the main water line is galvanized steel from the street to the basement wall and pipes then transitons to copper piping,then to p.e.x plastic pipe to the water heater, lol then the riser is copper into the connection of the water heater. thus how do i properly ground the cold water pipe. i know this is a plumbing question as well but grounding is ussually done by the electrican if its in his contract. please any help with this would be a help since i cant find an anwser anwhere.

 

Whether the galvanized water pipe to the street is considered a grounding electrode or if your plumbing system just needs to be bonded depends if you have ground rods or other suitable electrical system ground. Regardless though, the process is similar.

You need to run 6ga copper wire if your service is 100 amps or a #4 if larger than 100 amps from the ground bus in your main electrical panel to the water pipe at the closest point to where it comes in. This wire is bonded using a grounding clamp like this:
[ATTACH=CONFIG]9153[/ATTACH]

You also need to use a similar 6ga wire and two clamps to jumper across the water meter (if it's in the house) and across the hot/cold pipes of your water heater.


Do you have a ground already? I have to ask... why are you asking?

 

You also need to add a jumper across the section of plastic pipe.

Bonding to the cold water inlet (the first connection) is the first, best suggestion for establishing a grounding electrode conductor. You should also drive two ground rods outside and bond to those.

 

#6 is the proper size for connection to the ground rod/rods, but either #6 copper or #4 aluminum is required to the water service on a 100 amp service. For a 200 amp service, the water service ground would be either #4 copper or #2 aluminum. In addition to a basement installed water meter, you also have to jumper around pressure reducing valves located in the basement.

You aren't grounding the cold water pipe, you are grounding the neutral conductor in your service panel to the cold water pipe.