placement of ground rod

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J

jeepx

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knoxville,tn,united states
Today I changed out a old service since it had no ground rod originally I installed one I drove the ground rod about six inches away from side of house that had about a sixteen inch overhang the electrical inspector calls me later and tells me the ground rod needed to be outside of the overhang. I have never heard of that before.can anyone tell me where to find that in the code book.
 
Some feel that the resistance will be lower if the soil around the rod is exposed to vertical rainfall. But at the depth of the bottom end of the rod the soil moisture will not vary much over the 12" distance involved.
He could just as reasonably require you to put the rod within two feet of the end of a downspout and require that the downspout go into the earth instead of being diverted by drain tile. :)
 
What is overhang? The roof line/ edge. How could he know the rod wasn't 16" over at the end of it. These type of red tags should come with article reference.
 
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I had chance to talk with the inspector again today and he said that under the overhang the ground rod could not get the moisture from rain fall I just left it at that cause I didn't wont to piss him off but sounds a little maybe bizarre but it is what it is I would have at least understood had he done a resistance test but he's the man so I just did what he asked and moved on to the next one
 
I agree with the others the inspector is incorrect. The rod has to be 8' in contact with the earth, it could be in the basement floor.
 
Just read these last 2 posts and was going to say the exact same thing.....the ground rod could be under the basement floor.

I've removed a couple of boards from a ground level deck, driven my rods and re-installed the boards.

Priced a job where the basement floor was dirt and everything outside was concrete or pavement. Called the inspector to double check and make sure I would be able to drive my rod in the dirt basement and he had no problem with it. (didn't get that job).
 
I have drilled through a 6 inch slab in the basement and drove both ground rods 6 ft apart, and the inspector had no problem. I agree the inspector is a bit off on that.
 
If he tested it and found that there was greater than 25 ohms I could see him requiring a second one, but based on his objections, he is being a Barney Fife. Personally I would call him on it.
 
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rlundsrud said:
If he tested it and found that there was greater than 25 ohms I could see him requiring a second one, but based on his objections, he is being a Barney Fife. Personally I would call him on it.
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If he required proof of greater than 25 ohms ( due to poor soil conditions as it may be obvious) you could test it and prove him wrong (never seen a single rod system without supplemental comply in my area) or add another ground rod. Separation is the only requirement of the rods but location from the house is not defined. Has anyone out there witnessed a single ground rod 25 ohms or less? if so, what was the soil conditions?
 
250.53 A
(1) Below Permanent Moisture Level. If practicable, rod,
pipe, and plate electrodes shall be embedded below permanent
moisture level. Rod, pipe, and plate electrodes shall be
free from nonconductive coatings such as paint or enamel.

If practicable is hard to enforce, but the AHJ wants the rod where it gets wet.
 
tom baker said:
250.53 A
(1) Below Permanent Moisture Level. If practicable, rod,
pipe, and plate electrodes shall be embedded below permanent
moisture level.
Click to expand...

What does this even mean? What if the permanent level is down 3' do you sink the top of the rod that far down? This should be removed from the NEC unless someone can actually explain what it means. :roll:
 
tom baker said:
250.53 A
(1) Below Permanent Moisture Level. If practicable, rod,
pipe, and plate electrodes shall be embedded below permanent
moisture level. Rod, pipe, and plate electrodes shall be
free from nonconductive coatings such as paint or enamel.

If practicable is hard to enforce, but the AHJ wants the rod where it gets wet.
Click to expand...

I don't comprehend this at all. (granted, I'm pretty dense).
What is a "permanent moisture level"? Sea level?
 
We have been over complicating this. Since you can't pull the first one out, just sink a second one at least 6 feet away and run a new cable to tie them all together. He won't be able to say anything is wrong with it and you can keep it under the roof line. I still disagree with his initial assessment, but I am certain you just want it done.

BTW, I cannot find anything that defines what depth a permanent moisture level is at other than using resistance testing to determine if the rod is at less than 25 ohms. It honestly is pretty ambiguous either way as moisture levels would vary depending on precipitation and soil conditions. I would call that a temporary moisture level, but what do I know.

Bob
 
The depth below the ground to the permanent moisture level will not vary by more than an inch or two between a point just outside the overhang versus hard against the footing of the house.
 
GoldDigger said:
The depth below the ground to the permanent moisture level will not vary by more than an inch or two between a point just outside the overhang versus hard against the footing of the house.
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Thank You Gold; Can you define what the permanent moisture level is? I am sure that it is different from El Paso vs Seattle.
 
John120/240 said:
Thank You Gold; Can you define what the permanent moisture level is? I am sure that it is different from El Paso vs Seattle.
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I wish that I could.
The first thing required is a definition.
I suspect that soil scientists have a workable definition, probably something related to percent moisture. But I do not know what it is.
As for being different in different places, absolutely. But it will vary from house to house based on topography and soil type as well.
Just as an inspector will not be testing ground rod resistance, I doubt that one will be measuring soil moisture versus depth either.
:)
But I can still generalize that moisture can move horizontally much more easily than vertically upward.
 
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mwm1752 said:
If he required proof of greater than 25 ohms ( due to poor soil conditions as it may be obvious) you could test it and prove him wrong (never seen a single rod system without supplemental comply in my area) or add another ground rod. Separation is the only requirement of the rods but location from the house is not defined. Has anyone out there witnessed a single ground rod 25 ohms or less? if so, what was the soil conditions?
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Mike Holt has a video where he tested ground resistance, he did get well below 25ohms but that was after using five 10' ground rods coupled together drove down 50'. It's a very interesting video. Here is the link.
 
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