Fluorescent Not Starting At Initial Turnons ?

Sep 14, 2009 30 Replies

Hello,



Put up the typical four foot (2 bulb) fluorescent light over my workbench. Bought at HD.



Sometimes it takes, literally 3 or 4 tries turning the AC switch on and off before it lights and stays lit. Other times, rarely, it'll catch on the first turn-on.



Is this, likely, a bulb(s) problem or something wrong (like made too cheaply) a Ballast problem.



Is this a typical problem ?



I see they don't use or have those little "Starter" small tubes anymore. I guess this really dates me.



If a defective Ballast, best to dump the whow thing and buy another, at Lowe's this time, or are the Ballast themselves (cheaply) replaceable ?



Any thoughts would be appareciated.



Thanks, Bob


Go ask at HD. Bring the thing back to HD?

It sounds like you lack a good ground. Make sure the fixture is properly electrically grounded.

What switch? One built into the fixture, or a switch you wired to the outlet. If the former- I'd suspect the switch first. To test it- once the fixture is on, unplug it and plug it back in. If that seems to work, even if the fixture is cold, then the switch is bad.

"Lights and stays lit"? Do you man it actually lights- then goes out? That's a switch. Or does it just flicker? That's more likely the ballast.

The cheap fixtures have super cheap ballasts. I'd replace the ballast.

Lowe's & HD buy where they can get the best deal-- neither has some magic way of buying good stuff cheaper than the other. This week HD has the deal- next week it is Lowe's.

Good ballasts can be had for $10-20. [$5 if you want to buy a lot of 6-10 on ebay]

Jim

I have had really bad luck with Lights of America brand. If it that is what you have return for a different brand. If you have another brand I would just try returning for replacement.

Try brushing your fingers down the length of the tubes, it has always worked on cheap shoplights for me.

Probably made in China?

Not unusual. The cheapie lights often only work well under ideal conditions. As soon as anything changes, including the environment, problems can start with the cheap ones. I'll bet it's worst when humidity is highest.

New bulb sometimes helps. If they show any burn marks, etc., definitely replace.

Yes, with the cheapies stuff.

Yup. That's OK though; a lot of us are dated here!

If new, bring it back to Lowes for replacement. But yes, replacement is often as cheap as bulbs and almost always cheaper than a ballast. BUT, a quality ballast might make the quality of the fixture rise significantly, so ... .

These always require a good, properly applied ground wire. A bad earth gnd can cause all of the problems you mentioned. Not only that, but things like distance from grounded fixture metal to bulbs can be critical too, so if you're bastadizing the fixtures at all or the design is bad, there's another possibility. Besides gnd, be certain Hot/Neutral polarity is correct too.

HTH,

Twayne`

Spend

Reverse the two wires going to the fixture, and ground the metal fixture itself.

I have been having the same trouble and found that brushing my fingers down the length of the bulb works. (sometimes)

If you are not just joking. Why?

Are the fixtures grounded??? They MUST be grounded to light properly.

If this makes them start they are not properly grounded

The way it works is that there is an inter\\nal field from the hot end of the fixture to your hand, capacitively coupled thru the glass, that starts the arc. This happens when the voltage differential between the two ends of the bulb is not enough to strike the initial arc. If the fixture is grounded, and the bulbs are within a couple of inches of the fixture (metal), then the arc will start from the hot end of the bulb to the fixture (coupled thru the glass) and that starts the lighting. If the fixture is not grounded, then the initial arc from the hot end of the bulb to ground does not exist, and the fixture will not light. That is why there is usually a warning on ALL fixtures about grounding the metal case of the fixture.

Thanks for the advice. I will try to ground it tomorrow. It's amazing what I learn on this group. Chuck

Irrelevant. There isn't one ground wire in my house (built in 1956) and all my flourescents work just fine.

Make sure you have the correct bulbs

Fluorescent fixtures that lack the widely-recommended grounding

*usually* "work anyway". But not always.

- Don Klipstein ( snipped-for-privacy@misty.com)

Sometimes this helps where the recomended grounding is lacking, or where the bulbs have a coating of slightly-conductive dirt/dust. The explanation is that touching the bulb can overcome the above in favor of increasing electric field intensity ("voltage gradient") within an unstarted bulb where it needs to be increased.

I would look into implementying cleaning of bulbs, proper grounding, and avoiding 34/35 watt "energy saver" versions of F40.

Furthermore, I hope you are not using the newfangled better 1-inch-wide "T8" with ballasts made for the "older stuff".

- Don Klipstein ( snipped-for-privacy@misty.com)

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