Somebody school me on fluorescent lamps and ballasts

[BatteryCharger]

I'm moving into a new workshop and it is lit with 8' T12 fluorescent lights. They've got the old magnetic ballasts and they sound like a swarm of bees when they're on. I want to replace the ballasts with new electronic ones.

But then I got to thinking, I might as well switch from T12 to T8 while I'm doing that. I'd also kind rather use 4' tubes instead of 8', a lot easier for me to deal with and not break. I saw 8' T8 tubes for sale at Home Depot, but I couldn't find any 8' T8 ballasts.

Anyway, a couple questions:
Do T8 bi pin bulbs fit in the same socket as T12 bulbs?
Are 8' tubes more efficient than 4' tubes?
Is there any other reason to keep the T12 over the T8, or the 8' instead of 4'?

 

[TorchBoy]

Eight foot long fluoro tubes?

 

[Lynx_Arc]

Eight foot long fluoro tubes?

yup..... F96T12 used to be all over the place in businesses and stores

 

[blasterman]

Still are all over the place. While not cheaper per lumen, 8footers are cheaper per linear foot of coverage. Always wanted to buy a crate and stick them in the ground around high voltage transmission lines and call it performance art or something

Pretty much everybody on the planet has migrated to 4-foot T5 and T8. And yeah, there's a big jump in efficiency going from T12 to T8, although a lot of this is due to the slimmer tubes not blocking as much light (strikeback) and WAY better electronic ballasts.

T5 are the bees-knees right now, but their biggest advantage is they are slimmer so more can be crammed into a small space.

 

[Lynx_Arc]

I have some 4 foot T12 lights in my garage. If I were using them every day I would consider going to T5s but I may put 4 hours on them in a week which wont save me the price of replacing them over the next 5 years in use.

 

[TorchBoy]

Wow. You Americans really do do things bigger. I can imagine they're quite a thing to handle - the amount of torque you could build up with a gentle swing...

 

[Scott Packard]

8' T12 and T8 are not that common around the house, so maybe that's why you didn't find a ballast at The Home Depot for them. You could try their special order desk. Also, in large cities there's a different "Contractor" THD that stocks more supplies for commercial applications.

 

[jtr1962]

Wow. You Americans really do do things bigger. I can imagine they're quite a thing to handle - the amount of torque you could build up with a gentle swing...

I vaguely remember 16 foot tubes being made also but I can't find a link. IIRC they were mostly used on railway coaches.

 

[broadgage]

I vaguely remember 16 foot tubes being made also but I can't find a link. IIRC they were mostly used on railway coaches.

I have never heard of a 16 foot flourescent lamp and think that you may be mistaken re this.
The 8 foot ones are bad enough to handle !

Here in the UK 8 foot tubes used to be very popular and are still used to a limited extent, but are not much installed now.

The original 8 foot tubes were 125 watts, these used a series choke and capacitor circuit with a glow starter, or less commonly a transformer ballast.
Then in the 1970s an energy saving 8 foot 100 watt tube was introduced, to work in the same fittings, and give slightly less light for significantly less power.
Then manufacturers introduced new ballasts that were optimised for 100 watt lamps and would not reliably work the 125 watt ones.
There was also an 8 foot 85 watt lamp that was not interchangeable with either the 100 watt or 125 watt versions.
All had standard bi pin caps and were T12.

A big drawback of 8 foot tubes was that the voltage across the tube was a large fraction of the mains voltage, with a relatively low voltage accross the choke.
Any reduction in the mains voltage resulted in a noticeably dimmer light, poor starting and flickering.
A 240 volt supply was the abosulte minimum, such circuits would not work reliably on 220 volts.
One could of course use a much lower supply voltage such as 120 volts, by useing a transformer ballast, but that was not common owing to the increased costs and losses.

The modern tendancy is to use electronic ballasts, and AFAIK these are not manufactured for 8 foot lamps.

 

[jtr1962]

I have never heard of a 16 foot flourescent lamp and think that you may be mistaken re this.
The 8 foot ones are bad enough to handle !

When I say vaguely remember, I mean vaguely remember as in when I was a kid around 40 years ago from something I either read or watched on TV or was told by my teachers. Given that I couldn't find a link, if they were made at all, then they haven't been made for probably at least 30 years. All kinds of strange things were made 30 or 40 years ago which today we can't fathom why they were ever made.

The modern tendancy is to use electronic ballasts, and AFAIK these are not manufactured for 8 foot lamps.

F96T12 electronic ballast

 

[broadgage]

Interesting to see that electronic ballasts for 8 foot lamps are available in the USA.
Dont seem to be available in the UK though.

 

[jerry i h]

Those 8-footers are a royal pain-in-the-u-know-what to change. We have
'em at work, and it is a 2 person job. Before you decide, check on the prices of T12, T8, and button replacement tubes in your area. I have discovered a rather dramatic difference in $.

