T8's vs T12's

[Jim Eller]

If a fluorescent fixture has T-12 tubes in it, can they be replaced with T-8's or visa versa? Will the ballast handle either? Are the pins the same?

Or what do you need to do to change?

Thanks,
Jim

[Rollie Meyers]

If the ballast is rated for T12 lamps you must use T12 lamps, the use of T8 lamps w/o a ballast swap out will result in extremely short lamp life & possible ballast damage, BTW the ballasts common on older T12 gear are due to be phased out soon (think it's in 2010) in favor of electronic ballasts.

[Russ Boyd]

.....and the tubes (and pins) are different sizes.

[Jim Eller]

Thanks Rollie and Russ(I like the sound of that. One more "R" name and it would sound like a gaggle of attorneys).

I figured it was too easy.

The reason I asked was I just purchased a bunch on 4-tube used lights for the shop and some on the tubes will need to be replaced for sure. I thought I would "upgrade" if possible.

Oh well.........

Jim

[David G Baker]

Jim,
I made the mistake three years ago buying $500 worth of T12s for my pole barn. They work okay but they buzz like a hive of bees. I knew about the T8s but the price was too good to pass up on the T12s. Me and my going on the cheap haunts me on occasion.

[Robert Parrish]

I added 32 T8's to my shop but I made the mistake of leaving the old T12's connected which were on another circuit. The T12's buzz non stop and give off half the light. I will probably replace them this spring.

[Jim Eller]

Well, if they don't workout they were only ten bucks each so it would be a cheap lesson. They are four tube with swing down light defusing panel so I'm sure I can get my ten bucks back. They are in really good looking condition and most have all four tubes in them.

I currently have six two tube lights(T-12) in the shop now and for whatever reason, they don't hum/buzz or bother the tv.

Jim

[Rollie Meyers]

.....and the tubes (and pins) are different sizes.


Pin spacing is the same on F40T12 & FO32T8 lamps (med bipin). They retrofit quite well.

[Brad Sperr]

It's really easy to swap out ballasts (wiring diagrams are right on front). Just make sure the new T8 ballasts you get will support four lamps.

[Jim Eller]

OK Rollie, now I'm confused.

"They retrofit quite well"????

What did I miss? Do you mean after you change the ballast?

How can you tell if the ballast you have will support T-8's?

Jim

[Ed Hazel]

I recently put 6 8ft t12HO lights in my garage I think they are great they put out lots of light. They are only on when I am working in the garage which is not that often, only when I am working on cars. I wanted a light that would always turn on despite the temp and produces a lot of light. These are the newer ones with electronic ballasts they do not hum.

[Rollie Meyers]

OK Rollie, now I'm confused.

"They retrofit quite well"????

What did I miss? Do you mean after you change the ballast?

How can you tell if the ballast you have will support T-8's?

Jim

Maybe I should have given a bit more info, a retrofit means replacing the lamps, ballast(s) and sometimes even adding reflectors to be able to remove 1 or more lamps to further reduce power consumption. The ballast of of the existing fixture should have the data on the label but if it fell off then it's a educated guess of what it's designed to use.

[Jim Eller]

Rollie,

Here is what is says on the ballasts(2 each):

Advance Transformer Co.

Cat. No RQM-2S40-3-TP

For 2-F40 48" 40W 430ma Rapid Start
or 2-F40 48" 34W or 35W 460ma Rapid Start Lamps

Class "P" Type 1

If these don't work, what would you replace them with? Please be specific.

Jim

[Rollie Meyers]

The ballast is for F40T12 lamps or the currently avail. reduced wattage lamps since a large number of lamps were pulled from the market due to energy regs. if you need to replace them, then I would retrofit them for T8's then the price for T8 lamps has dropped & electronic ballasts are not all that bad now the price difference is close enough to make it a no brainer.

Note: I do not have specific catalog #'s on hand to post but if needed could find them.

[Jim Eller]

Where would one start looking for ballast for the T-8's? .........at a reasonable price of course. Are they all the same?? Can you get one ballast to run four tubes?(currently there are two)

Thanks,
Jim

[Chris Padilla]

Home Depot has very good prices on T8 bulbs, fixtures, and ballasts so start there.

