Ground to Water Pipe


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Old 01-04-12, 04:24 PM
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Ground to Water Pipe

I want to ground my panel to the copper water pipe (in addition to the 2 grounding rods). The Los Angeles County code says I have to make the connection within the first 5 feet of the water pipe entrance into the building. My situation is the water service is from the front and the electrical service is through the back of the house. If I run the ground from 5 feet of the entrance to the panel, it will be a long 40' run. I don't mind running the line if it works (advise please). At such a run, would there be special considerations for wire type or size?

Thanks in advance for the help.

-David
 
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Old 01-04-12, 05:23 PM
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The size of the conductor is based on the size of your service. A #4 is good for 200 amps, a #6 for 100 amps.

Regardless of the length to the panel it needs to terminate on the water pipe within the 5' of entering the house. If the water line is not metallic or less than 10' in contact with the earth it will not count as a grounding electrode.
 
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Old 01-05-12, 12:21 PM
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Looks like I'll be installing a long ground wire.

Thank you very much for your help.
 
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Old 01-05-12, 06:00 PM
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The sizes pcboss quoted were for copper ground wire. In my area I see a lot of #2 aluminum bare stranded ground wire running to the water pipe ground clamp for a 200 amp service. The indoor ground wire may be aluminum, but the outdoor ground wire to the rod must be copper. By the way, if you have a pressure reducing valve or water meter where the water service enters your basement, you'll need 2 water pipe ground clamps. 1 will go ahead of the meter and PRV and 1 will go after them. Regardless, use a continuous length of ground wire and hit both clamps.
 
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Old 01-06-12, 07:39 AM
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I'm running only copper and haven't yet seen aluminum wire sold around here (Los Angeles). I'll make sure the ground is continuous from the pipe to where it enters the ground and jump the PRV. Thanks for the follow up!
 
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Old 01-06-12, 02:19 PM
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Note that you have to jump the PRV and meter (presuming they are inside the house). One clamp on the interior plumbing side and one on the street side. You don't need one in the middle.

Also, while you're at it, new installations require a jumper of the same size wire between the hot and cold lines of the water heater.
 
 

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