 

[BatteryCharger]

Well, I decided I'm going to have to go with 4' T8 tubes and electronic ballasts. Guess what I found in the attic? A FULL CASE of brand new 32w GE T8s. Sweet!

I'm just going to leave the old 8' buzzers on the ceiling and add as much T8 along side them as there is now. Then, if I want extra light now and then I can use the old ones too. (and frankly I don't want to figure out how to get rid of about 20 8' tubes)

 

[PhotonWrangler]

Well, I decided I'm going to have to go with 4' T8 tubes and electronic ballasts. Guess what I found in the attic? A FULL CASE of brand new 32w GE T8s. Sweet!

I'm just going to leave the old 8' buzzers on the ceiling and add as much T8 along side them as there is now. Then, if I want extra light now and then I can use the old ones too. (and frankly I don't want to figure out how to get rid of about 20 8' tubes)

Good call on moving to 4' tubes. The 8' tubes are sooo oeasy to break, then you have little blobs of mercury sitting around on the floor. If any of that mercury winds up sitting in front of a heating vent, you wind up with a situation that could require moon suits to clean up.

Electronic ballasts produce bright, flicker-free light. It's much easier on the eyes for extended reading. I will never install a magnetic ballast again just for this reason. energy savings aside.

 

[BatteryCharger]

Ok, I said I was just going to leave the old 8's there as backup, but the light geek in me still wants more...

Since the fixtures are already installed, and will be used for secondary lighting, what is the brightest 8' T12 bulb I can buy? What's the max wattage? Mine are kind of random, some say 60w, some say 100w, some say nothing. I'll probably buy a case of something.

The shop across the parking lot from mine does commercial lighting and I think I can get them to take my old bulbs for free/cheap. They must dispose of them on a regular basis. He also might be able to order me a box of bulbs for cheap. (and he wants me to hookup an outlet for him on my building )

Or then again I could stack the old ones in the attic and forget about them. LOL

 

[Random Guy]

There are alot of different types of F 96T12. There is normal, High Output, and Very High Output. There are also Watt-Miser versions of all those. Go look at your lamps. If they are normal output, they should say something like F96T12/CW. If they are High Output or Very High Output, they should have a HO or VHO somewhere. You cannot put normal output lamps in a HO fixture & vice-versa. Same goes for VHO lamps and fixtures, but those are pretty uncommon.

 

[BatteryCharger]

Hmmm, looks like the few I looked at before were the few odd balls - most of the 8' tubes are 110w Philips Alto 8800 lumens like these:
http://www.1000bulbs.com/F96T12-High-Output/982/

That's 4400 lumens per 4', I can't beat that with any T8, can I?

 

[Random Guy]

Hmmm, looks like the few I looked at before were the few odd balls - most of the 8' tubes are 110w Philips Alto 8800 lumens like these:
http://www.1000bulbs.com/F96T12-High-Output/982/

That's 4400 lumens per 4', I can't beat that with any T8, can I?

You have F96T12/HO lamps then. What you need to beat that with a T8 is (wait for it) a F96T8/HO. You will probably have to go to a supply house to find those, I don't think the big box stores carry them. If you want a shorter high output lamp, you can either stick with T12 (F48T12/HO), or go to T5 with F54T5/HO fixtures. How high are you ceilings? BTW, ditch the Philips Alto lamps. They are known to kill ballasts. Sylvania and GE make good quality lamps.

 

[BatteryCharger]

BTW, ditch the Philips Alto lamps. They are known to kill ballasts. Sylvania and GE make good quality lamps.

Hmmm...that sucks, since I have like 18 of them...but I'm not too fond of the ballasts anyway. Is 8800 lumens the most I can get from the 8' T12 HO fixtures? (110w?)

Also, would I be correct in thinking that if the tubes don't have ANY blackening around the ends, (any kind of tubes) they're probably relatively new?

 

[mousehunter]

I read that originally t-8 were designed as 40 watt tubes. Then someone noted that the smaller tube was more efficient at getting light to the workspace. That would cause retro fit installations to be brighter than the t12's they replaced. The simple fix was to cut the output from the electonic ballists.

That said, there are ballasts that push the t8 hotter than others. Then there is odno. Seems that the t-8's can actually take a little bit more than 40 watts. Certain e-ballast can be tricked by bridging channels (the feature is in them so they can drive other tubes than t-8) to push out a bit less than 50 watts. ODNO (overdriven normal output) are some bright t-8's. They are often used by the aquarium hobbies that need a lot of light, but have limited space to mount them (of course t-5's are a better choice, but the bulbs cost a lot more).

My aquarium originally had metal halide lights (very bright point source), but I got tired of burning out $80 bulbs. To keep light on while bulbs were on order, I built an odno - it was great, but now run a pair of 96 watt cf's in the same place (the odno is a task light in my shop now).