[glenn bradley]

Where would one start looking for ballast for the T-8's? .........at a reasonable price of course. Are they all the same?? Can you get one ballast to run four tubes?(currently there are two)

Thanks,
Jim

I went down this road. All I found was that the ballast was 90% of the cost of a new fixture. Hopefully someone here knows of a supplier for you but I couldn't find them in my area. When I did find them at an "almost worth the effort" price outside my area, the shipping killed the deal.

Most of my T-12's went to LOML's garage for her laundry area and general lighting there. The last of my T-12's will go cheap at the next garage sale.

Oh, and just a side by side comparison opinion . .. WOW, what a difference.

[Jim Eller]

Well, I looked here, http://www.ballastwise.com/category.asp?FID=13&level=1 and here, http://www.lightmart.com/index.asp?PageAction=VIEWCATS&Category=2524 and that confuses the issue.

I would guess I'm looking for a four lamp ballast for T8's but there are more than one listed.

Any idea what the differences are or what I really need?

Jim

[Rollie Meyers]

Where would one start looking for ballast for the T-8's? .........at a reasonable price of course. Are they all the same?? Can you get one ballast to run four tubes?(currently there are two)

Thanks,
Jim

They are avail. from the big box stores, (Home Despot & Blowes) I had bought some Advance 120 V 4 lamp ballasts (REL-4P32-SC) at HD & had trouble w/ all 4 of them which soured me on buying them at a big box VS a legit electrical distributor because warranty issues are usually taken care of by the supply house. 3 were replaced by the same, 1 was replaced by a multi-volt (120-277V) Sylvania ballast, so am watching that one. Lowes has a Advance Centium multi-volt ballast at a higher price....

BTW Electronic ballasts do wire differantly then what you are replacing follow the wiring diagram & you will have no problems.

[Rod Sheridan]

Over the last 4 years we've replaced thousands of T12 magnetic ballasts with the following Sylvania T8 electronic ballasts;

2 lamp QTP2X32T8/UNV-ISN-SC

4 lamp QTP4X32T8/UNV-ISN-SC

I think we've experienced 3 or 4 failures since the ballasts have been replaced.

Most of our ballasts would be on continuously for that time, aproximately 10% would be intermittent operation.

Regards, Rod.

[Craig Summers]

Over the last 4 years we've replaced thousands of T12 magnetic ballasts with the following Sylvania T8 electronic ballasts;

Regards, Rod.

And just how big is your shop? :D

I can see the glow from here, we used to call that the Northern Lights

[Rod Sheridan]

And just how big is your shop? :D

I can see the glow from here, we used to call that the Northern Lights

That's pretty funny Craig.

However my shop isn't big enough to store that many ballasts, forget about installing them!

Regards, Rod.

[Chris Padilla]

They are avail. from the big box stores, (Home Despot & Blowes) I had bought some Advance 120 V 4 lamp ballasts (REL-4P32-SC) at HD & had trouble w/ all 4 of them which soured me on buying them at a big box VS a legit electrical distributor because warranty issues are usually taken care of by the supply house. 3 were replaced by the same, 1 was replaced by a multi-volt (120-277V) Sylvania ballast, so am watching that one. Lowes has a Advance Centium multi-volt ballast at a higher price....

BTW Electronic ballasts do wire differantly then what you are replacing follow the wiring diagram & you will have no problems.

So far so good with the T8 fixtures and bulbs I've gotten at HD. I'm 3 years into them for the shop and just replaced the T12s in my kitchen with the very same kind I have in my garage.

Oh, 1 T8 of the 28 T8s I have in my garage finally died the other day. Not too shabby, me thinks....

[Jim Eller]

I looked at HD and Lowe's today. They want about $30 for four lamp T8 ballast. It's about half of that at internet site.

Any one have an internet source they have dealt with and trust?

