Burnout of 6300 Lumen Light Bulb: Why?

[CookieSalesman]

So I purchsaed this 6300 lumen light bulb, clear white glass, with a tugsten fillament.

I have this small desk lamp that used to have some 30 or 60 watt light bulb installed. I replaced that with the more powerful one, but... why did the more powerful one burn out? One day, it just burned out. And I only had it for a few hours. Is it normal for a bulb to be... really really hot? I felt like you could heat a small room with the bulb alone.

Is there something with the voltages or current?

I mean it's a normal 120 volts, directly into the wall socket.I don't get this. SHouldn't any bulb work? No matter the lumens? (I know luminosity isn't the proper measurement, but there's basically a correlation. Right?

 

[PietKuip]

Lamps usually have a sticker saying the maximum allowed wattage. If you use bulbs with more power, you risk fire etc.

I guess that you used a halogen light bulb. Those need to be handled with care, the glass surface must not have fingerprints.

 

[CWatters]

How well ventilated is the light fitting? A more powerful bulb may run hotter.

 

[CookieSalesman]

How well ventilated is the light fitting? A more powerful bulb may run hotter.

It's about as well ventilated as possible, it's completely open except for an open cyllindrical lampshade around it.

What do you mean by allowed wattage in lamps?

 

[Jimmy]

What do you mean by allowed wattage in lamps?

This:
https://spkiehmphysics.files.wordpress.com/2013/02/photo1.jpg

Usually 40 or 60 is the maximum recommended. Your bulb probably got too hot in its enclosed space.

 

[Drakkith]

What do you mean by allowed wattage in lamps?

Lamps can only handle so much power running through them. If you put in a bulb that exceeds the allowed wattage you risk burning out the lamp's wiring, starting a fire, etc.

 

[CookieSalesman]

Wait... so how do bulbs more than 60 watts ever plug in anywhere? I've never seen anything like a 100w socket or whatever.

 

[Jimmy]

Wait... so how do bulbs more than 60 watts ever plug in anywhere? I've never seen anything like a 100w socket or whatever.

For small desk lamps—which is what you mentioned in your original post—60 W is a typical maximum rating. The table lamp I have in my living room is rated at 150 W. It just depends on the lamp.

 

[DaveC426913]

Sure, most desk lamps are rated at less than other receptacles, but that's to protect the lamp from melting not to protect the bulb from burning out.

Any reason not to assume the OP just got a bad bulb? Or is it possible that a higher wattage bulb gets more brittle?

 

[davenn]

I guess that you used a halogen light bulb. Those need to be handled with care, the glass surface must not have fingerprints.

This is the most appropriate and most likely reasonDave

 

[Jimmy]

Sure, most desk lamps are rated at less than other receptacles, but that's to protect the lamp from melting not to protect the bulb from burning out.

True but over-heating is a common cause for short bulb life.

 

[DaveC426913]

I guess that you used a halogen light bulb. Those need to be handled with care, the glass surface must not have fingerprints.

This is the most appropriate and most likely reason

The OP said 6300 tungsten bulb. Halogen bulbs are often not compatible with different wattages of other halogen bulbs, let alone with tungstens.

 

[davenn]

The OP said 6300 tungsten bulb. Halogen bulbs are often not compatible with different wattages of other halogen bulbs, let alone with tungstens.

Any of the high wattage bulbs are susceptible to fingerprints on the glass envelope
still a very valid answer

 

[DaveC426913]

True but over-heating is a common cause for short bulb life.

Yeah but that still doesn't make sense. Why would a bulb in an open lamp (as the OP points out, as open as it can get) overheat more than the bulb stuck in some enclosed lamp supporting a higher wattage?

 

[DaveC426913]

Any of the high wattage bulbs are susceptible to fingerprints on the glass envelope
still a very valid answer

I know halogens are. I am highly dubious that tungsten bulbs are. I don;t think the OP is talking about anything more powerful that a 100 or 150 watt bulb.

Well, OK. Here's a 300W 6300 lumen tungsten:
https://www.fastenal.com/products/details/0710993

Though I'm not sure these giant mostly-vacuum bulbs are susceptible to fingerprints like tiny halogen.

 

[davenn]

I know halogens are. I am highly dubious that tungsten bulbs are.

