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Posted By: jes 'Metal Water Piping System' - 12/31/05 02:45 PM
Does anyone live in a jurisdiction where metal soil pipe (DWV) is considered part of the 'metal water piping system' and is therefore required to be bonded? Does anyone do this as a matter of course? What are the criteria to select the bonding jumper and do you connect together sections that may be separated by plastic?
How about using it as a grounding electrode if it exits the house underground?
Posted By: iwire Re: 'Metal Water Piping System' - 12/31/05 02:52 PM
Personally I would not call what is in that pipe 'water'.

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250.52 Grounding Electrodes.
(A) Electrodes Permitted for Grounding.
(1) Metal Underground Water Pipe.


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250.104(B) Other Metal Piping. Where installed in or attached to a building or structure, metal piping system(s), including gas piping, that may become energized shall be bonded.....

Do you think the waste pipe may become energized?

I think that would take very unusual circumstances.
Posted By: renosteinke Re: 'Metal Water Piping System' - 12/31/05 03:51 PM
I suppose that bonding the drain pipe isn't a bad idea. This would even be desireable in the case of a sump pump, or a 'pump-up' toilet, or other electrical equipment being present that uses the drain line.
In that case, I would prefer to make my bond at the equipment, rather than to a main line. Even cast iron pipe is assembled in a manner that may provide a poor connection between separate pieces. So let's put the electric "drain" near where the electric "leak" is likely to be!
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