2' x 2' Troffer Fluorescent Fixture

[Handy Matt]

It was more than a year ago when a friend and I built an office in a basement for a customer. The office has a drop ceiling with 2 troffers. Both troffers take 2 "U" fluorescent tubes. They worked fine at the beginning. After awhile the lights took several seconds to a minute or more to come on full strength. I replaced both ballasts a few months later and it seemed like it was back to normal operation. The same problem has developed. The lights will, on certain occasions, go on normally, but more often it takes several seconds to more than a few minutes to work properly. Sometimes one goes on and the other does not. Just yesterday I put 4 new tubes into these fixtures and it doesn't seem to have corrected the problem. Any ideas on what might be happening?

Respectfully,

Handy Matt

[ampz]

Do you have a good grounded connection thruout the circuit? Newer lay-ins require this for proper ballast function

[Cheyenps]

U-Tube fixtures do that; even the ones in my office do it. Perfect grounding seems to help, but it's not a cure-all.

I don't know why, and I have never met a lamp/ballast manufacturer's rep who will admit that it happens. I have guys tell me they cut the silver tape on the tube to make it work, and others tell me the tape is there to help it start - that the tube won't work if the tape is nicked.

What does work is T-8 U-tubes - never had one fail. If nothing else works you can change the ballast to electronic and install t-8 tubes.

[Handy Matt]

Thank you for the input. I'll have to check with the homeowner and find out how the new tubes have worked since the weekend. Go electronic, huh? What's the typical cost for a ballast and the tubes?

Handy Matt

[Cheyenps]

Thank you for the input. I'll have to check with the homeowner and find out how the new tubes have worked since the weekend. Go electronic, huh? What's the typical cost for a ballast and the tubes?

Handy Matt

The ballast is a typical 32 watt two lamp electronic ballast - maybe $20. The lamps are high - sometimes $13 - $14 each.

Outrageous, but if that's what it takes to keep the customer satisfied...

[Handy Matt]

I spoke with the customer this past week. Things have gotten worse since I installed the new tubes. He said on two occasions he's turned on the light switch and the lights did not go on the entire day. He used his desk lamp for the lighting he needed. Then he went into his office the following day, turned on the switch, and the lights went on immediately. Not a very consistent system. They left for vacation this week and will give me a call when they return.

Should I replace the ballasts that are there now, or just buy the new tubes? What specifications should I look for, besides the high price, to make sure I've got the correct tubes for this setup?

Thank you.

Handy Matt

[Cheyenps]

Should I replace the ballasts that are there now, or just buy the new tubes? What specifications should I look for, besides the high price, to make sure I've got the correct tubes for this setup?



You have to replace both the ballasts and the tubes.

You want a ballast (an electronic ballast) rated for two 32 watt T-8 lamps, and a pair of T-8 U-tube lamps for each fixture. You may have to do a bit of rewiring (moving wires around) inside the fixture. The schematic will be printed on the ballast.

T-8 tubes are easy to spot - they're quite a bit "slimmer" than the normal T-12 tube. Pin configuration will be the same.

With any luck, you'll find somewhere else to use the old magnetic ballasts. They'll work just fine in a regular 4' fixture.

[ampz]

Its very rare for lamps to go bad on two different occasions.Or to have to bad fixtures.Check the supplier to see if they've had alot of returns of the same type of fixture.I would replace the ballasts & lamps, but only after I checked the switch & its connections.I would remove the switch & connect the hot to the switch leg if the lights come on right away....you have the culprit.Good luck

[Handy Matt]

I finally have an update. And there's good news to report. I installed new electronic ballasts and tubes in the two office troffers. They work great. When the switch is turned on, the lights go on immediately. They've rarely worked this way since they were installed over a year ago.

I've also contacted the manufacturer of the troffers, Lithonia Lighting, and asked them about their fixtures. When I went to buy the ballasts and tubes I noticed that the troffer on display specified the use of electronic ballasts and tubes. That was not the case one year ago.

I received an email reply stating that the fixture needs to have a 'stable ground', which it does, plus they recommend a Sylvania full output tube. That's something I never recall being specified when the troffers were purchased. Why shouldn't any tube work? When I buy a standard fixture and put a bulb in it, as long as it screws into the socket it doesn't matter who makes it or that it has certain characteristics.

Anyone hear this about the full output tube?

Handy Matt

[Cheyenps]

What pray tell, is a "Sylvania Full Output Tube"? And did the fixture come with instructions to use one - or even where to find one?

Methinks the "Sylvania Full Output Tube" is filled with snake oil.

Glad the T-8's are working for you.

[Handy Matt]

I sent another email to Lithonia Lighting asking them about their requirement for the "special" tube. I don't remember seeing anything that mentioned that. I'll be curious to find out how they respond to it.

Handy Matt