Ground rods through driveway slab

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  #1  
Old 03-20-13, 11:19 AM
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Ground rods through driveway slab

Hi all.

We recently had our old panel upgraded to a new 200 amp panel. There were never any original ground rods and I've redone all our plumbing to pex, except where the plumbing enters the house. Here is what I assume and here are my questions:

I assume I need to run #4 bare copper to the metal plumbing that enters the crawl space.

My question is about placement of the ground rods. Right outside my panel is the driveway and I would like to install the ground rods there if possible but I have 8' rods. Do they need to be completely buried into the soil or should the head be sticking up past the concrete?

The closest place without concrete right up to the foundation is about 30' away. Perhaps this is preferable to just insall them 30' away and run the ground wire through the crawl space. Again, does the head need to be submerged or sticking up for inspection purposes?

Thanks,
Justin
 
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  #2  
Old 03-20-13, 01:49 PM
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Since the ground rod(s) can be installed anyplace outside I would drive them at the 30' away location. You only are required to run #6 copper to a ground rod. They will need to be away from the foundation a little bit to avoid hitting the footing below. The rod should be driven all the way down to the ground.

Yes, Your wire going to your water pipe is required to be #4 copper for a 200 amp service.
 
  #3  
Old 03-20-13, 01:53 PM
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Thanks for the reply. I managed to get ahold of my electrician and he said exactly what you just said. Also, he said I have to bond the gas line as well.

Thanks for the help.
 
  #4  
Old 03-20-13, 02:35 PM
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I have a related question. I am using the ground rod location that is about 30' away. My electrician says I also need to bond our gas pipe. If I continue past the second ground rod I will be able to get to the gas piping. Can I use one long piece of wire to go from:

Panel --> 1st ground rod --> 2nd ground rod --> Gas pipe

It would be about 100 feet in total. The bonding at the gas line would be exterior. Would I bond it before or after the meter?

Thanks!
Justin
 
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Old 03-20-13, 09:22 PM
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he said I have to bond the gas line as well.
Your electrician told you that ? Can you ask him if he does it automatically or is it code there.

Just curious. Do you have flex line in the house or is your house feed on CSST line ?
CSST is that yellow covered flexible gas line.

I install generators and some times CSST pipe is used which calls in the need for bonding the gas system. Seems to be some confusion yet.

You can wire as you described and the ground clamp needs to be within three feet of the gas meter on the premise side. It can not be connected to flexible gas line. The steel pipe must be sanded to bare metal before installing the ground clamp.
 
  #6  
Old 03-20-13, 09:26 PM
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I don't know specifically about code but he does know that I'm having it inspected. I have hard pipe going from the meter into the attic and a few feet into the attic, then it's flex from there to the furnace. I didn't know about the sanding of the gas line first. I'll be sure to do that, after turning off the gas of course.
 
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Old 03-20-13, 10:14 PM
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In the past........as a rule.........natural gas pipes were not grounded.

It seems that the introduction of flex lines INSIDE the building is the requirement for grounding.

I can't see how adding flex lines inside a house could affect the grounding at the meter end.
My electrical inspector said that the codes are being changed to reflect the new requirements.
 
  #8  
Old 03-21-13, 08:23 AM
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Yeah it seems there is a new code every project. In case any one else is using this thread for their project, I was told that it's important to sand down the gas pipe to get to metal for the clamp.

Thanks again!

As a side note, my detached garage, which I recently finished wiring with a 100 amp main breaker panel will use the same ground rods as the main house. My understanding is that because it's a 100 amp panel (with 90 amp service) I can use #8. Is that correct?

Finally, right now the ground bus and the neutral bus in the garage panel are disconnected. Is that the way I leave it?

Thanks,
Justin
 
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Old 03-21-13, 09:51 AM
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As a side note, my detached garage, which I recently finished wiring with a 100 amp main breaker panel will use the same ground rods as the main house.
A subpanel in a detached structure requires a separate Grounding Electrode Conductor, bonded to the panel enclosure and to the Equipment Grounding Conductor pulled as part of its feeder set.

My understanding is that because it's a 100 amp panel (with 90 amp service) I can use #8. Is that correct?
8 AWG copper is rated for up to 40 amperes. 2 AWG copper is rated for up to 95 amperes.

right now the ground bus and the neutral bus in the garage panel are disconnected. Is that the way I leave it?
In a subpanel, the neutrals need to be bonded together and isolated from all paths to ground, including the panel enclosure. The grounds need to be bonded together and to the EGC, the GEC and the panel enclosure.
 
  #10  
Old 03-21-13, 09:56 AM
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It will have a separate Grounding Electrode Conductor exclusively running to the sub panel in the garage, it will just use the same ground rods since they are very close to the garage.

The #8 is for the Grounding Conductor, not any kind of supply, that has already been run.

Thanks.
 
  #11  
Old 03-21-13, 07:01 PM
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The #8 is for the Grounding Conductor, not any kind of supply, that has already been run.
I'd use #6 rather than #8.
 
  #12  
Old 03-21-13, 07:12 PM
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I already have enough green #8 to do the job. If I need to get more #6 I will but if I can use what I have I would prefer to do that. Are you saying #6 is preferred or required?

Thanks
 
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