Looks like one tube doesn't have too many hours left! Were you trying to run it up to the vacuum loss by any chance?

That tube burnt out after i put up the fixture, and later the mercury migrated to the good end, but still put out a decent amount of light.

Motorela electronic ballasts usually don't run the lamp up to vauum loss....they migrate mercury! Nice neat looking setup here with a halfpiper above!!! How wide is the fixture by the way?

Interesting. I replaced a couple of tubes at school today, and out of 4, two didn't have vacuum, one was simply burnt out and the fourth was mercury starved. I relamped with 2 E-Lume tubes, 1 Philips, 1 Sylvania and 3 GE (one fixture was lampless and another one ony had one tube).

Next Thursday I'll replace a defective ballast (I couldn't today due to my teacher not having the time to assist me, considering it's 347V lighting!). So I should know by then which brand(s) of ballast they use at school. I'll try to get a few pics too!

It's wide enough to fit three lamps, and has a knockout at each end for a third lampholder.

I think i'd be adding that 3rd lamp since its all setup for it LOL

Maybe that 3rd lamp with my single lamp motorola ballast eh?

Sounds like a perfect use for that ballast