OT T8 Tubes

[woodchucker]

I am having a problem with some T8's that I bought from HD. They are Phillips Altos.

I have two boxes, of 10 one is daylight, one is for home and office (not sure of K).

Anyway they keep burning out in 3 months. I have tried replacing the ballast, I have tried other fixtures, I started dating them in marker on the bulbs.

They never are great, when they come on they are bright, but over a few minutes they get darker and zebra lines (best way to describe the pulsing) start appearing.

Any idea why this is happening? What would make one brand of tube behave so poorly?

[Mike Marlow]

Hope we get some good answers to this Jeff, because I've had bad luck with the T8's I get at the depot too. An election friend told me it may be because they get turned on an off too much - they really prefer to stay on for long periods of time.

[ads]

They once advertised the life of fluorescent tubes as "xxxx hours, less three hours per start" so apparently leaving them on is better than turning them off when you go to lunch.

The alternative is to get LED replacement "tubes" and rewire the fixtures *unless* they are electronic ballast. OK if you're the electrician, expensive if you hire it done. The fixtures in my basement are older T12 so would require rewiring. The LED tubes use about half the power for the same number of lumens and they have a predicted 50,000 hour life.

Example electronic ballast compatible tube here (it's a long URL so watch for wrap on some newsreaders):

These are $9 per tube in single quantity (includes shipping). That drops to $8 per tube if you buy 25 or more.

If you get 10 times the life of a fluorescent from the LED tube, then you'd be way ahead on the total cost of the tubes.

[John McCoy]

Mike Marlow wrote in news:nfdn2i$rih$ [e-mail]:

Sounds like the wrong kind of ballast. T8's need a T8 ballast, and by that I mean a ballast for T8 only. The ballasts that claim to work with both T8 and T12 bulbs generally don't work well with T8s (this tends to directly correlate to the cost of the ballast - there are good electronic ballasts, but the cheap ones at HD/Lowes are a crapshoot).

I hate the T8 bulbs - the idiot that decided they should use the same 2-pin base as T12s should be shot. I can't count the number of cases I know of where T8 ballasts have been fried by people putting T12 bulbs in, because they fit and there's absolutely nothing on the fixture to say don't use them.

(to Mike's question, all flourescent bulbs don't like being turned on & off, not just T8s. But the T8's seem much more persnickety about the ballast they're used with).

John

[Meanie]

Best advice thus far.

Where are the lights being used? Are they constantly turned on and off? As John said, are you using the proper T8 only ballast? In addition to ballasts, is it Instant start, rapid start or program start? The type makes all the difference in the world depending on where it's used. In a constant on/off environment, you want program start. If the lights stay on throughout the day, you want instant start. Don't buy the cheap home depot ballasts. Pay a little more for something like Philips Advance ballasts.

Many of the new Alto bulbs offer and average of 40,000 hours but newer Altos offer a 60,000 to 80,000 hour range but cost much more. Though, all that is meaningless if you use the wrong ballast.

[Mike Marlow]

My fixtures are now all T8 fixtures. Don't know the ballast details. I use only Altos bulbs. My lights can get turned on/off several times per day depending on what I'm doing.

[Ed Pawlowski]

Let's see if I understand this. You hate T8 bulbs because idiots put T12 bulbs in the fixtures? I like them because I can put in a T8 ballast when the old fixtures die and upgrade them.

In our shop we replaced all the fixtures with T8 in 2008. We are starting to replace many of the bulbs as they are stating to die with about 100,000 hours on them. They typically are turned on once a day for 10 hours

[Just Wondering]

[Ed Pawlowski]

Yeah, but I got more clicks on the calculator.

[ChairMan]

Stop buying them at HD. I have a friend that is an electrican and he told me, like Walmart, HD tells suppliers what they will pay. The manufacturers have to figure out how to make them cheap enough for HD. Which means they put less gas in them, thinner glass for the bulb and any other thing they can do to make it cheap enough. He picks them up a the supply house for me now and they last much longer than the ones I use to get at HD. YMMV

[John McCoy]

Ed Pawlowski wrote in news:_7ydnSuYLPq3NYfKnZ2dnUU7- [e-mail]:

Understand, I'm an engineer. I've spent 30 years designing things to be as idiot-proof as possible, and one aspect of that is, you don't use the same pinout for things unless they are 100% compatible.

T8 and T12 bulbs are not interchangeable. Having the same pinout is bad engineering, plain and simple.

BTW, changing the sockets when you change the ballast is trivially simple.

Round about that same time I replaced the couple of T8 fixtures I had with T12 ballasts. They're more reliable, brighter, and last longer, and I figure by the time I'm out of T12 bulbs LEDs will be cheap enough to be an economical replacement (I use the same thinking with Edison base bulbs - after trying a couple of twisties, I'm sticking with incandescents until the LED prices are low enough to make switching make sense).

John

[Brewster]

your-fluorescent-t8-t10-t12-lamps-with-led/products/luceco-led-

fluorescent-replacement-tube-generation-2-4-ft-15-watt-t8-ballast-

compatible-full-glass-body?variant=13929341956&mc_cid=f02a49d337&mc_eid=5bdd20d24e

I went with these in the 6 (4' x 4-tube) troffers I have in the shop. The power/lumens is about the same as fluorescent tubes, but the light stays bright as they age and that infernal buzzing is finally gone! Since they direct light in only one direction (down) instead of 360 degrees, they seem brighter.

I just went ahead an bypassed my ballasts, no need to generate excess heat.

-BR

[Mike Marlow]

Well... not so much John. There are fixtures that are rated for either T8 or T12. That makes the common pin out logical.

Yes, it is.

[krw]

It's possible to design a connector that will take only T12 (old connector), only T8 or either. That should have been the goal.

It costs an extra $1.50 (perhaps a big deal for institutions with thousand) and some are riveted so not so trivial.

[woodchucker]

These are all t8 ballasts. The shop has 3 bulb T8 dropped ceiling units, (originally made for T8). The others have all been replaced with T8 Ballasts Ge Units. I had to rewire and jumper the tombestones for T8 and wire correctly.

[Swingman]

That's my experience.

Never turn my shop T-8's off ... on 24/7. Only time they go off is if the power goes out, or the rare times I've needed to do some electrical work.

Have probably replaced three of the ten bulbs in the five fixtures in 15 years.

[Puckdropper]

krw wrote in news:bm3nhbl2k8c4es4cuh9f2ke2d9752kplov@

4ax.com:

*snip*

If you buy good drill bits or can sharpen yours...

Right, not so trivial.

Moving on...

Puckdropper

[dadiOH]

A problem I've experienced with LEDs...

Late last fall I installed four, flush mount ceiling fixtures with integral LED; i.e., the bulb was built in...when it burned out, toss the whole fixture. Within about 4 months, two of the four started flickering; a very annoying flicker, maybe 25 cycles or a bit less per second.

Web research told me that LEDs are very susceptible to voltage variation and that a poor switch could cause the problem. Each flickering light had its own switch; each was on a separate circuit. I figured my best bet was to toss them and replace with incandescent. Which I just did.

[krw]

That's easy for homeowners but not so easy for commercial installations. You don't think they design this stuff for us?

[Leon]

Maybe the ballasts. I have the same brand, daylight, and all 16 in my garage are over 5 years old. I have nor replaced any but have replaced 1 ballast. .