Flickering Fluorescents

[dds92]

recently installed six 2' by 2' fluorescent fixtures (two per switch, all six on one breaker). two of them were flickering annoyingly so i took them back to Home Depot and exchanged them. this didnt seem to correct the problem and after about 30 minutes, they all seem to flicker slightly. also, when i shut the switch and quickly turn it back on, they are unable to fire up. i have to wait about 5 minutes, try again and then it seems to work. these are made by lithonia sold at both home depot and lowes and utilize U-shaped bulbs. i have tried multiple bulbs (i bought a case of 24) but nothing seems to correct the problem. all fixtures are grounded, but for kicks disconnected the ground at the switches to see if it made any difference, but they behave the same. HELP!

this is Home Depots description of the fixture...
"A specification premium, high performance, static T8 troffer which provides general illumination for recessed applications and is ideal for restricted plenum spaces. This 2 x 2 ft. fluorescent troffer has a 120 volt commercial electronic ballast and uses 2 U-tube 31 watt fluorescent lamps. This fixture is made for use in tee-bar ceilings. The low profile housing is white enamel steel. The door latches and hinges from either side. The diffuser is a reverse apex design."

[ September 12, 2003, 08:40 PM: Message edited by: dds92 ]

 

[bennie]

Re: Flickering Fluorescents

I would contact the ballast manufacturer. Tell them what is happening.

Check to see if the ballast is compatible with the lamps. There can be mistakes since the reduced wattage requirements.

Flourescent tubes contain mercury vapor gas. When this gas is too hot they have to cool down for a restrike. I suspect the ballasts are for 40 watt tubes.

 

[curt swartz]

Re: Flickering Fluorescents

I would contact Lithonia tech support about the problem. I don't have the number available now but will try to post it for you later.

What brand of lamps are you using? I know HD usually sell Philips which could be the problem. In the past Lithonia has designed their fixtures for Sylvania lamps. I know some people will say it doesn't matter but it does some times. I had problems with lamps starting in some Lithonia drop in fixtures in a new medical building we wired. I tried replacing the lamps but they still didn't work so I contacted Lithonia. The first thing they asked is what brand of lamps was I using in the fixtures. I told them that I was using GE lamps and they said that's the problem, I should be using Sylvania lamps. I decided to try the Sylvania lamps and the problems went away. Just recently I was having problems with some Lightolier recessed compact fluorescent fixtures starting. I decided to call Lightolier and was told that I should try Sylvania lamps so I gave it a try and haven't had any problems since.

 

[goldstar]

Re: Flickering Fluorescents

If you purchased the fixtures at Home Depot they probably sold you Phillips bulbs. I had the same situation when I tried to replace bulbs in magnetic ballast fixtures with Phillips bulbs purchased at HD. When the industry switched over to 34 watt bulbs from 40 watt, Phillips had a problem with their U-shaped bulbs igniting and they had to add that metal strip on the outside of the bulb. (The professionals at Home Depot won't tell you that but your electrical supply house will).

I know you're fixtures are electronic ballast fixtures but chances are (as Bennie mentioned) the ballasts may not be compatible with the bulbs. The easiest thing to do is try switching bulb manufacturers (i.e Sylvania) in one fixture and see if they work. If not, you'll have to change ballasts. But before doing that I would check with HD and find out what their policy is regarding replacments vs. returns.

 

[daveselectric]

Re: Flickering Fluorescents

Fixtures with electronic ballast's, require a grounding. Without a ground the fixture may flicker, cycle on and off.


Regards,

david neuman

 

[bennie]

Re: Flickering Fluorescents

dds92: Please post the resolution of this problem. I have confidence in you
Everyone can learn from the correction required.

Good luck.

Bennie

 

[big john]

Re: Flickering Fluorescents

Dave,

Do electronic ballasts reference the EGC? Floating ground = Unusual behavior by ballast?

