ground rod spacing

[HOTWIREME]

where can i find literature that recommends installing ground rods at least 4' away from the foundation

 

[Little Bill]

where can i find literature that recommends installing ground rods at least 4' away from the foundation

That part usually is dictated by the POCO. At least here it is, but it's not 4'.
They require a minimum of 18" away from the foundation and a certain distance from a trench if one is used for the feed.

You might try lightning protection companies because lightning protection is a whole different ballgame.

 

[tom baker]

250.53 (A) states install below permanent moisture level, where practicable.
4 feet beyond the foundation would be past the roof edge in permanent moisture, IMO.
But your question may be a local code or POCO issue

 

[infinity]

What does below permanent moisture level mean? And how do you define below, the top of the rod, half the rod or the bottom tip of the rod? IMO it has nothing to do with distance from the foundation or past the roof edge.

 

[GoldDigger]

What does below permanent moisture level mean? And how do you define below, the top of the rod, half the rod or the bottom tip of the rod? IMO it has nothing to do with distance from the foundation or past the roof edge.

+1
The permanent moisture level in the soil cannot vary by much if anything between the soil under the roof edge and the soil beyond it.

As for the level, I would say that any part of the rod below that level would be OK, but the more of the rod that is below that level the better.

 

[infinity]

+1
The permanent moisture level in the soil cannot vary by much if anything between the soil under the roof edge and the soil beyond it.

As for the level, I would say that any part of the rod below that level would be OK, but the more of the rod that is below that level the better.

I agree, and I have heard people say that it means the rod needs to be beyond the roof line (which IMO it does not) but unless there is a NEC definition of what that actually means it's, well, pretty meaningless. :roll:

 

[tom baker]

I suspect "permanent moisture level" is very old code language. A good way to find out what it means is to submit a proposal to delete it.