# Retrofitting T12 to T8



## A Little Short

I've wired hundreds of ballasts before but haven't had to change over a T12 to T8 yet.
I've been searching some info on retrofitting them and I find conflicting instructions. Some say you only have to change the ballast and others say you have to replace the tombstones/sockets as well. Which is correct?
Also, if it's just 1 fixture, would it be cheaper to just replace the fixture. I haven't looked anywhere but Lowes for a fixture, but 80% of the reviews there said they were junk and the ballast didn't last long at all. Some said from a few months to just over a year.
Any particular brand of ballast better than others for the T8?


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## cultch

just change the ballast...sockets are ok. Easy to change ballast...pita to change fixture (realativily speaking)


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## Cletis

*Change*

Change

http://www.electriciantalk.com/f8/t12-t8-3872/


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## electricalwiz

you have to change the ballast, you can reuse the existing tombstones but they have to be rewired


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## noarcflash

I've done 100's of them. you need to change the wire configuration, by following the schematic on the ballast.

2 ballast come out, 1 goes in. They claim to be more energy efficent, but I have never seen a reduction in an electric bill, and I do ask everyone. They certainly throw off alot more light, so it is worth it.

Also, be prepared for failures. T8 ballast do fail very frequently. I had a major problem with Sylvania on a 100 ballast job. Every one failed, 1 by 1. I went ape-sh!t on Sylvania, and they sent in a crew with 100 new ballasts, and they did the whole job over while I watched.


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## sbrn33

That is crazy! If have not put in a T12 4 foot ballast in in 15 years. Why would you even think about putting in a T12. Hell t8's are almost outdated now, it's time to put in T5's


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## Edrick

sbrn33 said:


> That is crazy! If have not put in a T12 4 foot ballast in in 15 years. Why would you even think about putting in a T12. Hell t8's are almost outdated now, it's time to put in T5's


I think you confused yourself


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## electricalwiz

sbrn33 said:


> That is crazy! If have not put in a T12 4 foot ballast in in 15 years. Why would you even think about putting in a T12. Hell t8's are almost outdated now, it's time to put in T5's


 
the ROI is not there on T5 to justify the cost


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## Cletis

electricalwiz said:


> the ROI is not there on T5 to justify the cost


It isn't ? I just sold a 30 yr guarenteed ballast/10 year bulb t-8 system for 3x the initial cost for a large retrofit. It had a horrible ROI, but a fantastic lifetime real cost of light


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## gold

I just buy retro kits for the fixture Im doing, comes with tins tombstones and ballast. pre make the tombstones on the ground in the tins, one guy rips one guy hangs. We did about 70 stores for a franchise last year **fixtures* 120-150 stores / night converting 2 lamp 8' t12 to 4 lamp t8. Saving tombstones creates a headache you don't want over a buck.


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## roo24

we always reuse the tombstones unless their in rough shape. just have to rewire. takes about 15 min or less a fixture start to finish, including lamping. we use advance ballasts mostly cost about 15 bucks for a four bulb fixture and lamps range from 1.25 to 2.00 each depending on quality and color.


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## rdevarona

I agree with gold. Most of the guys we work with will order retrofit kits. We Have the ballasts wired to the new tomb stones at the factory to save time in the field. New tomb stones will help avoid troubleshooting time also, especially when changing out very old fixtures. 

The only thing to watch out for is when there are a lot of yellowed troffer lenses in offices. I think its more cost effective to replace the whole fixture in this case and make sure the customer is happy with a completely new look. 

Regards,

rdv


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## sbrn33

Eldric. I don't understand what you mean. I confused myself? How?


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## Runion Energy

I woundnt even use T-8 most of the older bulbs will be out-dated and phased out starting 4th quarter of this year. Led Tubes or Fixtures they way to go will be common in the very near future costs are dropping every year and in certains applications are cost effective solution.

P.Runion
Runion Energy Solutions


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## gecko

I just changed quite a few in the past week, and you can just change ballast, no need for rewiring fixture/sockets. You have 2 yellows/2 blues/and 2/reds on each end of fixture? If so, on your new ballast, take one yellow to each end and catch the yellows, then blues go to one end and reds to the other. One blue catches 2 reds and other blue catches 2 blues. Same thing at other end. Red to blues, then red to reds. Boom! Your done! Well, hope it doesn't go BOOM, but hope that is clear as mud. LOL if your setup is the same as all of them I've updated, then that will work


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## wildleg

gecko said:


> I just changed quite a few in the past week, and you can just change ballast, *no need for rewiring fixture/sockets*. You have 2 yellows/2 blues/and 2/reds on each end of fixture? If so, on your new ballast,_ take one yellow to each end and catch the yellows, then blues go to one end and reds to the other. One blue catches 2 reds and other blue catches 2 blues._ Same thing at other end. Red to blues, then red to reds. Boom! Your done! Well, hope it doesn't go BOOM, but hope that is clear as mud. LOL if your setup is the same as all of them I've updated, then that will work


*you don't need to rewire it*, _but you need to rewire it_.

that makes sense !


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## gecko

Sorry, I guess you call that re-wiring it. I just call it hooking up ballast. LOL one guy had me taking apart and change wires to tombstones to make them work, so that's what I think of. My bad, then YES, guess you have to "re-wire" it


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## wildleg

I've never used the retro kits, but I can see where that would be quick.


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## Cletis

*3 min*

should only take you 3 min 

http://www.youtube.com/watch?v=U4jAPAaksdo&feature=player_embedded


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## crosport

Use the proper t-8 shunted tombstones.If you do rewire the old ones make sure you keep the jumper between both sides as short as possible or you will shorten the life of the tube.Long jumpers on t-12 sockets cause breakdown of the tungsten particles on the filaments.(no I did'nt make this up!)Call any lighting manufacturer and they will recommend changing out the tombstones.


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## mnelectrician

There's quite a few ways you can retrofit troffers you can go 4 lamp t12 to 4 lamp t8s, 4 lamp t12s to 2 lamp t8s, 4 t12s lamp to 2 lamp t8 with reflectors. You can also tandem wire a 4 lamp t12 fixture where you have two lights running off of one 4 lamp ballast. We used to just change out the tombstones if we added a reflector and reuse the old ones if we didn't. Wouldn't hurt to change them they usually get cracked or brittle after a while from the heat coming off the lamps and ballasts. I used to retrofit at night about 11 years ago. Made for some kinda long days after working all day.


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## Electric_Light

Cletis said:


> I just sold a 30 yr guarenteed


Sure, just send them back to us freight prepaid along with a check for $5.95/ballast for handling and return shipping. We'll also send you a $10 off brake work with purchase of lifetime brake pads from our partner shop.


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