01-14-2012 03:04 PM
When I originally installed my flourescent lights in my shop I had hung them by short lengths of chain to the ceiling joists. After I finished off the ceiling, I decided to screw the lights tight to the ceiling with drywall screws. Today I had them on for about 8 hours when one went out. at first I thought it was a bulb so I replaced both of them but it still didn't work. Then the other light went out also. So I turned both of them off for awhile and when I turned them on later they both worked fine. The only conclusion that I can come to is that the ballasts are overheating because the lights are tight to the ceiling & air can't circulate around them to help them cool. Does this sound logical?
These are 8' lights with cold weather ballasts that I rescued from some old signs.
01-14-2012 04:50 PM
I think you are right on track with you conclusion. Some fixtures specifically say "Not for ceiling contact". If I were in you situation I would back the screws out, insert a 1/2 or 3/4 spacer in, and snug them back up.
01-14-2012 04:51 PM
" Does this sound logical? " Yes, BUT it was probably just the last straw. Ballasts will heat up when they are failing but it would be unusual for both to fail at the same time. Unless the area they're in is quite hot that is the only reason I can come up with. Be extra careful working on the 8' fixtures as they put out a lot of voltage to fire the lamps. See if the ballasts are leaking, that will be an indication of failure. Some of the old ballasts had PCBs in them so wash your hands after handling them and before eating. Roly
01-15-2012 06:28 AM
"The only conclusion that I can come to is that the ballasts are overheating because the lights are tight to the ceiling & air can't circulate around them to help them cool. Does this sound logical?"
Yes, this is your problem. In the shop I work in we had the exact same problem. We used 2 x 4 's crosswise as spacers, problem solved.
If you're worried about contamination from ballast leakage, wear gloves and throw the gloves away when you're done.
01-15-2012 07:38 AM
The apacer trick will solve your problem...I've done that before and it worked. Better solution would be to get some lamps made for that service, but good ones can be expensive.
01-15-2012 09:11 AM
I put spacers between the lights this morning. Hopefully it'll solve the problem. I got these for free when we scrapped out some old signs at work. (I actually have over 2 dozen of them in different garages, sheds, basement) I don't really want to replace them because they are expensive & not to mention I get free bulbs from work whenever I need them.
01-16-2012 10:38 AM - edited 01-16-2012 11:46 AM
You brought back some memories of when this job was assign to me to work on, if it was a remodel or such, as it happened 4 times, an addition to as in the multi-story wing/s onto a hospital. The dumpsters would be crammed full of 2 & 4 florescent light fixtures 4' or 8'. Mostly lay in's and in some cases surface mount. Layins you could adapt to a surface mount easily, and if the timing was right I could get all of used bulbs I could carry out. At one time there I was supplying the whole neighbor hood with florescent lights with their fixtures.
Latter in one of the summers back then, I had went to one of the old drive-in movie lots that had these shop-an-swap sales on Saturdays. Low and behold there was one of the labors from that job trying to make an extra buck selling these fixtures from his loaded pick-up. What the heck a buck is a buck, right ? I had got to know this guy from the year or so on another job some time ago, and as we leaned there against his tail gate jawing, he joking informed me he was worried about from the lack of intrest, that he might ending up giving them away.
Oh, as I was leaving he ask me to come back and be his halker, on this possable give-away, if this proved to be true latter just before closing. ""Here Ye, here ye, for this one time and only, right here step right up, you can get FREE just for the taking"",,,,,Na just not me, sorry.
Oh one more thing Michael, I was up you way this summer camping in the pensula of Door county. Yalp right when the 70 mph wind blew the whole night long, tore up the whole country side. Light out for 5 days. Comming back south towards home we stayed there just above you at the states Two rivers,,,hey guy you'all live in some might fine look'n part of this countrys neck of the wood up there !!!!!!!!!!!!!!