Lighting problem sanity check

[Anonymous]

I have two T12 96" two bulb fluorescent lights that are causing me problems. One of them is out, then its on, then its out. This happens several times a day. The other one seems to be dimmer than all the others in the store. Do both of these units need new ballasts, or could there be something else?

As for ballasts, what type of savings should one expect with an electronic versus a magnetic ballast. The existing ones are all magnetic. I saw them at HomeDepot and the magnetic ones are $19 while the electronics are $33. Does it make sense to go electronic? How much will they save in electricity?

[ferd]

I found out the hard way that you should change both bulbs when only one looks bad. Had a situation very similar to yours. Changed both bulbs and the trouble went away!

[pete f]

Sometime after the 4 hurricanes this summer my outside lights under the canopies acted up. I had to wack them with a broom to make them light, same lights you have. I took them apart,. cleaned ends, fixtures, etc. still had trouble. I bought new fixtures for $35 each and replaced them a few weeks ago, problem solved. Only so much time in a day to mess with it. If you got bulbs coming on and going off, it seems to be the same sort of problem. If a ballaset goes, the light go with it, as a rule. If a bulb goes out, the other will go out with it, or be very weak.

[CharlieS]

I have replaced most of my ballast in one mat with electronic, plus all of the lights in my other mats with new fixtures that have electronic T8.

There is supposed to be a savings, but I don't have baseline data to show it one way or the other. However, there is one major benefit to electronic. Unlike magnetic, each bulb runs independently. If one goes out, the good bulb(s) keeps operating. No more guessing which bulbs are good or bad.

Charlie

[Anonymous]

Do they get really hot like the old style ones?

[Anonymous]

If I keep the T12 bulbs, as I don't want to replace the fixtures - too much work--- what energy savings can I expect if I swap out all the magnetic ballasts for electronic ones?

Answered my own question. Went to www.universalballast.com and downloaded a little program that calculates savings. It appears that I could save about $20 a year on electricity for each fixture (2 T12-60 Watt bulbs). Since the ballasts cost $33 each plus my time to change them I don't think I will do it proactively. But as ballasts die I will replace them with the $33 electronic versus the $19 magnetic.

[MichaelCa]

Kirby, i just finished changing a boatload of Magenetic Ballasts to Electronic Ballasts :

You must have 8 ft. long bulbs/fixture. Assuming that, the cost @ Home Depot for this Electronic Ballast is $ 26. It is $ 16 for the 4ft ballast.
The new T8 (i'm referring to the low watt version -there are 2 levels of wattage for each size of bulb, aside from other considerations)actually puts out more light than the T12.
One thing you want to make sure when you buy new T8 bulbs, is to buy the kind that have a "CRI" of 84 OR HIGHER. (CRI: Color Rendition Index) The old T12's have 78 or lower.
This does not cost you any more in wattage/energy - it is just a more efficient light output. Another factor to compare, is the "Lumens" output for a new proposed T8 vs. your old T12 - that is a direct measure of light output. Lumens replaces the old term 'footcandles'.

I just finished doing all in my mat .... So was it worth it ? HELL YES.

Even if the savings turn out to be minimal, it looks a LOT brighter; The bulbs are cool to the touch; They last years longer; It is a uniform & clean look (compared to the patchwork of half-dying T12's)

Dont let the maze of numbers out there confuse you.
Just apply the above logic of Lumens & CRI, and you'll be fine.

Oh, btw, there is also a thing called Color Temparature (called Kelvins)
6500 is an Arctic-blueish-white light, 5000 is medium blue-white, 4100 is neutral, 3500 is warmish sunny glow, 3000 is almost pinkish warm glow (like incandescent).
Most Mats will do well with 5000.

[Anonymous]

I always thought HomeDepot and other national chains had uniform pricing (except for Hawaii and Alaska). I bought one of those ballasts yesterday and it cost $33 at HomeDepot here in NJ. So, either they don't have uniform pricing - or the price has gone up.

You are correct, the T12's that I have are 8'. I thought about changing the fixtures and going with T8's but they only come in 4' lengths and that would be a lot of work to change all the fixtures. I don't think I want to get into that, as I would probably have to replace the ceiling tiles as well as I am sure things would not line up the same as now and am sure they have faded. Not looking to create a bunch of extra work and expense.

How much do you think the T8's will save compared to the T12's?

[pete f]

Home Depot does not sell the T-8's in 8' fixtures. I go to a local electric supply house. I went to Grainger for the previous ones I posted, and I wanted the t-8's, but they were out and I was tired of messing with the old fixtures. The T-8 fixtures cost about $60 vs the $35 and I would have rather bought them. As for savings, yes, I believe you will get your money back within a couple years. I re-do an older mat with new T-8 fixtures, 4' ft ones, and dropped the electric bill $50 a month. I had 4 light T-12's, dropped to 2 light T-8's, BUT most of the fixtures were only running 2 lights, not 4. I did my newest mat in T-8's. It is a no brainer, as D. Trump likes to say on his show. Also, I found it cheaper to just buy the new fixture than try and rewire the old T-12's to the new T-8's, to much time involved, plus new fixtures look nice..

