catastrophic bulb failure

[Cybrvanr]

I had a light bulb blow in the shop today that really suprised me. When it blew, the bulb went off like a cannon in a bright blue flash! The bulb itself shattered, throwing glass all over the place. It also tripped a circuit breaker, and burned out the dimmer switch it was attached too. Was pretty embarassing going into the demo room to show off a video editing system, and having to troubleshoot the lighting system in the room (and clean up all the glass that came down on the equipment!

What the heck would make a light bulb go off like a bomb like this?

 

[DADoES]

Contamination? Mechanical stress? Current surge?

I've experienced several explosions with the halogen arc-lamps in movie theater projectors -- it's quite traumatic for the mirrors and reflectors.

 

[frigilux]

Yikes! I've only seen an incandescent bulb explode if it's gotten wet while it's hot. Was it a halogen bulb? Those suckers get so incredibly hot it's a wonder they don't explode regularly...

 

[toggleswitch]

Normally light bulbs, or LAMPS as they are properly called *cough* [the Brits are watching) IMPLODE [I thought] due to partial vaccum.

Anyhoo glad no-one was hurt.

All kidding aside, so many things in my world failed mechanically today. Must be Mercury retrograde or a bad aspcect somewhere in the planets.

 

[brisnat81]

Try Globes on for size instead of Lamps

Try calling it a globe rather than a lamp.

A lamp over here tends to be the device that the globe goes in.

 

[tolivac]

What kind of bulb was it-If its in a television or movie studio-these bulbs are often run at higher voltages than they are rated for to get the proper light color "temparature"the hotter the filament runs-the "cooler" the color temp-Ie more "blue" in color.This matches the reference color temps (6500 degrees Kelvin) film and tv cameras are calibrated for.The bulbs run very hot and under positive pressure.If they is any sort of fault in the envelope(bulb) it will blow-Just like xenon sealed arc bulbs used in motion picture projectors or searchlights.These will blow if they is a fault in the envelope,the bulb gets overheated(say a blower or exhaust duct problem)or some kind of fault in the ballast circuit-for discharge bulbs such as xenon projection lamps,or HID bulbs such as metal halide-the white light emitting bulbs found in some building lights or some parking lot lights.also the metal halide bulbs will generate a "warmer" colored light as they age-if they get too aged-they can blow-have seen it happen-a nice "POP" when they go.The arc tube inside the bulb shatters-sometimes with enough force to break the outer glass bulb.

 

[tolivac]

Another thing on the lamp failure-If the bulb is a quartz glass envelope(Halogen bulbs without an outer glass bulb)and the xenon projection lamps-if someone handled the bulb with their bare hands and didn't clean the bulb after handling-that could cause it to explode-the salts from your skin attack the quartz bulb as it heats-causing a weak spot in it-thus its stressed to the point of "BOOM"!!These should be handled with cotton gloves-a clean rag-or the wrapper the bulb was packaged in while installing it in the fixture or lamphouse.The bulb should be wiped off with a clean rag dampened with alcohol-this washes off the body salts.also no flammable materials should be under such bulbs-if it ruptures the fragments are hot enough to cause a fire.Most fixtures or lamphouses that use such bulbs contain the fragments in case of rupture.

 

[tolivac]

Another thought-xenon bulbs are under positive pressure even when turned off-Their pressure rises even more after they are on and heated up-ie the projector lamps,searchlights,sun similators.That can explain the explosions as those go from some sort of fault.The xenon bulbs are dangerous to handle even when cold.they are usually packaged in some sort of hard plastic case that you remove after installing the bulb.You also should wear a face mask,heavy gloves and a flak coat when replacing xenon bulbs.NASA usues a lot of xenon bulbs in the sun similators for testing spaceships,spcesuits,etc.Paint manufactuers use them for testing paints and finishes-The xenon bulb generates high amounts of UV light.They may even find their way into some tanning machines and booths.

 

[Cybrvanr]

Nope nothing exotic really. This was an ordinary round incandescant bulb. It was in the row of track lights in the control room right above the console. You guys are right though, I would have expected that from a lamp in the actual studio! Some of them are quartz-halogens. My favorite studio lamps though are the new high intensity fluorescent lamps. They are only warm to the touch, and use 1/5 the amount of power the halogens do! The nice part too is that one can dim those, and they don't change their color temperature!

Hmm...water is another thought though, but I didn't SEE any leaks. We had some snow here over the weekend, and it could have been melting and dripping down on the fixtures.

 

[toggleswitch]

You say to-MAY-to- but I say to-MAH -to

Said: A lamp over here tends to be the device that the globe goes in. (You put you globes in something?)

The lamp goes in the lampholder.

-Well, all this per the (US) NEC (National Electric Code).

(Same set of regs in UK is => IEE wiring Regulations, perhaps this is the *Institue of Electrical Engineers*? )

http://members.tripod.com/~masterslic/FAQ-2/23.html

 

[tolivac]

I like the idea of the flourescent studio lighting-any info on these-That would be a boon to the studios-would also cut the air conditioning reqirements-less power consumed by the lamps and the HVAC system.Thats interesting it was an incandescent bulb-haven't seen one fail like that.Most incandescent bulbs have an internal fuse in them-it blows in case a broken filament shorts to another part inside the bulb.The lead wires in the bulb can act as a fuse.

 

[tomturbomatic]

Once, my brother blew his clarinet at a light bulb in a table lamp when he did whatever you do to drain the condensed water vapor and the bulb went out with a big bang. We never told mom just why the lamp failed. I have a greenhouse lighting fixture with both sodium vapor and metal halide lamps for growth and bloom production. There were lots of warnings about handling and using the bulbs and a heavy glass safety shield between the bulbs and the open side of the fixture. The images of falling glass igniting stuff were pretty scary.

 

[toggleswitch]

Early fixtures upon conversion from gas lighitng to electric

Typical early NYC fixture when lighting went from gas to electric.

Normally, these have pull-chain switches This method avoided having to chop the walls to add switches. And control of lighting was at the fixture before electricity!

One typical "feature" was the space in the middle (comes lower into the room) to accomodate the gas pipe that protruded into the room.

Theses were mounted to a type of gas-pipe cap that had on top of it a female thread for an electical nipple (type of screw with thread only no "head"). BEHAVE!

 

[toggleswitch]

That was a plain one, here is a fancier one.

Please excuse the messy paint-job. If you only KNEW the neighborhood these were seen in! OH MY!

 

[toggleswitch]

Even the simplest fixture had the recess for the gas pipe!

[This is why landlord's don't like you to have a washer! :-(
Right under a hook-up and allocated space].

 

[toggleswitch]

Now that is the way to get you globes / light bulbs / lamps /photo-emitters wet and watch them explode.

 

[polkanut]

RE: Post #109939, OOPS! :-(

 

[toggleswitch]

Here is the above apartment.

Looks like SOMEONE got their washer confiscated!

The fridge is to the left (not pictured)
Looks like two valves on the COLD water line and that the ice-maker feeds throught a rubber hose. Is that considered potable water?

It NEVER ceases to amaze me at the stupidity I see....

 

[toggleswitch]

Soemone else got to KEEP their washer.

Is it the brand that I think it is? GASP!

(Pay no attention to the rainbows...this is not a symbol of who lives here..TRUST ME!)