# Electrical Ground and PEX



## linuxrunner (Oct 18, 2010)

we are getting ready to run new plumbing in our circa 1930 house, I have already decided on PEX and have the tools. I have one question though, 

Currently there are MANY places in our crawl space where there are grounds attached to the copper/galvanized pipe, I counted 8 that i could see. What do you do with these when you switch to PEX?

Also previous owner had a ground attached to a iron gas line :thumbup:, I removed it when i saw it, and no problems so far. Is it possible we do not need this many grounding points?


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## rjniles (Feb 5, 2007)

I assume these grounds were to provide a ground to replace old 2 wire receptacles with 3 wire receptacles. This was never the proper way to provide a ground. Run these grounds back to the main panel or rewire the circuits with a cable with a ground wire.


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## fabrk8r (Feb 12, 2010)

linuxrunner, are you sure the previous owner attached an electrical "ground" to the black iron gas pipe? 

Could it possibly have been bonded (grounded) to prevent a blow out from lightning strike? If this is the case it's really a good thing to have, and in some places required by code.

Sorry to get off track, just wanted to make sure you are safe in the event of a lightning strike.

As far as bonding the plumbing system after converting from copper/galvanized to pex, I don't think it is necessary. There were two reasons for bonding copper and galvanized water lines. One was to inhibit corrosion, which will not be a concern with pex, except at connections where dissimilar metals meet. The second reason was to bond the plumbing to ground in the event of a short or lightning strike. If your home's electrical system is up to code I don't think there is any need to bond the plumbing. I may be wrong about that, but hopefully one of the knowledgeable electricians that frequent this site will correct me if I am.


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## TheEplumber (Jul 20, 2010)

fabrk8r said:


> linuxrunner, are you sure the previous owner attached an electrical "ground" to the black iron gas pipe?
> 
> Could it possibly have been bonded (grounded) to prevent a blow out from lightning strike? If this is the case it's really a good thing to have, and in some places required by code.


Mech. inspector made me do this awhile back. Had to bond between CW and gas to be compliant on a gas water htr. install


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## linuxrunner (Oct 18, 2010)

fabrk8r said:


> Could it possibly have been bonded (grounded) to prevent a blow out from lightning strike? If this is the case it's really a good thing to have, and in some places required by code.


Good catch, it was a wire going from an outlet ground to the gas pipe, I'll have to read up on lightning grounding but i doubt that that was the correct way to do it, especially given that the wire was a tiny 14awg. 


huh, maybe I will run new pex lines as i upgrade the electrical and pull out the spots where they ground the outlets to the plumbing. 

What about at the main electrical panel there is what looks like the ground for the panel that goes to our main water line, pretty heavy cable too. Maybe i should remove it and put in a grounding rod instead.


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## AllanJ (Nov 24, 2007)

The fat ground wire from the panel to the water pipe (near where the latter exits the house) must stay, as long as you have the metal water pipe exiting.

If you have metal portions of plumbing upstairs with plastic connecting them to the basement, then you should have ground wires from those metal portions more or less following the plastic pipe down to where the wires can be attached to the fat ground wire or to piping continuously metal over to that fat ground wire clamped on. These new ground wires need to be at least the fatness of any electrical wires or cables (usually 12 gauge) passing near the metal piping upstairs.


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## Homerepairguy (Aug 1, 2010)

AllanJ said:


> If you have metal portions of plumbing upstairs with plastic connecting them to the basement, then you should have ground wires from those metal portions more or less following the plastic pipe down to where the wires can be attached to the fat ground wire or to piping continuously metal over to that fat ground wire clamped on. These new ground wires need to be at least the fatness of any electrical wires or cables (usually 12 gauge) passing near the metal piping upstairs.


AllanJ,

If a leaking 3/4" copper "trunk" line is replaced with pex, but the 1/2" copper branch lines to the fixtures in the bathroom are not replaced, is it necessary to ground the 1/2" copper branch lines? If so, why?

Thanks,
HRG


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