Thanks.
-John

 

[dds92]

Re: Flickering Fluorescents

here's what i found so far. the bulbs i bought were from HD so i went back to investigate. HD guy was very nice but clueless. TRUE, all they sell is philips lamps, three different types of U-shaped ones. the bulb i tried (the flickering ones) were Philips FB32T8/TL 741/6. HD also carries a FB34-something-or-other. both are slightly narrower in diameter than HD's other item (Philips FB40 SPEC35/6). i havent tried the latter two yet but am now wondering if i should just make the move to sylvania, based upon what i read from you folks above.

the ballast has stamped on it "use only the following lamps:
F40T12ES, F40T124, F40T12, F40T10" (all of which are in the range of 0.75-0.76 amps).

i spent an hour or so trying scouring the internet trying to come up with a u-shaped lamp that matches the model numbers listed on the ballast, but it seems that they are all straight tube lamps. so my guess is that the ballast is not specifically designed for that fixture. also stamped on the ballast was a phone # (1-800-BALLAST) but of course they werent home on satuday. a sticker inside the fixture (not on the ballast) states "suitable for damp applications...blah blah...thermally protected...blah...flickering may indicate overheating." these are all mounted in a normal drop ceiling, as they are designed for. so if they are overheating (remember, they work real nicely for about 20 minutes), it must be because of the bulb...right????

 

[bennie]

Re: Flickering Fluorescents

I have heard of this problem ever since the energy savings plans took effect. The reduction in wattage is done in the ballast in this case.

By installing reduced wattage tubes and having a reduced wattage ballast, the result is a departure from the operating voltage.

I almost said to check the watt rating of the tubes.

 

[hbiss]

Re: Flickering Fluorescents

Okay. You need to come up to speed a little on the lamp abbreviations.

F40T12ES is a straight Flourescent 40watt (4ft) T12 lamp (1-1/2" diameter) and is energy saving.

From the other lamps listed on the ballast it looks like it is designed for 40 watt lamps.

B=bent or U= "U" shaped. Each manufacturer uses one or the other to describe a "U" shaped lamp. That's why you couldn't find the lamps you were looking for.

The lamps you are using- FB32T8 (bent 32 watt T8 which is 1" diameter) is not listed. Not only is it not 40 watts but the diameter is smaller so it may not fit properly or be close enough to the fixture sheetmetal. I think this is where your problem is.
You need to use a FB40T12** or a F40**/U/6 (assuming that the bend is 6" which is usually the case.)

The ** letters/numbers describe the color temperature and if the lamp is regarded as energy saving (ES). Color temperature used to be CW for cool white and WW for warm white but now there is everything in between like SP35 etc. You need to look at the manufacturers catalog to see what it means. Usually though all you need to do is get the lowest priced lamp of the proper wattage and size.

 

[Guest]

Re: Flickering Fluorescents

You have T8 lamps.

T8 lamps require T8 rated ballasts.

Your ballasts are rated for T12 & T10 lamps.

Two options:

1. Get T12 or T10 lamps.

2. Get T8 ballasts to match the lamps you bought at the depot.

T8 ballasts & lamps are required for new construction. It's part of that Title-24 stuff. Home Depot should not be selling new fixtures unless they have T8 ballasts.

 

[dds92]

Re: Flickering Fluorescents

THANK YOU HBISS. usually you can find that sorta explanation on the web but i searched and came up empty. so what youre saying is that T8 is the problem here. makes a LOAD of sense. thank you thank you! and by the way, both HD and Lowes sell these lithonia fixtures, which, as we know, call for T10 or T12 lamps. i guess they are not intended for new construction???

regarding the sylvania bulbs, it looks as though lowes sells them. next stop... LOWES.

now to complicate things more (and to illustrate how HD is more out of the loop that i am), their online description of these light fixtures clearly describes them as 31 WATT! (see the link in my above post).

