How many things can you spot wrong here? Heres a Cooper outdoor HPS flood thats been (incorrectly) serviced a number of times before today when I removed it from service. First thing you spot is an ELECTRONIC ballast just stuffed in the back of the fixture right next to the lamp! Of course this ballast no longer works. Second, the lamp in the fixture is a GE Chromafit 400w CDM. The ballast label reads "2.35A Max. at 120v" ...that doesnt sound like a 400w ballast to me. sounds more like a 250w. The ballast has no ANSI or wattage designation on it either. The label on the reflector and back of fixture states replacement lamp is a 400w or S51 HPS. Which the GE CDM lamp is a direct replacement for 400w HPS. I took the ballast apart and most of the components on the PCB are cooked as expected.

I guess someone converted the fixture to 250W, but haven't replaced the sticker indicating the correct lamp wattage. So when someone serviced it afterwards, he put there a lamp according to the sticker, not knowing it is in fact a wrong lamp for such converted fixture.
The ballast is (or was) most likely the real constant power output, delivering the same power into whatever load, so capable to correctly power both MH and HPS, even when each of them could have different arc voltage (I do not remember the figures, but I know such feature is quite common on electronic ballasts). The intention of using such ballast was to allow the use of both HPS and/or (C)MH lamp there, so the owner can change his mind later and so only swap the lamp.
But when a 400W lamp was inserted, it operated colder than designed, so with lower arc voltage. That mean the ballast used higher current, in order to keep the power. And this higher current most likely was, what caused the ballast to die early (even for the elevated temperature operation)

I also recently got one from ReStore the dual 135Watt 4ft VHO fixture but someone did replace the original huge ballast to small Rapid Start ballast for only two 40Watt... it burns bad ending with VHO tube... Crazy bad electrician! 

     

I have seen plenty of very similar cases in other areas than lighting, where some conversion took place, was not properly logged and/or labeled (with the mindset "I know it, it was agreed/ordered by the boss/owner, so it is clear enough the necessary consumables are different than they were") and later on someone else unintentionally used wrong parts only because he was not aware about the conversion.
I see this as quite a common problem, fortunately in most cases it become obvious for the next service guy in time, but on places, where it is not so visible (e.g. on a fixture, where the socket stayed the same, the new ballast is hidden, so it is not clear the fixture was converted, such missing labeling is really an invitation for huge problems...)

There's no proper cable restraint either, so if it's mounted where the cable could be pulled or moved it could foul against the entry hole and potentially cut through the insulation.


BG