if my fluorescent light works intermittently, does that mean the bulb is about to go?

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zinfamous

No Lifer
Jul 12, 2006
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Originally posted by: Jeff7
Originally posted by: SparkyJJO
Originally posted by: Jeff7
(And as for the mercury thing, burning coal releases mercury into the air. More power for incandescent = more coal burned = more mercury in the air.)

My brother works at a coal plant. They go through great lengths to be sure that stuff does not go into the air. Very strict regulations on that kind of thing. Very little actually ends up in the atmosphere.
Ah, cool. Did not know that.

Google-found link.
The Clean Air Mercury Rule was built on EPA?s Clean Air Interstate Rule (CAIR) to significantly reduce emissions from coal-fired power plants -- the largest remaining sources of mercury emissions in the country. The goal of these rules regarding mercury was to reduce utility emissions of mercury from 48 tons a year to 15 tons, a reduction of nearly 70 percent.
Some does still seem to get out, but a reduction is definitely good.

It is indeed much better, I suppose...but "clean coal" is an insane misnomer.
 

zinfamous

No Lifer
Jul 12, 2006
111,555
30,775
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Originally posted by: FelixDeKat
Originally posted by: Jeff7
Originally posted by: Rubycon
How old is it? If it has a class P electromagnetic ballast and it's getting too warm the thermal protector will engage and extinguish the lamp. However you should NOT see the ends glowing slightly although with 277 volt systems it can happen if you have flying neutrals with potential on them.

Preheat systems will do this if the bulb contacts are corroded or the bulb is just getting weak.

There is nothing wrong with fluorescent lighting particularly where color rendering is of secondary concern. Their lumen maintenance is good compared to other forms of lighting. You can get high CRI if sacrifice of efficacy is acceptable.
Uh oh, dis shit just got real.



:D

If I found out she holds a degree in everything it wouldnt suprise me one bit.

Sometimes, I think people just post threads in OT only to see how Rubycon will respond
:)
 

dawp

Lifer
Jul 2, 2005
11,347
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just might be corosion in some of the contacts too. had that problem with a saltwater aquarium i have.


as far as the brightness of CFLs, i got some nice yellowish shaded ones that look almost the same as incadecent bulbs. you just have to try different kinds to find what you like.
 

Rubycon

Madame President
Aug 10, 2005
17,768
485
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Originally posted by: BigJ
Define that. Do you have T12 or T8 bulbs? Or even T5 bulbs? Are these old bulbs, or are they brand new?

As far as other inquiries, florescents vary greatly. Color temperature (the XXXXXk value on the bulb) will determine what kind of light you get out of the bulb. The closer it is to zero, the yellower they will be. The higher they are, the bluer they will be. Generally, I like 5000k bulbs for general lighting, with 4100K (Cool White generally) for reading and tasks.

The ballast is definitely not part of the bulb in typical tube fluorescents. The bulbs will typically be independent of the ballast. In most common CFLs, the bulb will have the ballast built into it.

As far as Rubycon is concerned, I don't know of any residential lighting that has 277v going to it. CRI is an issue with cheaper fluorescent tubes, but not if you spend the money, and they are just as efficient as normal fluorescent tubes.. The more expensive fluorescents will have a 90 CRI or better, which most people will never be able to distinguish from incandescents and halogens. That said, in most environments where homeowners are concerned (such as basements or shops) CRI is of no importance. In residential lighting, I have never heard of thermal-protection kicking in.

CRI is independent of color temperature. You can have a 5000K lamp with a CRI of 50 and another could have a CRI of 96. Those are quite extreme though.

You've never seen a class P on 120V overheat and open the bimetal protector? 277 and 480 ballasts are going to have faster insulation breakdown for sure but I'm sure there are ancient (tar) ballasts still out there that are snapping on and off. ;)

p.s. the typical 4100K CW bulb with a CRI of 69 is quite gloomy looking. They've been lighting factories and offices for years before the recent upgrades to better quality lighting in the 90's, namely T8 electronically ballasted fixtures.
 

Gothgar

Lifer
Sep 1, 2004
13,429
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Originally posted by: Colt45
Originally posted by: Jeff7

The Clean Air Mercury Rule was built on EPA?s Clean Air Interstate Rule (CAIR) to significantly reduce emissions from coal-fired power plants -- the largest remaining sources of mercury emissions in the country. The goal of these rules regarding mercury was to reduce utility emissions of mercury from 48 tons a year to 15 tons, a reduction of nearly 70 percent.
Some does still seem to get out, but a reduction is definitely good.

15 tons >>>>>>>>>>>>>>>>>> ~25mg in a 4' tube




Hmm.. Just googled a bit, apparently 12mg is the norm for a four footer now.
So that 15 tons is good for 1.2 BILLION four foot tubes.

I guess if every man, woman, and child in the US breaks four 4' tubes a year, it would be the same.

is that per plant though?
 

