Shop lights (fluorescent)

I bought an inexpensive 4' T8 dual tube light at home depot, they still sell it, 19.99 with an electronic ballast. Well, it crapped out a couple days ago, actually
it was flaky as in sensitive to temperature for a couple weeks. It lived a week short of 4 years.
I ripped it apart, ohmed out the pre heat filaments in tubes and googled the ballast manufacturer. Sunpark, SL25CW, a 6 dollar ballast. Looking for other replacements had me in the 20-30 buck range. Sunpark would mail order me a unit for about 17 bucks when you figured shiping.
So I stopped by HD, the only show near where I work and looked for ballasts, I found a GE model on sale for 15 bucks. Longer, heavier, likely better. Noticed the light I have is still available for 19.95, likely with the same ballast.
I went for the GE. Might as well limit solid waste going to the dump. I recycled the lighting unit.
Tonight, I realized that there is a lot I don't know about ballasts. The old one used the filaments to preheat. This one had three wires going out. One side of the two tubes have all pins wired together, the other side has a wire from the ballast going to each of the two pins paralleled together.
I did the google and the wiki thing. Looks like the filaments don't have to be heated to start the light. That simplistic wiring diagram was giving me pause.
I learned something today.
Wes
--
When in trouble or in doubt, run in circles, scream and shout.

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Probably Sunpak, a big player. You do NOT need to go with an exact replacement, as long as it's a UL rated component use what you can get easily and reasonably. GE, Sylvania, Fulham Workhorse, Motorola, Advance...
Unless you have special needs or an odd sized fixture that needs an odd size ballast (undercounter T5 strips) they are mostly the same - the more you pay, the more likely to get better components and it'll last longer. But not always.

Yeah, the entire strip brand new can be LESS than the replacement ballast, and you get fresh lampholders. Especially if it's an odd ballast like an F20T12 instant start that isn't a big mover.
But it's still wasteful - and while I don't have room on the truck to cart around 100 different variations of strips and wraps and troffers on the odd chance I'll need one, I can always make room for the dozen most common ballasts and lampholders.

The first day you don't learn something new, that's the sign it's time to start shopping for a nice cemetary plot on a hill...
Today's Lesson: You do know the Paper Clip Trick right? Straighten out one leg of a small clip one turn, and stick it in next to the wire to get the old wire out of the lampholder Easy-Peasy.
The new lampholders they ship with those two-wire electronic ballasts (one wire to each end of the lamp) have the shorting bar built in between the two pins. The electronic ballasts don't need to preheat the filament to get it started, they have enough of a HV start pulse - and it saves the 4 to 6 watts used to heat the filaments.
Now you have to be careful not to get them mixed up with the old-style two wire lampholders used with standard magnetic ballasts - they are marked, but sometimes that's only little letters molded into the white plastic and Not Easily Seen unless you know to look.
The split old ones are easily jumped with a short piece of wire for a new electronic ballast, but the other direction isn't possible.
Follow The Diagram and the Approved Lamp List on the Ballast Label (or the cut sheet), Every Time. They are coming out with new variations every month, and they all go together different. Like using a 4-lamp electronic ballast as replacement in a 3-lamp fixture, sometimes it matters which "extra" wire you cap and leave unused.
Used to be the only real oddities were the switch-style Disconnect lampholders sold with the Preheat Magnetic one-lamp strip ballasts - Advence RL- series. Found in elevators a lot, they open the Neutral from the Line and the Neutral to the lamp and ballast when you take the lamp out.
They usually have a BIG black D (for Disconnect) rubber-stamped on the rear cardboard insulator - but not always... The other clue is there are two white wires on the Disconnect side (one marked Line in the plastic and the other one Ballast) and a Blue with White stripe.
--<< Bruce >>--
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Thanks for the excellent cliff notes version on fluorescent lighting!
Wes
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I have a fixture in my kitchen (four strips with separate ballasts, built into a box on the ceiling) that goes intermittent when it gets humid. Cleaning the tubes helps some, but it still gets annoying having some of the tubes flicker on long after the rest, or sometimes not at all. My understanding is that the charge leaks down the outside of the tube when they're dirty and it's humid. Would changing over to electronic ballasts help minimize this at all?
Thanks, --Glenn Lyford
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On Mon, 18 May 2009 06:35:31 -0700 (PDT), Glenn Lyford

Try changing out the ballasts, period. If the house is over 25 years old, that's it. Look on the back of the ballast can for the stamped date codes.
That's an older design, and magnetic ballasts over 20 years old start losing their starting abilities as the capacitors slowly fail. I've seen them make it to 40 before they fail, but not many.
--<< Bruce >>--
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Bruce, some of the cheap fluorescent lights in my garage are going out. I want to replace them with something relatively decent, would you have any suggestions? 120v only.
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I'd like to know what other pros use too.
Assuming non high output fixtures: If you have 4' lamped fixtures and they're physically in decent shape you can retrofit T8 ballasts. T8 technolgy will start at lower temperatures and have less flicker.
You could gradually reballast as necessary to T8 electronic assuming a knowledgeable person (you) would be responsible for instaling the correct bulbs in a mixed area. As a contractor there is usually a question to the skill of the regular lamp changer so then we will replace with the existing technology (T12) to avoid improper lamps being installed.
Budget allowing, or if more than a portion of the fixtures required repair then a complete reballast to T8 is recommended to save energy and have a completely new system that should not require maintenance for a couple years.
If you have 8' lamped fixtures or your existing fixtures are in tough shape then you might want to consider changing to something like these:
http://www.acuitybrandslighting.com/library/ll/documents/specsheets/Gene ral%20Purpose%20Industrials.pdf
The 4 lamp tandem 8' fixture (4' lamps) is good bang for the buck and will give decent lighting for a shop. Choose 850 lamps (80% color rendering, 5000K color temp) and they will seem brighter to your eyes than cool whites.
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On Mon, 18 May 2009 10:25:59 -0500, Ignoramus24574

