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Joined: Aug 2001
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We used to "ground" through the pipe.
We now "bond" the pipe.
A similar change occurred here in the U.K. as well. Up until the 1950s it was common for the water line to be used as the sole method of grounding. Now we use a separate electrode, but the water pipe must be bonded to it.
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Joined: Jan 2004
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e57 - in your quote: The National Institute of Standards and Technology (NIST) has monitored the electrolysis of metal systems, because a flow of current at a grounding electrode on dc systems can cause displacement of metal. The results of this monitoring have shown that problems are minimal. It is mentioned that DC can cause minumal problems. Does the article mention anything about AC? For the record, I support using the qualifying water line as an electrode or bonding it if it's not qualified as an electrode. It does sound like the code panel don't trust the water pipe though because it's is in need of a suppliment. Other electrodes are probable more reliable.
George Little
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The reason I threw this out there is because I lost a dinner to it.
We all know the applications of bonding the water pipes, however, back to my original post: Nowhere in the NEC does it state you have to use a water pipe as a ground electrode. I threw every argument you guys have tossed out there, and all it states is it SHALL be bonded to the Grounding Electrode System.
The whole PERMISSABLE thing cost me dinner.
Dnk.....
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Dnk: I don't know how you are not getting this. 250.50 seems very clear to me.
Ryan Jackson, Salt Lake City
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dnk make me understand this.
Do you agree 250.50 requires us to bond the water pipe to any other present grounding electrodes forming a grounding electrode system?
Do you agree that theses electrodes that are bonded together into a grounding electrode system are required to be connected to the service grounded conductor?
If your answer is yes to both of these then how can you say the water pipe is not required to be used as a grounding electrode?
Now lets look at this from another direction.
250.50 references all electrode types.
It seems by your interpretation that none of the electrodes are required to be used.
Bob
Bob Badger Construction & Maintenance Electrician Massachusetts
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You have to be careful when you actually apply logic, otherwise your inground concrete pool is the biggest ground electrode in the system. Just don't say that out loud. ;-)
I know it will be the main grounding path when lightning hits my screen cage. That's why there is so much 8ga wire there and so many bonding lugs on the cage.
Greg Fretwell
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Sure is hard to see which way those pesky electrons are going! :-)
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Joined: Jul 2002
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Gee, I miss looking at this for a day and the replies go wild! Little flame icon and all...
Let me ask my original question again... Is anyone aware of a jurisdiction or part of the US where this is NOT done as regular practice. If so, why not?
Thanks.
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jes the areas that I have heard about not allowing the water pipe as a GEC do so for the safety of the water department workers.
A dielectric fitting is placed in the pipe and you can bond the water pipes on the house side of the dielectric fitting.
No electrical connection is allowed on the street side of the dielectric fitting.
[This message has been edited by iwire (edited 06-04-2005).]
Bob Badger Construction & Maintenance Electrician Massachusetts
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I guess it would be difficult to require all water pipes to be used as electrodes when a good percentage don't qualify as electrodes.
You could be required to prove that there is a continuous 10' of pipe in contact with the earth, which isn't easy to do in existing work.
Larry Fine Fine Electric Co. fineelectricco.com
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