[Anonymous]

Also, when it's time to sell, that $50/month savings is worth $1800 - $3,000 extra in sales price. Good payback there too.

[Anonymous]

Just went to the local electrical supply house, and they have the T8 bulbs in 8' lengths that would be compatible with existing fixtures - would just have to change the ballasts.

It is interesting they sell the electronic ballasts for the T12 for $38.25, but the electronic to convert to the T8 is $32.15, plus the bulbs are $7.65/ea. So the question then becomes if I spend the (32.15 + 7.65 +7.65) $47.45 per fixture to convert the ballasts and bulbs to T8 how much money will I save on electricity?

Guess I need to search some more on what savings the T8 offer.

[Gary C]

Your thinking too much it's making my head hurt.:) If the lighting will be better just do it.

Gary

[MichaelCa]

Fer 'eavens sake, Kirby - I thought you were the scientific brain on this board :)

OK, i'll supply the numbers, you do the math (or get Pete to do it for you) :

*Advance Transformer (Ballast Mfr.) Specs*
Magnetic Ballast 8ft T12 (2 per fixture) Ratings:
- NW: 75 (per bulb) -AW: 144 - Amps: 1.24

Magnetic Ballast 8ft T12 Ratings (when used w/"Energy Saver" bulbs)
- NW: 60 (per bulb) -AW: 126 - Amps: 1.1

Electronic Ballast 8ft T8 Ratings:
- NW: 59 (per bulb) -AW: 110 - Amps: 0.94

As you can see, even if you are already using the now common "Energy saver" T12 bulbs, despite the seemingly little difference in bulb watts of only 1 watt, you save 15% on total Amps used , because the Magnetic Ballasts are ENERGY HOGS.
And, as I mentioned before, you will get *MORE* light from the new T8 bulb. Not to mention a doubling of lifespan.

Re: 'more light' ...i calculated on 4ft's, that every 4 T8's put out the same light as 5 T12. Again, if your brain forces you to do calcs, just tally up the Lumens ratings per bulb on both types.

You'll also need to amortize the cost of 12-16,000 hrs, vs. 24-30,000 hrs of T8's. (Lifespan) Roughly 2.5 vs. 5 years.

Did i mention there's no more 'noise/hum' ?

BTW, as for swapping out fixtures, changing Ballasts was much easier/faster (for 4fts). And slightly cheaper. On a 'dropped' ceiling you have a whole mess of steel tabs and hanging guy wires to deal with, not to mention the prospect of re-crimping #12 power wires inside every single j-box.
Ballasts are simply held by 2 screws, and you're only re-crimping very skinny wires - plus there's no j-box to mess with.

------------
Finally, here's the Home Depot Ballast SKU # 781087048856, $26.26 ea.
Model #REL-2P59-S-RH-TP

[Gary C]

That was well explained. Thanks

Gary

[Anonymous]

I have found electronic ballasts to have a higher failure rate. Buy some extras you will need them.

[Anonymous]

OK, here is what I have found. The T12 magnetic ballast with 60W bulbs draws 1.16amps while the T12 electronic ballast with 60W bulbs draws 0.93 amps which is just about the same as what you were saying the T8 ballast and bulb draws (0.94). I understand that the T8 puts out 10-15% more light, but since I don't need more light that is not an issue. What this tells me is that there is no real advantage going to the T8 as opposed to just upgrading tha ballasts. BUT......

at 120 VAC that only comes out to a savings of about 18watts per fixture per hour. If we assume 18 hours a day, 360 days a year with electricity at about 11 cents per kwh that comes out to an annual savings of $12.83. Since the ballasts cost about $34 plus tax we are talking about a payback of roughly 3 years.

[Rondo]

Kirby, you need to figure in the cost of not replacing bulbs as a factor too. I replaced all my ballasts 3 1/2 years ago in one store and to this day I have not replaced one bulb (T8). Before the upgrade I had to buy a case of T12s every 6 months and we were constantly replacing bulbs.

[Anonymous]

Sounds like you had some other problem going on that you were replacing the T12s that fast. They should last at least 12,000 hours. Even if you have them on for 24 hours a day, that would be 500 days they should last.

[Rondo]

I had 4 ft lay in 4 bulb fixtures... 2 very hot magnetic ballasts, ceiling height 8'. The heat that came off the fixtures was intense. Changed to one electronic ballast - 2 bulb and saves a load of electricity and reduced the load on my AC in the summer.

BTW, the light output was about the same

One more tip, If you have 8' 2 bulb fixtures you can change the sockets to a one bulb per fixture and only put one ballast (electronic) per 2 fixtures and get about the same light. This is easy to do if your fixtures are all channeled together in rows. This really saves wattage.