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General => Lounge => Topic started by: jcassity on August 03, 2008, 03:31:43 PM

Title: flourecent bulbs
Post by: jcassity on August 03, 2008, 03:31:43 PM
something does not add up...........
13w
120v
175mA


humm........  look closer next time you buy i guess.  I think they are allowed to derate by 60% iirc but still., average power or not, its still misleading.

This one was still cooking and we smelled it but could not figure out where it was coming from.  I told the wife it smelled like electrical and so i shot outside to see if someone from far away was burning stuff.  outside smelled good, inside smelled bad.  I go under the house and check for smoke in the crawl space and no smoke. 
I was about ready to kill the main breaker cause it was so bad.

Chance hollers at us saying he has a bulb that went out just now.  The pic is what we find,, the little transformer in there is still drawing current but no light.  The housing along the containment area is plastic and was hot to the touch.

What a scam on rating wattage though.
Title: flourecent bulbs
Post by: TurboCoupe50 on August 03, 2008, 03:46:40 PM
I've heard if them overheating, but the ones I had just died...

175ma translates to 21w at 120v...

http://ourworld.compuserve.com/homepages/Bill_Bowden/ohmslaw.htm

I just dragged a package out of the closet and these GEs are rated 13W @ 200ma...
Title: flourecent bulbs
Post by: jcassity on August 03, 2008, 03:54:00 PM
:rollin:

humm,, maybe all of them do it.  Im gonna bust open the container here in a min and find out whats in there for sure.  I thought most of them had a fuse,,,, along with the mercury.
Title: flourecent bulbs
Post by: jcassity on August 03, 2008, 04:00:22 PM
heck,, that might be the secondary rating,, i suppose that makes sense then. 

that means them there bulbs of yours are secondary 65v.

Still though,, thats the wrong side of the fence for the consumer i think.  the utility draw is on the primary,,,

They are selling by the secondary wattage.
Title: flourecent bulbs
Post by: Ifixyawata on August 03, 2008, 07:48:35 PM
You electrical nerds and your gigawatts and megavolts...
Title: flourecent bulbs
Post by: jcassity on August 03, 2008, 11:32:27 PM
me and  my pocket protector:rollin:
Title: flourecent bulbs
Post by: daminc on August 04, 2008, 12:01:42 AM
I have found, that the cheap ones cook like that when they are used upside down. and they don't last very long.
What brand was that bulb?
the cheap bulbs from SAMs club cook also.
Haven't had any problems with GE lately.
Title: flourecent bulbs
Post by: EricCoolCats on August 04, 2008, 10:07:48 AM
I'm all for saving energy and being more energy efficient...but I will NEVER use a bulb that looks like it was unscrewed from someone's balloon knot. Y'all can keep 'em...
Title: flourecent bulbs
Post by: Thunder Chicken on August 04, 2008, 11:19:36 AM
:rollin::rollin::rollin::rollin::rollin:

Every bulb in my house is a CFL, except the three in my living room ceiling fan, and that's because they are exposed and I don't want people looking at "balloon-knot bulbs" in my house. All of the other bulbs are hidden behind shades, so their looks aren't particularly important. I've only had two fail since I bout the house two and a half years ago. One was the outside light (so I can blame that on temperature extremes and moisture) and one was a basp00get light that I hit with my head one time (it still worked but was loose in the base, and burned out a few weeks later).

As for their energy consumption, I would hazard a guess (and this is strictly a guess) that the higher amperage rating is to allow for start-up. Flourescent bulbs, like electric motors, require more energy when they're first energized. Most actually have a small metal element just like a normal light bulb that has to heat up before there's light.

I would imagine they have to post the maximum current draw so that a circuit could be sized accordingly. It would make little difference in a typical house, but in, say, a restaurant, where there may be dozens on a single switch, it would all add up. Most 120v circuits are rated at 15 amps, so you'd be limited by how many bulbs can be installed on that circuit based on their current draw. If you installed a bunch of bulbs based on their wattage (which works out to a lower current draw than the mA printed on the bulb) you might, in theory, blow a fuse or breaker the moment you flick the switch because the startup current of all of those bulbs would be too high.

