Shop Fittings

How do I fix flourescent shop lights that are dim?

I have a two tube 96" flourescent fixture. I replaced the ballast about 6 months ago (rapid start, not a cheapie) and I have checked the tubes to be sure they are good. Now the bulbs will not light all the way. They are dim and you can see the current swirling within the tubes. The guy at the supply house said if the ballast is good and the tubes are good, it must be the lampholders. How do you check the ballast to see if it is good or bad? Sorry, they are single pin bulbs, not HO.

Public Comments

1. turn the power off use a pencil eraser to clean the contacts on the fixture and bulbs
2. many times a ballast wont function properly if the temperature is too low (under 60 drgrees). is it in an unheated garage? i had this problem before i replaced the ballast with a eloctronic magnetic ballast Type RS . (I used to heat the old ballast slightly with a butane torch to bring it to the operating temp during the colder months) * By the way- the electronic/magnetic ballasts save energy compared to other types. *the contact points on the single-pin type lamps usually do not need maintenance,nor do the lamp-holders. I believe your problem is the ballast type. Or you can try placing your light near a heat source.
3. 1 you need to double check you wiring, that is usually the problem when the lamps wont light up fully. Is it an old F96 T12 ballast or the new F96 T8 ballast? And if so be sure that the lamps you have match the ballast. Wiring diagrams for the ballast are always provided directly on the ballast itself as well as a list of compatible lamps for the particular ballast. Since they are not high output then temperature will affect their operation but the should run just fine above 0C. Lamp holders for a 8' fixture work as a switch with the lamps removed there is no power to the ballast, when you install the lamps the power is turned on to the ballast, so its pretty unlikely that it is the sockets that are giving you grief.