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Discussion Starter · #1 ·
22 yr old home and looking for a start to fix it solution:

One of my 2 dual element 48" fluorescent units in the bathroom is very slow to light up, one will light up right away but the other my not light-up for an hour or so --- but at times it will fire right up like the other one does. Nothing changes by replacing with new 48" bulbs

Question:
What would I start looking at first/second etc.?
 

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Master Electrician
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What do you mean ‘dual element 48" fluorescent’? 2-lamp fluorescent fixture?

First step is to check the wire connections. May have to check inside the other fixture too, if this one is ‘down-stream’ from the first.

If that seems okay (probably is)…You said new bulbs didn’t fix it, usually the next step is to replace the ballast.

Also being in a bathroom, the lampholders, commonly called ‘tombstones’, may be corroded from long exposure to high humidity. Definitely turn off the power to the fixture before you start inspecting them. Ballast can kick-out over 400 volts at the lampholder.
 

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Does that fixture have a starter? Not too much to go wrong with flourescents, bulbs ballasts and the occasional starter. Try swapping the bulbs, it's not uncommon for new bulbs to be defective. After 22 years, you probably need a ballast. It just may be cheaper to replace the fixture, if you can.
 

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Discussion Starter · #4 ·
2 units (four ft units) with 2 bulbs in each.

I'll start like you recommended and get back.

Thanks !!
 

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a sparky
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In My Humble Opinion, It's probably the ballast due to the age of the fixture.

For reference, here are the voltages and typical wiring of a rapid start fixture;





Now internally there are several things that can go wrong with a ballast over the years. It could range from a few of the windings in the "primary" portion of the autotransformer shorting, to a capacitor going bad. If a few of the windings got shorted over time, then the voltage delivered to the filaments would not be enough to vaporize the tiny drop of mercury in the tube and it would not light. All not replaceable, you would have to replace the ballast.

You could opt for a new electronic ballast that uses 32-watt lamps, it would consume less electricity and truth be told, it's hard to tell the difference between 2-32-watt lamps and 2-48-watt lamps when they are on. The advantage of this type is the lower number of wires and no longer the need for filament voltages for them to operate.

Cordially,
Gerry
 

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Discussion Starter · #6 ·
I removed the fluorescent bulbs and WD40 the end connectors and all is well here for the time being But I know better :)

When I get time I'll be going thru most everything suggested, Thanks all.
 

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Wait a minute. Although the fixture is 22 years old, if spraying the tombstones solved the problem they you are all set. Next time the problem arises, and it may be a long time, consider changing the tombstones.
 
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