For the record, I'm holding a 10-watt bulb from my bedroom table lamp that has a 140mA rating. That 140mA would work out to 16.8 watts at 120 volts.
Title: flourecent bulbs
Post by: TurboCoupe50 on August 04, 2008, 02:51:27 PM
Quote from: Thunder Chicken;230517

As for their energy consumption, I would hazard a guess (and this is strictly a guess) that the higher amperage rating is to allow for start-up.


Here's the real reason for the higher current rating... This is lifted from another forum where I post regularly...

Quote from: "doug houston"
Ohm's law applies to AC, only if voltage and current are in phase. This is spoken of as 100% power factor, or unity power factor. Power law for AC would be: Volts X Amps X power Factor in percent.

In DC circuits, Current and voltage always flow together, but in AC circuits, inductive reactance and capacitive reactance cause voltage and current to flow through a circuit, time (phase)-spaced from each other. This is said that current either leads voltage (capacitive circuit), or lags voltage (inductive circuit). You get into trigonometric calculations, that are not easy to describe here.

As an AC cycle progresses through its 360 degrees, say, that current lags voltage by some number of  those degrees. The cosine of that angle will be the power factor for that circuit, expressd as a percentage. This is graphically displayed by a right triangle, where the X axis is  real power (which does work. The opposite side (y-axis), is reactive power, which does no work, and the hypotenuse is the power that the power company supplies. The cosine of the angle between voltage and current is the power factor.

 Thus, the power company will make a big user pay extra for low power factor power use, because the power waste in reactive power must be borne by the user, who has machinery, or whatever, that wastes power .  Purely resistive loads, like heaters or incandescent lights, will show unity (100%) power factor.

Returning to the original question, that Curt has already addressed, This little fluorescent light has an inductive device to fire the gas in it, and cause the phosphor in the glass to glow. Since it is inductive, the thing will have a lagging power factor, which accounts for the lower wattage rating than Ohm's law will tell. Fluorescent lights, as we know them, cannot have a unity power factor. He also pointed out that the rating of the thing should have shown it in volt-amperes. Nobody wants to admit to a low power factor!

As  you can see from the above quagmire, AC circuits are far more complicated that DC, and involve some pretty hairy mathematics. It's been 56 years since I had a slide rule smoking,  while cranking out answers to those problems.
Title: flourecent bulbs
Post by: daminc on August 04, 2008, 07:03:50 PM
Quote from: EricCoolCats;230508
I'm all for saving energy and being more energy efficient...but I will NEVER use a bulb that looks like it was unscrewed from someone's balloon knot. Y'all can keep 'em...


LOL, they now have them looking like regular bulbs.
Come on, you know you want them.
Title: flourecent bulbs
Post by: EricCoolCats on August 04, 2008, 11:25:50 PM
Quote
Come on, you know you want them.

I just don't see CFL's as the solution right now. I appreciate the idea behind them but the technology just isn't perfected yet, especially with the generous use of dangerous mercury.

I'm using LED bulbs. Already converted most of my kitchen to LED, just need a few other odds-and-ends bulbs in LED and I'll be done with the house. Outdoor lighting is all LED now. Garage is all standard flourescent, basp00get soon will be also. LED's are still the standard (lowest power consumption, relatively no heat, 20+ year life). My outdoor LED spotlights, running on an average of 12 hours a night every night, add a whopping $5 a YEAR to my electric bill.

So again, y'all can keep the squiggly bulbs, I don't need 'em. :flip:
Title: flourecent bulbs
Post by: ZondaC12 on August 04, 2008, 11:34:35 PM
How's the tone??? My mom has some encased bulb-like CFL's in our house and it looks just like an incandescent bulb's light. Are they doin that with the LED ones too? I have a 6-LED flashlight and that thing is nuts especially for its small size. Theyre definitely the ticket.
 
Though I will say....Im old school I guess.....I dont like car turn signals/brake lights going on/off INSTANTLY as I see on some new models using LEDs...something about the slower dimming and brightening just sits a lot better with me. :D :rolleyes:  Im weird like that.
Title: flourecent bulbs
Post by: softtouch on August 09, 2008, 05:34:33 PM
Quote from: TurboCoupe50;230547
Here's the real reason for the higher current rating... This is lifted from another forum where I post regularly...

That is a good write up.