I have seen more than a few tungsten floodlight lamps die for that reason ... hell probably killed a couple myself before anyone told me DONT TOUCH the glass ... hahaha
It's the fingerprints that cause hotspots on the high temp glassdon't forget they are all tungstens ... halogen is just the gas filling

 

[DaveC426913]

OK, I see your point.

Maybe we should stop guessing and ask the OP exactly what bulb.

 

[PietKuip]

The OP said 6300 tungsten bulb. Halogen bulbs are often not compatible with different wattages of other halogen bulbs, let alone with tungstens.

Halogen bulbs have tungsten filaments.
Anyway, the OP did not provide that much information about the bulb or about the point of failure, so we are just guessing.

 

[rootone]

There isn't a direct correlation between power consumption in watts and amount of light produced measured in lumens.
However the old style incandescent bulbs are one of the most inefficient ways of doing it, halogen bulbs are only slightly better.
You could get around 3x better efficiency with flourescent and up to 6x with LED units.

Describing the heat produced by this 6300 lumen rated incandescent bulb as 'enough to heat a small room' is probably close to the truth.
A bit of googling revealed that a standard 100W incandescent bulb produces around 1600 lumens.
Your bulb which broke is equivalent to four of those, so power consumption should be in the region of 400W - which is indeed about right for a small electric bar/coil heater.
I don't know in what situation the unit was intended originally to be used, but my guess is that forced ventilation might have been necessary.

 

[CookieSalesman]

Oh no no no it was about 300 watts, (so yes close to what rootone said) standard filament, 6300 lumens. If you put paper on it, I would expect, or at least it felt like the paper would probably ignite after a while. Or at least burn up very slowly from the intense heat.

But anyways thanks everyone. I think that's about it for my questions.

 

[Drakkith]

Honestly I think you just got a bad bulb.

 

[NascentOxygen]

So I purchsaed this 6300 lumen light bulb, clear white glass, with a tugsten fillament.

I have this small desk lamp that used to have some 30 or 60 watt light bulb installed. I replaced that with the more powerful one, but... why did the more powerful one burn out? One day, it just burned out.

Had you stated the wattage of the new bulb, it would have immediately been clear why you came close to starting a fire. 60 W is about the limit for the typical desklamp fitting; exceed this and you risk damaging the hardware and wiring insulation.

It isn't conclusive that the bulb did burn out, anyway. It might be the fitting or wiring that failed. Have you tried yet another replacement? Never exceed 60W. In fact, that desklamp may not now be safe to use. It needs to be disassembled and closely examined by a qualified electrician to assess it for heat damage, and insulation may have retracted or melted to expose bare wires that could at sometime touch.

If you need more lumens, try the LED replacements---they give more light for the same wattage. A 25W LED would be about as bright as you could stand in a desklamp.

Can you see into the failed bulb's internals? You might find it isn't the filament that has melted, either. It might be the fusible link in one of the conductors between the cap and a support leg that has melted, there was so much overheating.

You should consider it fortunate that the bulb failed, this probably prevented a house fire!

 

[DaveC426913]

So... you took out a 30/60 watt bulb from a small desk lamp and tried a three hundred watt bulb?

I'd say you should thank your lucky stars you didn't set your room ablaze!

[ EDIT ] Oh. Nascent beat me to it...

 

[Vanadium 50]

Add me to the list of people whose jaws are on the floor. Three HUNDRED watts? Holy cow!

 

[rootone]

Yes, that would be in the useful range for stadium floodlights or the kind of things used for illuminating the sky in a war zone!

 

[DaveC426913]

A picture of CookieSalesman's hometown.

 

[rootone]

All said and done though, why have LEDS remained high priced despite the technology being by now quite old?
It made sense to me to start replacing worn out incandescent and fluorescent bulbs about ten years ago, but LEDs remain the same expensive unit price.
I might just go back to bargain basement CFLs for a while, since they do live up to expectations, LEDs maybe not so much.

 

[CWatters]

It still needs a semiconductor fab line where as an incandescent bulb is lower tech. I believe the answer is also partly down to the warranty. It's possible to buy cheap LEDs bulbs from china but don't expect a great warranty. It's still hard to make an led bulb survive even the lower heat it generates.

 

[CWatters]

I won't go back to cfl bulbs ever again. LEDs are better. I use a lot of 230V GU10 LED bulbs rated at around 400 to 450 Lumens. Some are a few years old now.

