Shop Light Delayed Turn On

Jun 15, 2018 34 Replies

Got a pretty old two T12 48" tube, hang by a chain, plug-in fluorescent shop light that doesn't come on until about 60-90 seconds after powering on. When it finally does come on, it's fine.



Tried a different pair of tubes, smacking the fixture, plugging it into another outlet- no joy.



Seems easier/cheaper to just replace it- probably with a T8 fixture- than try to find and replace the ballast in this old dog.



Am i missing anything here?


Double check that the metal case is grounded.

Try fastening an extra wire to it and to a ground connection.

If that's it, then you've got a simple solution...

Costco is selling their LED plug in shop light for $30 right now. Why screw with fluorescent at all. I bought 2 the other day (I had a few I got when they were $40) and when an old T12 starts acting strange, in the trash it goes.

I'll try that.

What I neglected to mention in the OP was that it's been hanging there for years working fine. Not sure how the ground could have come loose but definitely worth a shot.

For the expense of a $15 ballast (electronic is the only way to go if you d0 replace it), I'd go with a 48" LED fixture from Costco or some other supplier for ~ $28. Thus, you are spared the PITA of taking the existing fixture apart and replacing it and still winding up with a fluorescent lamp that will be a slow start in cold weather, less efficient than the LED and...

Once you switch to the LED you will be amazed at the "instant on" and amount of light provided regardless of the ambient temperature. Replaced all the fluorescent lights in my garage with LED and love them.

GMTA! I bought mine a couple years ago and paid around $26 - $27

[snip]

I have an old (at least 20.5 years) T12 fixture that does that (delayed turn on) occasionally, and intend to replace it when it fails.

I agree. Either put in whole new fictures or do like I did to some of them in the house and just replace the tubes with the LED type where you remove the ballast and hook them directly to the 120 volt wiring. '

I have noticed that some of my LED lights take about one or two seconds to come on and some come on as soon as I hit the switch. This seems to be normal from the information I have.

I have seen some leds that I think you can just replace the old tubes but use the old ballast. Why screw with that either, just replace them with leds that work on the 120 volts and be done with it.

Ballast is probably going. look at new LED lights, they are getting cheaper.

If they are old, do they use starters? A bad starter?

If grounding the metal case solves it, then he has something else seriously wrong and a ground fault.

Yeah, replacing it with a LED.

[snip]

IIRC, those fixtures (that use the ballast) don't work with older ballasts (commonly found in T12 fixtures).

Yes.

Sorry to wander off topic, but is that quote yours? If not, can you provide attribution? I like it!

Took the sucker apart and found that a nut holding down one end of the ballast had worked loose. Tightening it restores instant on.

But the cheesy plastic bulb holders are so old/brittle that two cracked on attempted reassembly...and I ruined one of the sheet metal tabs they slide onto. Deep six!

A local Big Box was running the right Father's Day promo and I got a new T8 hanging fixture with two bulbs for $13.11 out the door!

Thanks to all for the tips.

At least you know what the problem was.

While I'd prefer LED lights, at that price the payback is too long to justify. Can't go wrong for 13 bucks

Have you tried the old bulbs in the new fixture, just to see what happens???

What I don't understand is how a loose nut on the ballast that secures it to the frame could have caused the problem? The case should never be in the active, normal current path.

the fixture. The end with the loose nut was hanging down a little so the ballast was suspended inside the fixture at a slight angle and not making full contact.

BTW, I took the new fixture out of the box earlier and was surprised to find that it's all black, including the reflective side of the hood facing the bulbs. I hung it but am not sure it's putting enough light on the workbench- the black surface not reflecting like the white surface on every shop light fixture I've ever seen.

Cheap is nice- but this may not be over yet!

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