[ September 14, 2003, 08:00 PM: Message edited by: dds92 ]

 

[Guest]

Re: Flickering Fluorescents

An Energy Saving (ES) lamp runs at 34 watts instead of 40 watts. You need special ballast rated for ES also. Your ballast must be rated for your lamp and your lamp must be rated for your ballast. Not sure what 31 watts refers to.

../Wayne

[ September 14, 2003, 08:22 PM: Message edited by: awwt ]

 

[goldstar]

Re: Flickering Fluorescents

here's what i found so far. the bulbs i bought were from HD so i went back to investigate. HD guy was very nice but clueless. TRUE, all they sell is philips lamps, three different types of U-shaped ones. the bulb i tried (the flickering ones) were Philips FB32T8/TL 741/6. HD also carries a FB34-something-or-other. both are slightly narrower in diameter than HD's other item (Philips FB40 SPEC35/6).

As I mentioned in my previous post, HD will not admit there's a problem nor will they take the time to investigate and train their people to tell you that there's a problem. Their focus is "customer enters store - wants 2 x 2 fixture - this bulb fits - that's what we sell" !!! Case closed. If you don't know what you're buying before you walk into HD - don't bother asking because they don't know.

 

[hbiss]

Re: Flickering Fluorescents

32 watts AND T8 is the problem here. You need a 40 watt T12 lamp.

 

[frenchelectrican]

Re: Flickering Fluorescents

i will give you good advise when the next time you get in the large box store like Home Depot or Mendards or Lowe's etc etc... what i will do is ask that person if you are getting it the first time i will ask the sale person to open the box then exam the fixure closer and some case i take the cover off and see the ballast label to make sure it state it on the box. other wise if that person refuse to open the box for you for inspection i will suggest to walk out because it is not worth to hassale with some sale person whom dont have trainng or knowage for that product that the store sell it. i intercounter it alot and what i do is read the label and make sure it is the correct one before buying it and the fixure lable will tell what type of bulbs it can take. most percentage it will label something on it


merci, marc

 

[steve66]

Re: Flickering Fluorescents

In your origonal post you said it was a T8 fixture. However, you said the ballast is marked for a F40T12 or F40T10 which would be either a T8 or a T12 lamp. Sounds like the fixture has the wrong ballast.

I would not assume the ballasts are electronic. What is the exact Lithonia part #. Something like "2SP8 2U316 120" would be a T8 lamp. A "GEB" on the end of the part # would indicate a generic electronic ballast, while no suffix would indicate a magnetic ballast.

Also, I have heard some fluorescent lamps require a burn in time. Try leaving the fixtures on for a day and see if that doesn't fix the problem.

Steve

 

[kajungee]

Re: Flickering Fluorescents

Hey Guys my first post here. Thanks for making me use my brain more.
It seems to me here, you got ripped-off at home depot.
Home depot's description of the fixture you mentioned says it had Electronic Ballast ( T-8 lamps), however your ballast itself you say is listed for T-12 lamps which are Magnetic ... Your fixture has the wrong ballast by home depots own discription.

 

[james wuebker]

Re: Flickering Fluorescents

I also beleive it's the ballast but while you're checking things, check your incoming voltage. Also check your neutral and grounding wire. These wires are probably in a junction box twisted with wire nuts which go from there to your switches. I alway check the voltages before anything.
bye now

 

[dds92]

Re: Flickering Fluorescents

so to put closure on this thing finally, i went to lowes and bought a bunch of sylvania FB40CWX6 12/CS and they work awesome! problem solved. so what have we learned - that the numbers on bulbs tell a tremendous story (like your car's VIN), that my problem was trying to shoot a rabbit with an elephant guy (T8 bulbs dont work with T12 ballasts) and that HD people are nice but probably know less than the average joe. i would like to thank everyone for their help and guidance as this issue was driving me INSANE for about 2 weeks. Now, if only HD would be kind enough to take BACK a case of T8's!!!!