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Posted By: HCE727 Fluorescent Trouble - 02/15/07 01:45 PM
A switch controls a bank of 2x4 drop in, 277, 3 tube bi-pin fluorescent lights with electronic ballasts. One fixture, in the middle of the run is not working. The ballast was replaced, 2 new tubes are put in and it works, put the third tube in an the light goes out. The fixture is replaced with another from a different location. The third tube is put in and the light goes out. The switch is flipped a couple of times and all of the light come on. The switch is flipped again, the fixture and the one next to it go out. The original fixture is put in another location and works fine. What could it be?
Posted By: Zapped Re: Fluorescent Trouble - 02/15/07 02:55 PM
That's a good one.

First, I'd bypass the switch to see if that's the problem.

Then I'd do a voltage reading under load at the middle fixture to see if there is a bad connection somewhere causing a VD or intermittent power.

Then, I'd go through the lamp sockets and internal wiring of the fixtures to see if there is anything causing the short-circuit protection of the ballasts to activate. Get the fixture lit and then jiggle the lamp a few times to see if causes the fault/shutdown.

Good Luck!
Posted By: HCE727 Re: Fluorescent Trouble - 02/15/07 03:37 PM
Voltage is ok, this fixture is in the middle of about ten lights that are daisy chained. All of the other lights are working.
Posted By: frenchelectrican Re: Fluorescent Trouble - 02/15/07 03:38 PM
but i dont know if you knew this or not some ballast did have multi light level on the ballast so you may have to cycle the switch few time to get it all light up

i know one Advance ballast do this way

hit the switch all 3 tube will be on then hit again switch to 2 or 1 tube set up and again back to all 3

sorta of 3 way light bulb work so just a thought

the other thing is that some lumiaire if you have " remote " type check the ballast for max distance if too far it may not fire up not very well at all

Merci , Marc
Posted By: HCE727 Re: Fluorescent Trouble - 02/15/07 07:59 PM
Nope, not it
Posted By: wendel Re: Fluorescent Trouble - 02/15/07 08:29 PM
Are you using bulk tubes or name brand? Did you wipe the tube of any dirt/film. Is the fixture securely grounded? I've been fighting a similar battle with mixed success.
Posted By: HCE727 Re: Fluorescent Trouble - 02/15/07 11:58 PM
The tubes are brand name, the tubes were never wiped down and the fixture is properly grounded.
Posted By: jdo1942 Re: Fluorescent Trouble - 02/16/07 01:14 AM
Posted By: HCE727 Re: Fluorescent Trouble - 02/16/07 01:20 AM
Why is it the fixture in the middle and the one next to it, in a bank of about 10 lights. All of the lights are controlled by one switch. The other lights work fine. There is also another problem in another office in the same building, but on another floor.
Posted By: Jps1006 Re: Fluorescent Trouble - 02/16/07 01:17 PM
Are you lamping these while energized? I have read on certain fluorescent ballasts before "do not lamp while energized. Lamp will not properly light"

Is this switch rarely operated and left on overnight? Just a stab, but.... excersing the switch reset the ballast that was lamped live and the light next to it was just waiting for a reason not to come back on, it was close to its end of life.
Posted By: earlydean Re: Fluorescent Trouble - 02/16/07 05:41 PM
I'd check for loose connections at a J-box in the ceiling feeding the suspect fixtures. Perhaps in a shared neutral return with the fixtures next door? A neutral pinched in the ballast cover could allow enough current flow to sometimes strike the tube.
Posted By: HCE727 Re: Fluorescent Trouble - 02/17/07 05:31 AM
All connections were checked, working back to the switch. A suspect ground was respliced, which was thought to be the problem. All of the light worked fine after that. Then the problem started again.
Posted By: frank Re: Fluorescent Trouble - 02/18/07 03:56 PM
It will either be a ground or the sockets if you have replaced the ballast already.Most likely the sockets.The stab locks can be bad out of the box.Either the connection is no good or oxidation has set in making it resistive.And you just can't see it until you break it open.The wire will have a green coating where it was in contact with the spring.I have pull plenty of hair out over this myself.

[This message has been edited by frank (edited 02-18-2007).]
Posted By: HCE727 Re: Fluorescent Trouble - 02/18/07 05:38 PM
It cannot be that, the original fixture that started this whole problem was relocated and it works fine.
Posted By: hbiss Re: Fluorescent Trouble - 02/19/07 04:44 PM
Believe me, I feel your pain. I have the same problem with a store full of F12 U tube fixtures. Some work, some don't, all are daisey chained also.

I replaced tubes, used another brand tubes, used energy saving and full wattage, replaced the ballasts, checked ground and voltage all without success.

Out of despairation I take the ballast (electronic), both tubes and the strip that holds the sockets out of the fixture and bring it all back to the shop.

I set it on a wood workbench (remember, not even a ground). Connect the ballast leads to a cord and plug and it works perfectly. Use ANY of the tubes I tried back at job and they now work perfectly too. I put some aluminum foil under the tubes to simulate the grounded fixture sheet metal. I ground it to the ballast case and the receptacle ground. Now they light even faster.

I can't see anything wrong with the sockets or wiring but I replace the sockets just so I can say that EVERYTHING electrical is new.

I bring it back to the store and now it's been working since. Don't ask me why. I'll let you know what happens with the others.


[This message has been edited by hbiss (edited 02-19-2007).]
Posted By: gfretwell Re: Fluorescent Trouble - 02/19/07 05:20 PM
Incandecent lights are AM, Flourecents are FM
Posted By: HCE727 Re: Fluorescent Trouble - 02/20/07 02:41 AM
hbiss, I had that problem with the u-tubes before, but solved it with the help of another electrician. I am not sure what make the tubes were, but the tubes with the meatal brace gave me fits. I changed the tubes with the plastic brace, and never had a problem.
Posted By: smokey Re: Fluorescent Trouble - 02/20/07 03:02 AM
sounds like u have a neutral problem
Posted By: hbiss Re: Fluorescent Trouble - 02/20/07 08:30 PM
I changed the tubes with the plastic brace, and never had a problem.

Matter of fact the tubes I tried were of both types- metal and plastic.

Neutral problem huh. Don't think so.


Posted By: wendel Re: Fluorescent Trouble - 02/20/07 08:57 PM
Since you gentlemen and ladies in the business have access to some of the manufacturers, have you ever tried to get an answer from one of their design engineers? I know it may be impossible to get through the phone system but one would think the design engineers would know exactly what's happening or what problems they have encountered in their tests. And hopefully they may have some solutions.

I know I have struggled with the poltergeists of fluorescent lighting and would love to better understand its idiosyncrasies.
Posted By: smokey Re: Fluorescent Trouble - 02/21/07 12:29 AM
check your breakfast for tampering lol
Posted By: hbiss Re: Fluorescent Trouble - 02/21/07 01:19 AM
Wendel, that was exactly what I was thinking. We all started having these problems back when everything went energy saving/low mercury. I previously had luck by switching to another lamp manufacturer but this time that didn't work. Since everything is new this has to be a manufacturing problem somehow. Either the lamps or ballast.

And you may be right too about the poltergeists. The owner swears the place is haunted by the old guy who lived in this house that the owner made into a store when the old guy died. I even told him to get a priest or rabbi in to see if he could get the lights to work.

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