NESC clearance requirements on the OUTSIDE of a substation fence

[k2panman]

Is there anywhere in NESC that requires clearances be maintained (trees, structures etc) that would aid a person in climbing over the fence? I can't find this wording, although I thought it was in there somewhere.

K2ofKeyLargo

 

[BlownUp]

Had to read your post twice to make sure I understood what you are asking. Section 11 covers enclosures (fences) but does not address this specific issue. I don't think that NESC addresses it anywhere. This being said a general rule of thumb we use is to strive to keep 10 feet around a fence clear and a minimum of 5 feet. We also never mount anything on the fence.

As an aside, I have seen a telecommunication box at a substation mounted just outside a fence and right beside it (inches away). Made a perfect climbing aid and the station was broken into a couple of times. The utility's answer was to raise the fence in that area. Was not a pretty sight.

 

[k2panman]

thanks BlownUp. I did some additional searching, and found nothing more in NESC. NESC 110.A.1 says: "to form an enclosure as to limit the likelihood of entrance of unauthorized persons or interference by them with equipment inside." I think this is the only wording that implies "don't let trees grow right against the substation fence or mount boxes or steps on your fence."

K2ofKeyLargo

 

[stevenal]

I know of at least one AHJ that would consider the presence of any climbing aid that reduced the effective fence height so it was below the minimum, to be in violation.