I bought an inexpensive 4' T8 dual tube light at home depot, they still sell it,
with an electronic ballast. Well, it crapped out a couple days ago, actually
flaky as in sensitive to temperature for a couple weeks. It lived a week short
I ripped it apart, ohmed out the pre heat filaments in tubes and googled the
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
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
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
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
start the light. That simplistic wiring diagram was giving me pause.
I learned something today.
replacements had me
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,
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.
one used the
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.
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.
replacements had me
found a GE
light I have is
one used the
two tubes have
be heated to
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...
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.
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?
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.
Ignoramus24574 wrote in
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
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
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:
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, 5000ºK color temp) and they will seem brighter to your eyes
than cool whites.
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
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.