I have a client with an industrial building divided into individual suites. There are 10 250 watt hps wallpacks around the perimeter. 9 are on a 12 wire ckt and 1 is on a ckt by itself. It was an incompetent electrical job. I wired a pc and contactor to eliminate timeclock problems. The ckt carrying the mojority trips from time to time. Last trip I amprobef it and noticed fluctuations where draw accelerated to 23 amps and decelerated to 16 amps.