Charles has it right - you can buy replacement electronic ballasts that bolt up to the same fasteners, and change over to F32T8 as a drop-in. Be sure to label the fixture clearly so they use the right replacement lamps.
Eventually they want to discontinue T-12 lamps and magnetic ballasts totally. Get them out of the retail channel and make them 'wholesale house only' and I'll have to sign an affidavit to justify why I can't change the fixtiure over to electronic before they sell me one.
Change the whole strip if you can, since the reflectors really do help - plain strips waste a lot of light on the ceiling. "Shop Light" reflectors do help put the light down where you want it, and a good model costs about the same as a good replacement ballast.
Or better yet the new "T-5 Fluorescent Low-Bay" lights with individual reflectors on each lamp.
And the lamp color and Color Rendering Index (CRI) make a huge difference in a room. I run Spec50 lamps (5000K) with a 92 CRI where it matters, and cheap Cool White where it doesn't.
--<< Bruce >>--
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I bought 3 4' shop light fixtures from Home Depot and when I plugged them into a ground faulted line. They all tripped the ground fault. So I have them sitting in the box not being used.
Richard W.
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Richard W. wrote:

That's weird.
I wonder if the ballast is wired with 'neutral' swapped with 'ground'?
--Winston
--

Don't *faff*, dear.

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wrote:

If you plugged them into a GFCI protected receptacle and they tripped it, the light fixtures aren't necessarily bad - the normal Class A GFCI receptacle is overly sensitive looking for 3 milliamps of current imbalance and they trip.
If you paid less than $15 per fixture, it's very likely caused by a crappy "Lowest Bidder" electronic ballast. The cheap electronic ballasts that are not properly filtered can cause enough harmonics to fool the GFCI currrent sensor and trip it. Doesn't take much.
First thing is to plug the strips into a regular outlet and confirm that they do work. Then pop one open and see what the ballasts are and that they do have the polarities correct.
You might have to go back to HD and get the better shoplight fixtures, or run a seperate Non GFCI lighting circuit to the garage. Tap off the existing garage ceiling light fixture and extend the circuit with receptacles on the ceiling, that should be non GFCI.
Lights and dedicated appliance circuits (garage door opener, central vacuum, freezers and refrigeration equipment, low-voltage lighting transformers, sprinkler control timers) do not have to be GFCI protected, only the convenience receptacles. You can either run hardwired circuits to the appliances or place a single receptacle for them without a GFCI in most cases.
Please don't use a cube tap into one of these single outlets to run extension cords outside without a GFCI - they insist on them for a reason, people do get zapped and occasionally killed.
--<< Bruce >>--
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On Fri, 15 May 2009 23:34:14 -0700, Bruce L. Bergman

Some (a lot of) fluorescent lights will not light without grounding Gerry :-)} London, Canada
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Wes wrote:

I bought a number of dual-tube round fixtures, all of which failed at about the same time. Brainless at the time, spent 100 bucks on new tubes, still in darkness. Pulled one apart, electronic ballast, all the semis were blown, diodes included. Finally found an inductive one for about 3 bucks a copy, from maybe even sunpark, they work great and will tolerate what was probably a voltage spike from teh power grid. I can dig out the box if anyone wants the info... /mark
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For an extension to our building, I bought 17 Shop Light brand model 1233 fixtures from Home Depot. Some of these fixtures failed shortly after moving the ladder. These units kept failing so I contacted the mfr. and lo and behold they sent me free 17 complete new units. Guess what? Yep they failed almost faster than I could put them up. I informed the mfr. and told them please don't send me any more of those units even if they attached a $20 bill on each one. Since I had made my installation around the size of these units, I have been buying a better ballast and replacing the failed ballasts. I offered all the failed ballasts to Home Depot as I didn't want them; they didn't want them either. Along side of these failing units were some that are now 36 years old and require rare bulb changes only.
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The very cheapest dual 4' fluorescents have a simple inductor, a solid state "starter" to energize the filaments, and a capacitor - I've seen a plethora of these fail - for two reasons - shorts in the inductor and shorts in teh capacitor - particularly the cap. The capacitor is unprotected, just a roll of aluminum and mylar (or poly?), no outside cover - it absorbs moisture and it is subject to mechanical damage - another penny spent on a cover would have tripled the life, but of course that is a penny of lost profit - so, at a minimum I would avoid this type altogether.
The electronic versus inductive ballast issue is not clear cut - generally electronic ballasts are more efficient, but as some have pointed out, they are more fragile if there are significant power line voltage spikes.
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