210.63 is the section that requires the outlet for servicing the equipment.
It requires the outlet be within 25' of the equipment, so in Joe's picture there should be a few outlets at least.
As far as the roofs being designed for the weight of the equipment that is considered / required.
I doubt a structural engineer is involved when it is a small unit that would be the equivalent of a couple of people standing on the roof.
The roofs under large units must be built for it.
I was recently in a roof unit on a supper market that was tagged as weighing 18,000+ lbs.
