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Posted By: schenimann exploding bulbs - 07/09/13 01:18 AM
I've got a customer that I installed 60-70 4" rework cans for. Some of these are eyeballs. They have had a few bulbs "blow up". They have put in a few of the 60watt par 16 bulbs. I think that these are the ones that have been a problem. They are the only bulbs that fit in the Juno eyeballs. I think they exceed the rating of the can and trim. Would this extra heat cause this to happen to the bulbs?

They are trying to maximize the light output for the cans. Any suggestions?
Posted By: Lostazhell Re: exploding bulbs - 07/09/13 05:01 AM
I've heard of lamps burning out prematurely, but exploding?? confused Huh.... Are there momentary voltage spikes or moments when other loads are off where the voltage could be going high?

Have you tried 130V. lamps? or CFL style par 16's?
Posted By: BigB Re: exploding bulbs - 07/09/13 06:16 AM
Originally Posted by schenimann

They are trying to maximize the light output for the cans. Any suggestions?


Yes, LEDs.

I have seen lamps explode when there was a loose/flakey neutral condition. Once is was a 60 watt A-19 in a pendant, the other time it was a G base halogen in a wall sconce. When the halogen exploded it sounded like a gunshot and took out the protective cover as well. The wall sconce had a neutral wire literally falling out of the wirenut. This was on my own house.

Is there plenty of free air space around those 4" cans? As far as I know there is not an IC rated 4" remodel can made.
Posted By: Texas_Ranger Re: exploding bulbs - 07/09/13 01:16 PM
In Europe line voltage halogens have a reputation for blowing up in a spectacular fashion and are required to have a protective cover.

In areas with a rather low line impedance (i.e. close to a beefy transformer) incandescent bulbs also tend do die with a loud bang but usually don't explode. Sometimes the glass falls off though (probably putty failure). Apparently older high-quality bulbs used to have a fuse inside the "stem" and new ones don't, so if they fail and there's an arc flash between the ends of the broken filament there's a sustained arc at a rather high current, which usually trips the breaker.
Posted By: geoff in UK Re: exploding bulbs - 07/09/13 09:53 PM
Yes, place I work bought some cheap GLSs which had no fuse and used to fail explosively. I've also seen mains halogens which can blow out the protective glass screen, sending a near red hot disc of glass, or shards thereof, onto the lucky person below. The lesson in both cases is don't buy cheap rubbish!
Posted By: schenimann Re: exploding bulbs - 07/10/13 02:02 AM
They have put in some of the par16s with the porcelain necks. I know these are rated to high for the cans. I don't think they are having problems with the correct 45 watt bulbs. What is the heat output of a comparable "60 watt" LED bulb?
Posted By: HotLine1 Re: exploding bulbs - 07/10/13 02:31 AM
The best source of LED heat 'output' would be from the lamp mfg data sheets. A Google search of the mfg will take you there.

FWIW in my days of servicing a national chain, we had a few PAR/Halogen/HR lamps that 'blew'. IMHO, I just called it defective lamps.
Posted By: Texas_Ranger Re: exploding bulbs - 07/10/13 04:22 PM
In my experience 60W equivalent LEDs tend to be 6-9 W.
Posted By: HotLine1 Re: exploding bulbs - 07/11/13 03:48 AM
Tex:
Are you saying that the heat is only 6-9 watts??
I see a lot of LED lamps that have IMHO large heatsinks??


Posted By: Texas_Ranger Re: exploding bulbs - 07/11/13 04:04 PM
At least that's what the label says! I guess I'll have to rig a TRMS amp meter to one and check. I don't think actual power consumption is that much higher than rated power though, although of course the power supply losses likely aren't included in the label rating (same with compact fluorescents, at least so I was told).
Posted By: Alan Belson Re: exploding bulbs - 07/11/13 11:35 PM
Led ratings for lumens are about a tenth of the amperes consumed by an 'equivalent] tungsten bulb: whatever that means! Temperature is not equal to energy: the led needs a heat sink on the diode to keep it cool, [ because it is so small, it has a small radiating area], otherwise its life is shortened. The actual heat quantity emitted will be far lower than a conventional equivalent bulb, since more energy is converted to light.
Posted By: HotLine1 Re: exploding bulbs - 07/12/13 04:00 AM
Alan:
Thanks for that. I've seen LED bulbs with large heat sinks, but I personally have no experience with them. Where I was/am going with this 'heat' thing is to compare the radiated heat of a PAR/HAL and/or HR lamp to the equivilent lumen output LED.

Posted By: boora2 Re: exploding bulbs - 07/17/13 10:03 PM
Made in China.
Posted By: schenimann Re: exploding bulbs - 07/19/13 04:55 AM
I am going to try to sell them on changing over to LED bulbs. I think they will find the investment worthwhile. That being said, in this world of LED manufacturers where is the quality?

I just installed 40 par30 LEDs from TCP in a new house. I only install quality products and want to know what will be best for them. TCP, Verbatim, Sylvania, etc?
Posted By: NickD Re: exploding bulbs - 07/29/13 11:46 PM
Originally Posted by HotLine1
Alan:
Thanks for that. I've seen LED bulbs with large heat sinks, but I personally have no experience with them. Where I was/am going with this 'heat' thing is to compare the radiated heat of a PAR/HAL and/or HR lamp to the equivilent lumen output LED.



The reason for the heatsink is all physics. You have a fixed unit quantity of heat... say 10 watts. Apply that heat to a small 10 gram mass... it'll be HOT. Apply those 10 watts to a 10kg mass... you might or might not feel a difference.

The heat sinks are large mostly because there is no accompanying fan, so they have a very high surface area to encourage convection currents over the fins.
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