 

[sophiecentaur]

It could be to do with a high resistance contact (dirt / weak spring). That could be making the base hot and compromising the seal where the wires enter the envelope. I seem to remember that bulbs 'hanging down', rather than standing up were said to have shorter lives because of the base and receptacle temperature was higher.

 

[NascentOxygen]

I purchased a few samples of cheap LED bulbs direct from China (free postage). Their life seems okay, but besides some exhibiting an uneven spectrum (too blue), they nearly all seem characterised by bad RFI and cause horrible sizzling noise on an AM radio in the next room.

 

[Nugatory]

Yes, that would be in the useful range for stadium floodlights or the kind of things used for illuminating the sky in a war zone!

I use a pair of 500-watt halogens (in lampholders designed for this purpose, of course and an electric circuit rated for the load) for winter-time project lighting in my shop space. The ceiling is white and maybe four meters high... Point the lampholders straight up and the ceiling diffuses the 15,000+ lumens into a nice bright shadow-free pool of light about five meters across.

This is not exactly ordinary everyday lighting

 

[DaveC426913]

I use a pair of 500-watt halogens (in lampholders designed for this purpose, of course and an electric circuit rated for the load) for winter-time project lighting in my shop space.

and heating!

 

[CookieSalesman]

Lol thank you everyone for the answers and explanations.
But the bulb actually worked for a number of hours, and was quite satisfactory, until it simply stopped.

Then my roomate and I, both by chance, physics majors broke the lightbulb open, re-hinged the tungsten on the legs and turned it on, exposing it to air. It burned a nice red, before melting down.

 

[Drakkith]

Well stop slamming that filament and it might stay on its hinges! Were you raised in a barn? A barn where they had filaments you could slam all day to your heart's content?!

 

[Tom Rauji]

Many of the answers here are completely unrelated to one-day filament life, especially wattage and finger prints. A filament is designed for a certain voltage. When normal voltage is applied, the filament (from current flow through the cold resistance) rapidly heats to a certain temperature. That temperature, along with filament design, sets the hot running wattage and current. The short term life is related only to mechanical considerations like shock or vibration, build quality, and running voltage. If it is a 120V lamp on 120 nominal voltages, it will have the same short term life virtually independent of fixture dissipation rating. This is because there is immeasurable difference in filament temperature based on envelope temperature.

The main deterioration from finger prints or ventilation (dissipation) is long term envelope damage. It takes a pretty messy fingerprint to hurt an envelope by making a hot spot. Most damage worries from excessive wattage are long term gradual thermal damage to the socket area from heat.

If his lamp voltage was correct, for one day life he almost certainly either received a bad bulb or the bulb had mechanical shock or vibration damage. Higher light emission bulbs have shorter life for a given style of construction because the filament runs hotter, but he had an extreme. It is 100% certain if he had the correct voltage, a one day life could only be from a damaged or defective lamp.

 

[DaveC426913]

Are you saying that fingerprints on a halogen bulb is essentially a myth?

 

[Tom Rauji]

Are you saying that fingerprints on a halogen bulb is essentially a myth?

Not as much a myth as over-blamed. The failure mechanism from oil or other contaminants is localized hot-spotting of the envelope. It can cause envelope failure in the contaminated spot by localized heating, which if significant might cause the quartz envelope to crack or melt. It does not cause shorter filament life, unless the envelope heats so much it fractures or melts in that spot and "leaks air". That would generally discolor the glass with a milky color. I would certainly avoid doing anything that might hot-spot the envelope, but unless the envelope actually fails at the contamination site the contamination would have no impact on life. In this case in particular, it is not a one day event unless the contamination was something pretty severe and it melted a hole through the envelope

 

[DaveC426913]

Not as much a myth as over-blamed. The failure mechanism from oil or other contaminants is localized hot-spotting of the envelope. It can cause envelope failure in the contaminated spot by localized heating, which if significant might cause the quartz envelope to crack or melt. It does not cause shorter filament life, unless the envelope heats so much it fractures or melts in that spot and leaks air. I would certainly avoid doing anything that might hot-spot the envelope, but unless the envelope actually fails at the contamination the contamination would have no impact on life. In this case in particular, it is not a one day event unless the contamination was something pretty severe and it melted a hole through the envelope

Huh. Thanks I always wondered about the logic of that.

