Hey,
I have a 400 watt HPS light that feeds some plants in the basement during the winter. When I unplugged the lamp in the morning (I reversed the day/night cycle so it also keeps them warmer during the cooler nights of winter), the circuit breaker would flip.
I also tried putting the lamp on a timer - which turned the lamp on fine, but when it turned the lamp off - the breaker would flip.
Oddly enough, I did find that if I pulled (more like quickly snatched) the plug from the wall - and I do mean quickly - the breaker would not flip - and I was able to reproduce this consistently.
So, unless you know of a timer that snatches plugs from the wall to turn them off - I was wondering if any of you knew what the problem would be? What's the deal with the breaker flipping when the load on the circuit drops - i.e. why isn't the breaker flipping when the light turns on but flips when it turns off?? I'd like to solve the problem while I have plenty of time before this winter...