Fluorescent light in barn

[JoeR]

I have two fluorescent light fixtures in my barn. The one in the tack room started having problems, and I noticed that one end of the bulb was getting dark. So I replaced the two bulbs and it seemed to work fine. About two weeks later, the new bulbs are not lighting completely, and one has a real dark spot on one end like it is burning out! I adjusted the bulbs to make sure they are making contact, but this is strange. I never had a fluorescent light burn out so quickly. Did I get some bad bulbs? Do I have a ballast problem?

Thanks,

Joe

[MasterBob]

Hi Joe,

Unfortunately, your symptoms mask either possibility - bad bulbs straight from the factory...or a weak/ failing ballast. We buy our fluorescents by the case (30)...and out of the average case...2 or 3 are usually bad straight out of the box. We repackage them and return them for replacement. ...and that is what I recommend you do as well...return the bulbs for replacement. Some fluorescent fixtures require BOTH bulbs to be good in order for any of them to fire correctly...one bad bulb will effect the output of the other if this is a 2 , 3 or 4 bulb fixture. (some newer electronic fixtures are wired so that other bulbs will still fire even if one is bad...but it doesn't sound like you have this style fixture)

Exchanging the bulbs is the recommended starting point. Where you stated the fixture worked fine for weeks when you first replaced the bulbs...this does NOT indicate a bad ballast. A bad ballast will immediately fail to properly fire the bulbs regardless of what shape the bulb is in. However, it is possible that your ballast is fading internally....and signs of this can be seen as liquid leaking around the ballast. With the power off at the breaker - remove the bulbs and ballast cover and examine the ballast for any signs of leakage. If any are seen, ballast replacement is indicated. Sudden or excessive humming from the ballast is also a sign of emminent ballast failure.

Extreme temperature changes will also effect the output of a fluorescent bulb and ballast...but in your area of Florida...that is unlikely.

Due to the electrical nature of a ballast...and the extremely high voltage outputs, it is NOT possible for the average homeowner to test ballast output...the best test is with a known good working bulb(s). Start with exchanging the bulbs....and if they quickly fail as well...it's time to replace the ballast with an identical spec/output model.

Good Luck,

Bob Osgood
Master Electrician

[fivestring]

Sounds like a ballast problem.

[GaryM]

At least he shouldn't need an electronic or low temperature ballast!

[JoeR]

Thanks everyone for responding. I ended up replacing the ballast, and now it works.

When I replace the bulbs, they would not completely light. I think the starter in the ballast was not giving enough voltage to get them to light.

Thanks,

Joe

[Molerj]

I ususally find that for the price of a ballast, you can replace the whole fixture. I also think I bought my last cheapo 10.00 4' flourescent llight. They just don't seem to hold up for me. In fact, I would like to replace my 4 footers with a few 8 foot low temp. lights for out in the garage.

[Boondox]

Speaking of fluorescents for barns, have any of you guys seen the new T5 lights? The bulbs are about as thick as my index finger, but holy cow do they put out some light! I helped a friend install some over his workbench and they put out so much light we had to raise them to 12' above the ground! And this at minus 20!

Pete

[GaryM]

Sounds interesting. Where did you get the fixtures and bulbs? Does Home Depot or Lowes carry them?

[Boondox]

The only place I've seen them so far was at the Efficiency Vermont booth at a local farm show last month. EV was offering a rebate if you bought T5s because they were so energy efficient. I'll call them tomorrow to see where they might be sold.

Pete

[GaryM]

I was at the local true Value today and they had T5 bulbs, but only in 24" length and some shorter. And no fixtures. Fellow said he'd never seen a 4' T5 bulb, but that's just him.

Further information would be great.