I also always wondered whether it was better to cool a bulb with the fan after shutting down, or just let it dissipate the heat on its own.

 

[Tom Rauji]

Huh. Thanks I always wondered about the logic of that.

I also always wondered whether it was better to cool a bulb with the fan after shutting down, or just let it dissipate the heat on its own.

Cooling really depends on what is failing and why it is failing. I've never measured small lamps, but I have measured vacuum tubes that primarily cool through IR. In high vacuums with glass envelopes, most of the dissipation is via IR. Some is by thermal conductivity of pins and pin leads. In high power vacuum tubes, problems center around socket deterioration or bonding failures in metal/glass seals. There is no reason to think lamps would behave differently. There can be some overshoot in seal temperatures with a hard shutdown. The question would always be if seal failure is a life issue. It is probably safer to leave air on as long as the air cools the seals and socket pins.

 

[sophiecentaur]

Huh. Thanks I always wondered about the logic of that.

I also always wondered whether it was better to cool a bulb with the fan after shutting down, or just let it dissipate the heat on its own.

I always understood that it is best to use a dimmer to turn off a high power lamp. Theatre lights (hundreds of Watts) take a lot of on/off stick and i think they survive because dimmer controllers are more gentle with them in that way for the same reason.
High power thermionic tubes are usually protected from hard shutdown.

 

[SongDog]

Sounds like a bog-standard grossly inefficient "warm white" 2700K 300W at 120V incandescent like Philips 38941-1 listed on page 138 of https://www.platt.com/CutSheets/Philips%20Lighting/Philips-IncandescentLamps-CatalogPage-2011.pdf It appears the "300W" is closer to 282W (perhaps misrepresentation as marketing?)

Of course it runs hot: about 90% of that wattage is heat. There's really no excuse for continued use of these antiques: they are wasteful, expensive, and occasionally even dangerous. Use LEDs if you can, CFs if you can't.

 

[CookieSalesman]

That's a new development...

So now what should I do...?

Suppose I want some bright lighting; I actually did not know about the whole fingerprint thing, the bulb was probably covered in my fingerprints. Does this mean I can purchase a new 300W bulb, not touch it, and i'll be fine for at least... a long time?

 

[DaveC426913]

Does this mean I can purchase a new 300W bulb, not touch it, and i'll be fine

Have you not been paying attention?

 

[CookieSalesman]

I have...

It seems at the end of page 2, someone suggests that it must be a defect, for only lasting one day.

 

[DaveC426913]

"... you came close to starting a fire ..."
"... you should thank your lucky stars you didn't set your room ablaze ..."
"... Add me to the list of people whose jaws are on the floor. Three HUNDRED watts? Holy cow! ..."

The danger exists because of your use of the bulb, not because the bulb failed.

 

[Drakkith]

I have...

It seems at the end of page 2, someone suggests that it must be a defect, for only lasting one day.

If the bulb didn't crack, I would guess that you had a defective bulb. However, if you're going to get a replacement bulb, do NOT use it in your lamp. If you want a bright light for that lamp, use an LED or CFL instead.

 

[CookieSalesman]

Alright thanks everyone.

 

[Tom Rauji]

Too many wives tales about filaments. Shut down speed or ramp-down of the filament is meaningless. It is the ramp up that sometimes, in rare cases, will reduce life. This is because cold resistance of the filament is many times less than hot resistance, so the filament dissipates a great deal of energy during startup. This can lead to "hot areas" in the filament, generally at the weakest thinnest areas, causing thermal stresses. This effect is called "inrush" or "inrush current". It lasts many cycles of a 60Hz power mains, so zero crossing turn on is pretty much meaningless. It is the surge current over many dozens or hundreds of cycles that causes the issue, and only when powering on from a cold start.

The importance of minimizing inrush varies greatly with the filament type. In many cases inrush is meaningless, in some cases it affects filament life a great deal. One of the parameters that determines importance of inrush would be the total running hours compared to the number of cold starts. Obviously a short run time with many starts is a much worse situation than a long run time with infrequent cold to hot start cycles.

 

[interestedcrl]

InterestedCRL -- I think incandescent filament bulbs have greatly lost their lasting quality since Congress passed laws allegedly to 'save enengy', which affected that type of bulb quality. But I think more unnecessary burnouts and more sales were the real motivation of the law, and not consumer health, safety, nor 'pro-environment'.