The static strength test in 55.2.1 is then to be repeated on a locking mechanism while it is energized at 85 percent of its rated voltage. The locking mechanism shall withstand a force equal to 85 percent of its static strength rating. For a 500-pound-force rating, 425 pounds-force (1890 N) is to be the applied force; for a 1000-pound-force rating, 850 pounds-force (3780 N); for a 1500-pound-force rating,1275 pounds-force (5670 N)