Flouresent fixture keeps burning up ballasts

[inspector_guy]

I am a stae Licensed home inspector here in Louisiana. I know a fair amount about electricity, but not as much I wish I did. Perhaps someone can answer this question for me.
Will a lack of grounding cause the ballast on a flourecent light fixture to 'burn up' pre-maturely? I have a neighbor who has had three fixtures installed over her kitchen sink and none of them lasted more than a month. I took the cover off of the light switch and pulled out the tubes. It's an older house with old type romex wiring (hot leg-nuetral leg). I hope that someone can help me with this. I have seen some really bizarre wiring situations in the inspections business. Very few homes do I inspect that do not need the services of a licensed electrician.

 

[tom baker]

Re: Flouresent fixture keeps burning up ballasts

First of all thanks for your honesty and understanding of what you know and don't know.
Flouresent lights are designed to be operated with a ground, to the metal case of the fixture, so the lamps will fire. I have seen a house with Flouresent fixtures add to undgrounded wiring, some times they would work, sometimes not.

 

[jantaworn]

Re: Flouresent fixture keeps burning up ballasts

How do I delete the post anyway?

[ August 09, 2003, 07:48 AM: Message edited by: jantaworn ]

 

[jantaworn]

Re: Flouresent fixture keeps burning up ballasts

Hi Mr. Inspector

My friend told me that it could be the bulbs themselves that might be bad.They might draw too much current cause the ballast to heat up. Another thing might be. The next time you change out a ballast perhaps you should check to see whether or not the wires that go to the ends of the bulbs are shorted to the fixtures. Please with the power off and with a Ohm meter.

Be safe and good luck

 

[hbiss]

Re: Flouresent fixture keeps burning up ballasts

I take it to understand that the entire fixture was replaced including the lamp(s) each time.

I don't see why a fixture would need to be grounded in order to operate. Usually the ballast case needs to be connected electrically with the reflector or sheet metal behind the tubes for them to start. Some "U" tubes even have a foil stripe that makes contact with the spring retainer clips that hold the far end of the tube.

What I would do is try another brand of fixture, assuming they were all the same. There is alot of garbage out there. See also that the location is not abnormally hot or traps the heat from the fixture. Check the line voltage. Is it abnormally high or low? Make sure the lamps are the proper ones as listed on the ballast as well as the starter if it uses one. Last, look at how the fixture starts. Does it start up right away or does it flicker awhile. If it takes a long time to start somethings wrong. Does the customer turn it on and off all the time? This can drastically shorten its life.

 

[Guest]

Re: Flouresent fixture keeps burning up ballasts

This house may have "dirty" power. Scope the power. If necessary clean up the power. Make sure the neutral & ground are proper. Avoid voltage spikes and sags.

Here is how they work:
Fluorescent Lighting Theory

 

[don_resqcapt19]

Re: Flouresent fixture keeps burning up ballasts

awwt,
Fluorescent lights are not that sensitive to dirty power(and are one of the causes of dirty power). If it was that dirty, I would expect problems with other equipment before the ballasts. A poor connection of a ballast wire to a lamp socket can cause early ballast failure.
Don

 

[websparky]

Re: Flouresent fixture keeps burning up ballasts

I don't see why a fixture would need to be grounded in order to operate.

All electronic ballast need to be grounded according to the manufacturer's instructions.

All lighting fixtures need to be grounded according to the NEC.

 

[hbiss]

Re: Flouresent fixture keeps burning up ballasts

Lots of undercabinet and other fluorescent lights out there with 2 wire cordsets. Better ones have 3 wire cordsets and those that are hardwired obviously do have to be grounded per the NEC. None have to be grounded in order to work however.

 

[websparky]

Re: Flouresent fixture keeps burning up ballasts

hbiss,

Here is what the manufacturer says about their products. The link to the web site is at the bottom if you would like further education about electronic ballast.


APPENDIX E
Grounding


Ballast cases and fixtures must always be grounded. The ballast case may be grounded to the fixture or otherwise connected to ground. It would be hazardous to make contact with an ungrounded fixture or ballast when in operation. Neglecting to properly ground the ballast and fixture may result in the failure of certain lamps to start.

If improper grounding is suspected, check for poor contact due to excessive paint on the fixture, loose mounting of the ballast or surface rust, which may be impeding electrical contact.


Starting Aid

For reliable starting, each lamp must be mounted within the following distances of a grounded metal fixture, or grounded metal strip running the entire length of the lamp.

? T12 Rapid Star: 1/2 ?
? T12 Slimline, 800ma or 1500ma Rapid Start: 1?
? T8 Rapid Start: 3/4 ?
? T8 Slimline: 1-1/4 ?


Universal Lighting Technologies
26 Century Blvd., Suite 500
Nashville, TN 37214-3683
(615) 316-5100
www.universalballast.com

http://www.universalballast.com/techSupport/troubleshooting_guides/lin_index.html

 

[hbiss]

Re: Flouresent fixture keeps burning up ballasts

Yes. That's what I was referring to previously. Ballast manufacturers have always had this in their literature even way before electronic ballasts. Unfortunately their definition of "grounding" is the connection of the ballast case to the metallic fixture, not an equipment grounding conductor. The ballast case must be electrically connected (grounded- their term not mine) to sheet metal behind the tubes or they won't start properly. As I said, that's why some "U" tubes have the foil stripe that contacts the support clips that are connected to "ground". Even with the "grounded" sheet metal fixture behind them they still need a little help.