Buried Ground Wire Protection


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Old 05-14-14, 05:46 PM
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Buried Ground Wire Protection

Hello again, Forum.

I just purchased a home that needs some minor electrical work completed. The service panel was replaced a few years ago without a permit, hence, no inspections. The quality of work appears good and includes 2 ground rods, but no bond to the water supply line - this due to use of PEX up to the shut-off under the house. The current pipe beyond the shut-off is old, galvanized pipe and needs to be replaced due to low water pressure.

For my own peace of mind, and for insurance reasons, I want to have the panel inspected and believe I need to add a ground wire to the water supply line in addition to the 2 rods in the yard in order for it to be signed-off.

The water line will be replaced on Friday, from the shut-off to the meter. Since the house is in the mountains (cold weather) the plumber wants to use PEX and insulation the remaining distance to the meter, which is approx 10' linear feet (straight shot).

Since we are already going to dig the trench for the plumbing, I feel this to be a good time to run the ground wire too. And since the plumber wants to use PEX, I have no other choice but to connect to the utility-side of the water supply line.

My thought was to run the insulated PEX through some 2 - 3" conduit along with the ground wire.

Questions:
  • Can I (generally speaking) bond to the utility's side of the meter?
  • Do I need to run the ground wire through PVC conduit to protect it the 10 feet? It will be ~24" below ground with no vehicle traffic.
  • Should I insist on copper to the meter instead for purposes of grounding?

Thanks in advance,

Andy
 
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Old 05-14-14, 06:44 PM
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Since the interior piping is plastic AND the pipe exiting the house is plastic, you do not need to bond to any piping. No need to bond out in the yard.

You will need 2 5/8" copper ground rods, 8' apart (I believe code is 6', but 8' is better). Most areas require these ground rods to be connected directly to the ground/neutral bar in your main panel.

From a plumbing perspective PEX (or black PE) is a good plan as your main. I personally wouldn't bother running it in conduit, especially for such a short run.
 
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Old 05-14-14, 06:59 PM
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How about none of the above? The bond to the water system only applies if the water piping is (a) metallic, (b) accessible, and (c) the bond is within five feet after the pipe enters the building. Since none of these conditions apply and since you have two grounding electrodes you are okay.

If I am mistaken then one of the real electricians will correct me.
 
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Old 05-14-14, 07:09 PM
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The two rods should be enough. Since the water line will be plastic there is no need to bond to it.
 
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Old 05-14-14, 07:35 PM
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You will need 2 5/8" copper ground rods
1/2" X 8 foot is all that is required by the NEC, but the OP already has two ground rods.

The quality of work appears good and includes 2 ground rods
 
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Old 05-14-14, 08:39 PM
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Thanks. This will save me some time and headache. The one item I should add is that the water supply trunk is PEX, but all of the branches are copper. The 2 rods are 8' apart, too.

I will ensure the ground is also bonded to the neutral bar.

AG
 
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Old 05-15-14, 06:44 AM
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The one item I should add is that the water supply trunk is PEX, but all of the branches are copper.
In my opinion, it isn't necessary to bond the copper branches to ground unless they are likely to become energized.
 
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Old 05-15-14, 09:30 AM
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The electric code would not require the copper to be bonded. It says metallic water systems which you do not have.
 
 

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