As some of you know from chat, I had to troubleshoot a string of pole lights that tripped the breaker due to one shorted ballast. Lots of shoe leather.
I have heard some people put fuses in the pole bases. Sounds good to me. Does anyone have any suggestions as to what type/class of fuse? Fast acting or time delay? And how to size? The current set up is 480 volt 1000w HPS fixtures. They are fed by a 20 amp double pole breaker.
Also I notice that bussmann makes "breakaway" holders for pole lights, at least that what their catalog says. Not sure what "breakaway" means exactly does anyone know?
My concern is of course coordination. This will not help if the breaker trips before the fuse.
Many lighting companies install inline fuses for customers as part of the service. A 1000w 480vac fixture only needs a 4 or 5 amp fuse. The installation of fuse really helps the troubleshooting, if all the lights are parallel then fuses that control each pole blows when that light has a problem.