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Topic: So What Do You Do When A Bulb Explodes?

Pete Naples
Phenomenal Film Handler

Posts: 1565
From: Dunfermline, Scotland
Registered: Feb 2001

posted 02-28-2002 09:55 AM

One of my Super Lume-X sites uses, has always used, and will always use the 'emergency ignition' button. The T&R rectifier they have only gives about 80v OCV, which won't flip the Zener, I offered to change the Zener, but they were happy with pushing the button, they have done this for the last ten or more years, bulb life has never been a problem, they can run a 2Kw to well over 2500 hours, they don't as a rule, but did it a couple of times to prove the point. In short the manual ignition won't adversely affect bulb life is used properly.

I've heard varying opinions on how much life each strike takes, anything between 30 mins and 2 hours! Look at it this way, the striker produces a very high frequency HV pulse, We strive to get the AC ripple from our rectifiers down as low as can be, as we all know that AC ripple causes flicker, but it also causes electrode damage to the lamp, so hitting in with 50,000v of RF doesn't do it any real favours either I would think.

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Joseph Pandolfi
Expert Film Handler

Posts: 213
From: Milford, CT.
Registered: Nov 1999

posted 03-01-2002 01:34 PM

I almost had one blow Tuesday night (2/26) waiting for Crossroads to end when my hand almost got burned resting on a Christie Xenon-lite 2Kw lamphouse. The stack fan quit during the show. I quicky grabbed the spare rectifier squirrel cage fan and mounted on top of the lamphouse and plugged it in when the show ended. The booth temprature shot up about 10 degrees. Then I had to run one more show after that.

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Darren Briggs
Master Film Handler

Posts: 371
From: York, UK
Registered: Dec 2001

posted 03-02-2002 04:01 PM

Xenons blowing can make you very weary about lamps and lamphouses.
As mentioned above by Leo, (he was my chief when this happend) our blew due to us over running the lamp, we had a amazing picture and we were in the middle of sorting out why lamps only lasted 1000 hours before you couldnt see the flame in the xenon due to the envelope being black, then the lamp went whilst i was stood at the left hand side of the lamp house.
Another college fled the projection box whislt the lamphouse started to look more like a steam train with black smoke coming out from the extract fan! I dashed to the distridution panel to shut of the power, then we all went to the pub downstairs to calm our nerves for an hour.
It can be a scary noise when one blows and the mess it can make is unbeliveable. Both in and outside of the lamphouse.

I know of people who say you don't need to worry about them exploding and face masks etc just get in your way. But I would say don't even touch a lamp without protection. Leo had one blow in his hands when putting it away in it's box. Saying that it was one that we had 'nuked' with 100 amps for 1000 hours.
Luckly it was just the mirror which got marked in our lamphouse.
(Cinemeccanica Zenith 2000H)

I can make 2k lamps last 3000 hours in our other 3 Cinemeccanica CX16H's by rotating every 500 hours.Thats twice as long as there warranty. How does everyone else do??

Darren

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Leo Enticknap
Film God

Posts: 7474
From: Loma Linda, CA
Registered: Jul 2000

posted 03-04-2002 02:07 AM

Thanks Darren...

One other point: when you do clear up the mess, be sure to wear the full 'Iron Giant' costume (i.e. jacket, visor and gloves) when hoovering up the mess and cleaning out the lamphouse, even when dealing with cold lamp debris. I'd also be inclined to wear a face mask too (like the smog masks over your mouth which some cyclists wear). The quartz envelope can shatter into really tiny fragments and if they either pierce your skin or are accidently inhaled then at the very least it'll be extremely painful, and could actually do you some serious damage.

BTW, the anode cores make great paperweights!

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Phil Hill
I love my cootie bug

Posts: 7595
From: Hollywood, CA USA
Registered: Mar 2000

posted 03-04-2002 03:27 AM

For a period in 1997, I blew up nine 7kW bulbs of several manufactures in a period of 2 weeks. I was trying to find out the why a certain manufacturerer's (no longer in biz)lamps were failing prematurely. After the explosions, I then tuned the theater's audio systems...

My peers were affraid to be near me when I did the tests and called me "killer".... Since I was head of engineering, I guess the title fit!

>>> Phil

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Bernard Tonks
Jedi Master Film Handler

Posts: 619
From: Cranleigh, Surrey, England
Registered: Apr 2001

posted 03-04-2002 05:25 AM

My worst explosion was with a 2k Osram during a show which shattered the mirror into a million pieces and bent the fan axis beyond further use. The noise of the bang and plume of black smoke was unbelievable and I did in fact suffer from shock until I was able to move the programme to continue on No 2 projector. I sent the remains, the anode and cathode being green in colour to Osram although the bulb had clocked just 700 hours, they did send a free replacement. Our last bulb just died in silence and intact, average lamp life here is 2,500 hours.

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