So the TD turned on the compressor during a work call on Saturday, and left it on. Evidently to test it to "see if it works" because "it won't hold air". So he left it on for the 6 or so hours during the work call. I came in Tuesday afternoon. (72 hours later, compressor still cycling to maintain pressure [unused{for months} since it was charged, but still charged since Saturday]). I figured why wear down the equipment, waste power, and leave condensation in the tank? So I switched it off, and opened the release valves. I left a note to the TD informing him of the change of status. He sorta jokingly sorta angrily brought it up, and mentioned he was still testing it by leaving it running...? I don't know much of anything about compressor maintenance besides switching 'em off and opening valves at the end of the day, so I'd like to know some of your thoughts on the situation.