ECN Forum Forums General Topics of the Trade General Discussion Area exploding bulbs

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?

I've heard of lamps burning out prematurely, but exploding?? 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?

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.

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.

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!

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?

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.

In my experience 60W equivalent LEDs tend to be 6-9 W.

Tex:
Are you saying that the heat is only 6-9 watts??
I see a lot of LED lamps that have IMHO large heatsinks??

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).