Interesting. I was using the 2008 edition.
The 2005 reads, in part, "containing metallic equipment that may become energized, and is accessible to livestock." That's where the E.P. is required.
So, we're still on the point of: is the metal present likely to become energized? With an all-PVC wiring method, and not accessible to the animals, I can't say it's "likely" to become energized. Nor can I stretch "may" to cover every possibility, however far-fetched. Were we to do that, there would be no need for the qualifier at all.
Nor do I consider fences and buildings to be "metallic equipment." Again, as with swimming pools, had the code panel meant 'all metal,' they would have said so. I don't see ANY equipment in the building under discussion - and I can't extend 'equipment' to cover a hend-held trimmer on an extension cord either.
