Interior Ground Rod

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chris1971

chris1971

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Is it permissible to install an 8’ ground rod inside a building? I see nothing stating otherwise.
 
I have seen and even installed ground rods inside buildings on many occasions. Some electrical rooms in commercial buildings make it impractical to run an electrode outside.
 
Brian Stoin said:
I have seen and even installed ground rods inside buildings on many occasions. Some electrical rooms in commercial buildings make it impractical to run an electrode outside.
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I’ve done it once. I may need to do it again on another job. I can’t see why it wouldn’t be compliant.
 
I have installed in a basement but had to provide a means to inspect the ground rod connection so I used abs pipe and cap


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chris1971 said:
Is it permissible to install an 8’ ground rod inside a building? I see nothing stating otherwise.
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There was a rule **I think** about transformers somewhere in 250 that said the electrode had to be outdoors?? It was there, but I can't find it.

Beyond that, AFAIK, there are no NEC restrictions about a GE being located indoors. Guys will say it must outside right at the drip line, so it will be in good, usually damp ground but that is a design issue/opinion. There may be a problem with 250.53(A)(1)- but I don't buy that either for many buildings, esp if there is a basement.

Others have argued that in the event of a lightning hit its better for the rod to be outdoors.....apparently they aren't aware of the ufer.....or that copper water line that juts up thru a slab, both of which are also bonded to the service and will take the same hit-indoors.:D
 
Don't we always make a GEC onto the inside municipal H2O, regardless of G-rod location?

That way we can share a good strike with the neighbors.....

~RJ~
 
jaggedben said:
Done it hundreds of times, perhaps thousands.
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Can't say I've done it that many times but I did have one occasion where I installed a new breaker panel in a gym. Outside the building was surrounded by concrete sidewalks. Drilled a hole where the cinder block met the floor and shot the rods on an angle out of the building and under the sidewalk. Passed inspection.
 
I have installed rods many times inside large gear in electrical rooms along with rebar for the CEE.

As RJ mentions, the H20 connection would be inside as well as the building steel.

Roger
 
Under a building could mean dryer soil and higher resistance to earth.

I can show you some places that are sitting over high water table where that probably doesn't matter much either.
 
Who was the guy here who drove the Grod through a septic pipe years ago?

Now i wonder if the R values changed when the toilet flushed?

~RJ~
 
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