury.
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OK, I see.:)

I am out of this one, I am worn out on discussing electrodes.

We each know what our local area expects and accepts.
 
e57 said:
So let me get this straight - a 10' + stick of 1/2" copper exiting the building, and going underground complies as the water ground????

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It was the 93 code when this changed BTW... Just looked it up - the wording of the change 'did not allow metal water piping on the interior of the building to be used as a GEC past 5' from the point of entrance'.... I see your point (making the attachment outside on another UG pipe) - but wonder how many inspectors would see it the same. Some might argue that any modifications down the line to the plumbing would allow an opportunity for that pipe to be disconnected from the rest of the plumbing - where it would be doubtful that the MAIN water would be....

And that is - IF you have a convenient 10'+ water line exiting???
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Many I have run across do not see it, but then again those are the same ones who in my opinion hardly ever read or fully understand the NEC. They just ape what they saw the other J-men do when they had employment out in the field.... "Thats how we always did it". And for whatever it is worth, in my book water pipe bonding is a lot more critical than grounding water pipes is anyway, but the code wants the pipes grounded , so grounding I go.
 
macmikeman, the install you describe would be very uncommon in this area (of course, copper piping is uncommon here now, period) but your post enlightened me in that 250.52(A)(1) simply refers to "a metal underground water pipe" and not necessarily the incoming water supply.
 
I will offer an opinion as this just happened to me recently.

Our area is all copper water pipe for public systems feeding structures. Only those that are coming through the foundation as plastic are plastic per the water company. If they are copper then the entire run back to the main is copper.

1) If the main water pipe is present then it has to be bonded.
2) Since you installed a 2nd rod rather than prove <25 ohms to earth, you have met your grounding electrode requirement.
3) You can bond to the water pipe at any point it is accessible to you. Don't forget the jumpers where needed.


However,

If you chose the water pipe as your electrode then you would have to add a supplemental electrode such as a ground rod. That ground rod would have to have <25 ohms to earth otherwise you would need to add another rod, which you did. All three would be considered the grounding electrode system.

So:
If you have and use a water pipe then all three will be connected as the system.
Unless you are not calling the water pipe the electrode then it is just bonded.

But:
If you have a plastic pipe then all you need is 2 ground rods

Makes no sense since you are given the OPTION to choose the water pipe or not.

I think this section needs more clarification and to be streamlined for the next code cycle.
 
augie47 said:
macmikeman, the install you describe would be very uncommon in this area (of course, copper piping is uncommon here now, period) but your post enlightened me in that 250.52(A)(1) simply refers to "a metal underground water pipe" and not necessarily the incoming water supply.
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Lets look at it this way... (However it does go against my usual thinking and some of my previous arguments in the cases of CEE's which is different IMO.) If you have >10' entering - it is an electrode, and likewise >10' exiting... So now you have TWO ELECETRODES - the interior plumbing is not allowed to be used as a GEC in that very same code. Would you not have to ground to both???
 
Energy-Miser said:
The house was built in early 70's so most likely is copper water pipe coming in.
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LOOK - DUCKS! SHOOT 'EM!

Sorry - but is plastic piping even allowed where you are? Many places did not allow it for some time around here - and it wasn't a popular install other places... Around here it was only this year they started to allow HDPE.
 
That's been running through my head also. In macmikeman's case I believe the water lines in question remained outside so the "interior" requirement would not apply. It does pose an interesting point though if you have more than one metal water pipe with more than 10ft in the ground would you need to "hit" every one ?
At least in the CEE section they added that only one need to be used.
 
e57 said:
LOOK - DUCKS! SHOOT 'EM!.
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OK, you are adding some equipment near a pool and you have to bond it to the bonding grid, you happen across a solid bare conductor coming up and back down into the dirt near the pool.

It looks like a duck, do you bond the new equipment to it and call it a day?
 
iwire said:
OK, you are adding some equipment near a pool and you have to bond it to the bonding grid, you happen across a solid bare conductor coming up and back down into the dirt near the pool.

It looks like a duck, do you bond the new equipment to it and call it a day?
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In that case it would be reasonably easy to confirm further. Underground tracer and continuity to exposed known bonded items... Yep - it's a duck... :roll: BLAM!

In the case at hand - he's more than reasonably sure it is an electrode - just looking for an excuse IMO.
 
e57 said:
In that case it would be reasonably easy to confirm further. Underground tracer and continuity to exposed known bonded items... Yep - it's a duck... :roll: BLAM!
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Why did you're rules of ducks suddenly change?


In the case at hand - he's more than reasonably sure it is an electrode -
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Really, how?



just looking for an excuse
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I would be looking for that same excuse and not feel the least bit guilty about it knowing the NEC allows a million amp service to be ground to earth with just one or two rods.
 
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