The AHJ on a residential job last year asked us to put plastic under the panel cover (dead-front) and over the installed breakers. Just cut the plastic around the active breakers and the others were "inaccessible". The owner was GC on this though, and there were not a lot of people needing access to the panel.
I have put plastic over panels in the past for water proofing, and it has been acceptable to the AHJ for temp use.
On another note, last summer the plumbers on a small commercial job had an air compressor lifted from their truck. It was parked directly outside the open door to the space they were working in, within sight of the entire job site, on the back side of the building with little or no traffic. Denver, CO. I gotta get out of the big city!
