Flickering Flourescent lights

[kirbydog]

I am a residential home inspector. I inspected a house that had flourescent light fixtures in the garage (4 sets of double 4' fixtures) all hardwired to the wall switch. All of the fixtures exhibited a faint flicker. The Owner said they were worse before she just replaced the bulbs 2 days earlier, but they still have a slight flicker that is annoying. The buyer wants to just put in new fixtures. I would hate to see her go through the expense and trouble if unnecesary.

Any suggestions on what can be causing this? If a ballast was going bad, wouldnt just one fixture be flickering?

Could it be a loose wire not properly clamped in the main panel.

Any help would be appreciated.

Kirby

 

[raider1]

How cold was it in the garage? Check to see what temperature the ballasts are rated for, if you have a temperature lower then the rating on the ballast then the ballasts have a tendancy to flicker or not light at all.

Chris

 

[al hildenbrand]

One other possibility:

If the garage is not cold, or, if the ballasts actually are rated for the ambient temperatures of the place, the fluorescent bulbs will flicker when new.

New bulbs may "spiral" for up to 500 hours. . .let them run until the fluctuation stops and the light output becomes uniform along the entire surface area of the tubes. They'll be fine, after that, for the rest of their life.

 

[Mr. Bill]

I'll bet these fixtures have magnetic ballasts. That flicker is the 60Hz AC current that is flowing thru the lamps. If you want to get rid of the flicker then replace the ballast with an electronic ballast. The 20kHz of an electronic ballast will not create a visible flicker. And you'll get an energy savings with electronic ballasts.

 

[tom baker]

Standard floresent lamp ballast is only rated to operate down to 60 deg. Below that the lamp will flicker. Solutions are a 0 degree ballast or a t-8 lamp with its electronic ballast. There is no problem with the fixture, its the application. If they are the really cheap big box fixtures with a tiny ballast then thats 99% of the problem.

 

[robbietan]

its a little far fetched but if the neighbors are all complaining about flickering lamps, there may be a load near them that is causing it. probably a place where metal is melted by a furnace