Here is one example: http://www.atlantalightbulbs.com/ecart/10Expand.asp?ProductCode=QTP4X32T8.UNV-ISN-SC

Some go as low as $14, but................. what is the difference between these units. There are many by the same manufacture that say they are for four lamp T8's but have different model numbers.

What are the guidelines to look for when purchasing?

I realize I'm being tutored but I sure do appreciate the education.

Jim

[Chris Padilla]

Jim,

Looking at your link, for $20 & shipping, you don't get the housing. I don't recall the exact prices at Home Depot, but I picked up an entire fixture (housing and ballast, whole 9 yards) for between $30-40 for an 8' light (4 4' T8 bulbs). If anything is wrong with the ballast/housing, very simple to take it back. So far, what I've bought is working just peachy.

[Michael Wetzel]

.....and the tubes (and pins) are different sizes.

Unfortunately that is not true. T8 and T12 have the same tombstones. A few of my staff at work have managed to put the wrong bulbs in various fixtures since we use both. You can retrofit a t12 fixture by changing only the ballast. This is assuming you are talking about the standard 2 pin fixtures.

[David G Baker]

Michael,
I just pulled a 4 bulb T-12 unit and replaced it with a 4 bulb T-8 unit, there is absolutely no way the bulbs could be interchanged. The spacing between the pins is very different. There may have been some changes that I don't know about. There may be large T-8 bulbs that have the same tube size as the T-12s that I am not familiar with.

[Rollie Meyers]

Michael,
I just pulled a 4 bulb T-12 unit and replaced it with a 4 bulb T-8 unit, there is absolutely no way the bulbs could be interchanged. The spacing between the pins is very different. There may have been some changes that I don't know about. There may be large T-8 bulbs that have the same tube size as the T-12s that I am not familiar with.

T8 & T12 have the same med bi-pin ends, only difference is the diameter of the lamps as they are measured in 1/8" increments so a 8/8ths lamp is 1" and a 12/8ths is 1 1/2" ... Oh and the lampholders are the same.

[Michael Wetzel]

Michael,
I just pulled a 4 bulb T-12 unit and replaced it with a 4 bulb T-8 unit, there is absolutely no way the bulbs could be interchanged. The spacing between the pins is very different. There may have been some changes that I don't know about. There may be large T-8 bulbs that have the same tube size as the T-12s that I am not familiar with.

It is an optical illusion. The pins are exactly the same spacing and size. The only difference is the tube and metal cap is bigger on the T12.

I went to a couple of seminars in lighting upgrades in order to save money by relamping buildings. The recommendation for 4' t12 fixtures is to replace the ballasts with t8 ballasts. You do not have to change the tombstones to go to t8. If you go to t5, you must change the ballast AND tombstones.

[David G Baker]

I do have optical issues. The pins sure did look smaller. Ya learn something new every day. Thanks for the education. :o

[John Fricke]

You can buy ballasts at the Borgs. I really like the Daylight bulbs. Lots of Bright white light. I'm not 100% sure but I think most of the new electronic ballasts are rated for T12 and T8. Anybody dissatified with their lighting should try a set of the daylight bulbs. Look for the kelvin rating. go for 5500 or higher.

[Rollie Meyers]

You can buy ballasts at the Borgs. I really like the Daylight bulbs. Lots of Bright white light. I'm not 100% sure but I think most of the new electronic ballasts are rated for T12 and T8. Anybody dissatified with their lighting should try a set of the daylight bulbs. Look for the kelvin rating. go for 5500 or higher.


A ballast will not work w/ T8 and T12 lamps they are designed for one or the other but not both, mixing them up will result in short lamp life or ballast damage.

[Jeffrey Makiel]

Some of the newer fixtures in my home shop say that they can use either T-8 or T-12. Right now, I using T-12 bulbs in them. I never tried T-8 bulbs in them, but I assume the end caps are designed as to accept both pin widths.

-Jeff :)

[John Baranowski]

I too have fixtures in which the ballast claims to be rated for both T-8 and T-12. Bought from Lowe's

[Chris Padilla]

The most significant item I've noticed when comparing T8s to T12s is noise. The T8s do not buzz...at all....