Rubycon

Madame President
Aug 10, 2005
17,768
485
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Originally posted by: MotF Bane
Is there any question Rubycon can't answer?

Oh believe me there is plenty. If I knew everything I'd have a field day in P & N. ;)
 

BoomerD

No Lifer
Feb 26, 2006
65,602
13,980
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Originally posted by: Rubycon
Originally posted by: MotF Bane
Is there any question Rubycon can't answer?

Oh believe me there is plenty. If I knew everything I'd have a field day in P & N. ;)

I think I'd buy tickets to see that...:D
 

Jeff7

Lifer
Jan 4, 2001
41,596
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It looks like that "15 tons" figure is the goal for the entire country's coal-fired power plants.
Going from 48 to 15 is a reduction of 68.75%.

Coal power = 335.8 GW in 2006.

Assuming those are English tons (2000lbs), that's 285.884lbs/GW = 129 675 008 milligrams/GW = 0.129675008 milligrams per watt.
So for a 100W incandescent, that'd be 12.9675008 mg/hour.
Vs a Neolite 23W CFL: 2.982525184 mg/hr + (1mg @ start of life)

Under the new 15 tons rule:
100W incandescent: 4.052344 mg/hour
23W Neolite CFL: 0.93203912 mg/hr + (1mg @ start of life)

Looks like fluorescent wins.


For tubes, I don't have time to run the calculations, but here are some numbers:
100W incandescent = 1710 lumens
32W T8 fluorescent = 2950 lumens
1.7mg of mercury per tube (Philips Alto II).

32W of tube = 172.51W of incandescent

 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,601
167
111
www.slatebrookfarm.com
Originally posted by: Colt45
Originally posted by: Jeff7

The Clean Air Mercury Rule was built on EPA?s Clean Air Interstate Rule (CAIR) to significantly reduce emissions from coal-fired power plants -- the largest remaining sources of mercury emissions in the country. The goal of these rules regarding mercury was to reduce utility emissions of mercury from 48 tons a year to 15 tons, a reduction of nearly 70 percent.
Some does still seem to get out, but a reduction is definitely good.

15 tons >>>>>>>>>>>>>>>>>> ~25mg in a 4' tube




Hmm.. Just googled a bit, apparently 12mg is the norm for a four footer now.
So that 15 tons is good for 1.2 BILLION four foot tubes.

I guess if every man, woman, and child in the US breaks four 4' tubes a year, it would be the same.

Not quite sure what your point is. Are you implying that the electricity production is far worse for releasing mercury than broken florescent bulbs? If that's the case, then, yes, we already knew that. However, your statistic is meaningless, because not all 15 tons of mercury come from production of electricity exclusively for lighting.
 

Paperdoc

Platinum Member
Aug 17, 2006
2,435
344
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I get the impression (because OP is concerned about replacing the ballast) that the question is about classic fluorescent tubes in fixtures with permanent ballasts, not about the Compact Fluorescent Bulbs that screw into regular incandescent fixtures.

OP, any fluorescent tube will develop discoloration in bands around each end. This is the result of sputtering of the metal contacts at each end over time. Typically when the bands get real dark is when the bulbs get weak and quit working. And yes, intermittent operation with dark ends usually means the bulb is about to fail.

By far the most common mode of failure in fluorescent fixtures is the bulb fails. Ballasts last MUCH longer. So since the bulb is so cheap (compared to ballasts) I usually replace the bulb first. If that does not work, only then do I suspect ballast failure.

In 2-tube fixtures, many people will replace both tubes in the pair rather than just the dark one, on the hypothesis that the second one, being of the same age, is going to fail anyway sometime soon. Others replace only the failed one, and do the other only after it fails, too. Your choice. The replace-in-pairs way tends to happen more when the fixture is really hard to get up to (twice), of in industrial settings where you are paying big bucks to some worker to do two replacements instead of one.
 
Jul 10, 2007
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Originally posted by: Paperdoc
I get the impression (because OP is concerned about replacing the ballast) that the question is about classic fluorescent tubes in fixtures with permanent ballasts, not about the Compact Fluorescent Bulbs that screw into regular incandescent fixtures.

OP, any fluorescent tube will develop discoloration in bands around each end. This is the result of sputtering of the metal contacts at each end over time. Typically when the bands get real dark is when the bulbs get weak and quit working. And yes, intermittent operation with dark ends usually means the bulb is about to fail.

By far the most common mode of failure in fluorescent fixtures is the bulb fails. Ballasts last MUCH longer. So since the bulb is so cheap (compared to ballasts) I usually replace the bulb first. If that does not work, only then do I suspect ballast failure.

In 2-tube fixtures, many people will replace both tubes in the pair rather than just the dark one, on the hypothesis that the second one, being of the same age, is going to fail anyway sometime soon. Others replace only the failed one, and do the other only after it fails, too. Your choice. The replace-in-pairs way tends to happen more when the fixture is really hard to get up to (twice), of in industrial settings where you are paying big bucks to some worker to do two replacements instead of one.

awesome thx.