Ground Rod


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Old 10-31-11, 05:06 PM
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Ground Rod

Due to some new construction I have to move the ground rod connected to a 100 amp breaker box. The rod is original to the house and is imbedded in a 6" concrete patio slab and then (I assume) into the ground. It is connected to the grounding bar by what looks like a 10 ga. romex. The patio slab is now the floor of a closed in sunroom so we have a ground rod inside the room. Question: Can I splice about 6' of 10 ga. wire onto the existing wire,lay it on the slab along side of the sill plate and then take it through the wall where I will reconnect it to a new ground rod outside the building? Also, how far into the ground does the rod have to go?
 
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Old 10-31-11, 05:17 PM
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The pros will weigh in shortly...but I'm pretty sure the ground wire must be continuous to the rods...with no splices. Also, #10 seems small for this application. I would have expected #6.
 
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Old 10-31-11, 06:17 PM
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Yes, the ground wire must be continuous to the ground rod. #8 copper ground wire to the ground rod is adequate for a 100 amp service, but you also need to ground to where the metallic water service enters the house with #8 copper or #6 aluminum.
 
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Old 10-31-11, 06:52 PM
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We always use #6 copper for the grounding electrode conductor due to the fact that if you use wire smaller then #6, it is required to be protected with conduit.
 
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Old 11-01-11, 04:26 AM
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Your typical ground rod is going to be 8 feet in length and all 8 ft has to be in contact with the soil. The top has to be flush with or below the grade surface, unless the top is protected from physical damage, but then it wouldn’t be in contact with the soil for 8 feet. I normally pound them down 2-3 inches below grade and cover it after the GEC is connected and passed inspection.

Joe and Tolyn have very good points. The GEC has to be continuous to the first electrode, but can be spliced if done by irreversible means (rarely done in residential). If your current wire is only a #10, it would have to be replaced, so no, you can’t splice it. I agree with Tolyn…use #6 so you don’t have to protect it with conduit (usually, for the most part).
 
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Old 11-01-11, 04:44 AM
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Thanks guys, you didn't leave anything for me to add that wasn't covered already.
 
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Old 11-01-11, 05:06 AM
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Sorry. My bad. Won't happen again....
 
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Old 11-01-11, 05:44 PM
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Ok, thanks for the info. I thought it would be just an easy "go do" but looks a little more involved. The rod is actually sticking up out of the concrete a good 12" and the ground wire is just connected to the top of it with a clamp. It's been there since the early 70's when the house was built so I guess I'll just leave it be and try to work around it. We're thinking about building a small closet in one corner where the rod is and probably can enclose it in that. Don't know why they did it the way they did. Sounds like it wasn't done right in the first place.
 
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Old 11-01-11, 05:47 PM
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The #10 conductor is wrong no matter how you look at it but the connection to rebar may be an excellent grounding electrode. Google Ufer ground for more information.
 
 

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