Reduced output fluorescent?

[titan1021]

I'm bidding a remodel/addition and the architect has spec'd out reduced output electronic T8 fixtures (troffers). An actual fixture has not be spec'd.

I can't seem to find any fixtures or information regarding reduced output fluorescent fixtures. I've been all over Lithonia's website and couldn't find anything.

Any input or direction would be greatly appreciated.

Thank you.

 

[jeremysterling]

Maybe he means F28T8 instead of F32. They use the same ballast, though.

 

[titan1021]

That makes sense, I was just trying to figure out if its the lamp or a specialized ballast that makes the fixture a reduced output fixture.

 

[jeremysterling]

Some of our customers remove a lamp or two. That reduces the output, ha ha!

 

[TNBaer]

What he's probably asking for is .77 ballast factor and 28 watt lamps. This seems to be the system that is becoming more and more of standard.

I do not recommend Lithonia or Cooper, asking for specialized ballasts in either of those brands will take upwards or two months.

You can go to a specialized source, like Optimum or US Energy Sciences (three week delivery, typically, and very nice product). Hubbell's brand "Columbia" offers this in a ten day quick ship as well, so material can be gotten painlessly.

http://www.columbialighting.com/products/4ps/

 

[Electric-Light]

That makes sense, I was just trying to figure out if its the lamp or a specialized ballast that makes the fixture a reduced output fixture.

It's either or.
There are four or five different ballast ratings.
The lamp's lumen rating is based on reference ballast rated at 1.00, but they're rare.
There are:
<0.7
0.77 L
0.88 "standard"
1.00 N+ (I think only GE offers this)
1.15 to 1.20 H (used for high bays and such)
Ballast changes output by having different drive current.

48" T8 lamps are available in 32W(standard), 30W, 28W and 25W.
Lamps change output by changing operating voltage when operated on a current source. They do this by using different gas blends (ratios of Argon to Krypton. 32W is 100% argon, 25W is almost 100% Krypton)


It is noted somewhere in a Philips literature. 25W lamps are unreliable below 50F, but they're more "fade" resistant at higher temperature meaning that optimum efficacy is reached at higher temperature than 32W and loss of efficacy at elevator temperature in semi/fully enclosed luminaires is lesser.

 

[TNBaer]

It's either or.
There are four or five different ballast ratings.
The lamp's lumen rating is based on reference ballast rated at 1.00, but they're rare.
There are:
<0.7
0.77 L
0.88 "standard"
1.00 N+ (I think only GE offers this)
1.15 to 1.20 H (used for high bays and such)
Ballast changes output by having different drive current.

48" T8 lamps are available in 32W(standard), 30W, 28W and 25W.
Lamps change output by changing operating voltage when operated on a current source. They do this by using different gas blends (ratios of Argon to Krypton. 32W is 100% argon, 25W is almost 100% Krypton)


It is noted somewhere in a Philips literature. 25W lamps are unreliable below 50F, but they're more "fade" resistant at higher temperature meaning that optimum efficacy is reached at higher temperature than 32W and loss of efficacy at elevator temperature in semi/fully enclosed luminaires is lesser.

You know anyone using those 30 watters? I never see them anywhere. The 28 watters are preferred by most ESCOs though I know guys using the 25s.

 

[BullsnPyrs]

30 watt lamps

30 watt lamps

It seemed to me that the industry dveloped the 28 watt lamps at almost the same time. Installations seemed to skip from 32 watt to 28 watt. The only use i can see for them is for relamp on older ballasts that do not perform well with 28 or 25 watt lamps.

 

[spark master]

Do the 28 watter run off the same ballast as the 32watters ?
I never tried the 28's, because the 32's loose light with age, so I can't imagine how the 28's are when they age out.

 

[Electric-Light]

You know anyone using those 30 watters? I never see them anywhere. The 28 watters are preferred by most ESCOs though I know guys using the 25s.

Not really. I've seen them in catalogs, but I see its not offered by Philips. Must have been the trend in early 00's.

It seemed to me that the industry dveloped the 28 watt lamps at almost the same time. Installations seemed to skip from 32 watt to 28 watt. The only use i can see for them is for relamp on older ballasts that do not perform well with 28 or 25 watt lamps.

Do the 28 watter run off the same ballast as the 32watters ?
I never tried the 28's, because the 32's loose light with age, so I can't imagine how the 28's are when they age out.

I'm not sure what you're talking about. 32W linear fluorescent is still one of the most stable light source we have with decay of only about 5% over the useful life. This is better than just about all LEDs and all discharge lamps, except maybe low-pressure sodium.

25/28/30 48" T8s are meant to be used with ballasts meant for F32T8. They may have trouble with older rapid start type (especially Motorola) because the starting voltage on them are low and these lamps need high OCV for reliable starting. Definitely should NOT be used with magnetic rapid start T8 (rare, but exists).

Once started, the 25W lamp presents it self to the ballast pretty much like a F25T8(36") lamp.

The 25W lamp has a sweet spot that's about 10F higher than F32T8, just like T5s due to the fact it has a different fill gas blend.

28W lamps, I'm not totally sure about. They use the same phosphor as 3100 lumen lamps, which is the premium RE80. The mean(in lighting industry, this means after 40% of lamp life is spent) lumen performance is almost the same as the RE70s that were outlawed for production in July (SP, 7xx, etc)