When a fuse blows in an electrical appliance, you don't (if you've got any sense) just replace it and carry on regardless. You attempt to identify why it blew, because 9 times out of 10 the fuse blowing is a symptom of an underlying problem (the tenth time it's an innocent power surge on the incoming supply, but never rely on that being the case). Replace the fuse without finding out what caused it to blow, and at the very least you'll get the same result again, but you also run the risk that next time the damage will be more severe.

The same applies to lamps - the main difference being that blowing up lamps all the time is pretty expensive compared to fuses. I'm assuming that your lamphouse mirror is still in one piece and that the igniter unit appears to be undamaged. In this case then at the very least inspect all circuit boards, connectors &c. visually for any obvious signs of damage. If you can't identify any obvious reason why it blew (e.g. the extract fan failed, or it's done about 30,000 hours), I'd suggest calling an engineer in.

The one exploding lamp I ever had when I was a projectionist was eventually traced to a faulty ammeter - basically, it was saying 60 amps when in reality and without knowing it, we were running it at 100-110. Needless to say this was not obvious when we cleared up the wreckage from the explosion, but if we hadn't kept investigating until we got to the bottom of the matter we'd have blown up another lamp.

So my advice would be, make every effort to find out what caused the explosion.

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 585-477-5325 Cell: 585-781-4036 Fax: 585-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Course these things always happen on my day off, so the bulb's already been replace. Apparantly the mirror was intact but the douser was toast. Oh well, geuss you really don't need that anyway, right?

Sometimes I don't even know why I try.
 

I second Leo's comment, these things do not randomly explode, besides the obvious mechanical damage to the mirror etc, there's got to be some underlying cause.
 

This topic has been discussed before. Leo and John are also correct.

To add to the list:

Bulbs should be inspected for damage or defects prior to installation. Also, applying excessive torque while installing may damage the quartz (bulb manufacturers talk about this)

Another possibility could be that the lamp house door was opened prior to the required cool down time.

I only had a bulb explode on me once. This is when I was lifting a brand new Perkin Elmer out of its box, it exploded in my had and made me jump a little . Thank God I was wearing the required safety gear and the bulb still had on it's protective wrapping!
 

1) The autostrike board in this lamphouse (Strong Super Lume-X) has been non-functional for quite some time, thus necessitating the operator to always manually ignite the lamp by depressing the strike button at the top of the lamphouse. If I understand things correctly this put stress on the bulb. The parts to fix this have been sitting at the theatre for quite some time, but our service company almost never comes out on regular service calls.

2) I suspect the ampmeter was defective-as was Leo's case. It reads 60 Amps no matter how high or low the power supply is turned up. I brought it up to my tech during the last service call, but he said it was fine.

*Stalks off muttering about how no one ever listens to him*
 

The ammeter mis-calibration has merit. I have seen some that were as far off as 15 amps.

Most service techs will not sweep out the lamphouse. Nor will they change the bulb. Reason is, if the bulb blows up, there is just too much "finger pointing" on whose fault it was.

If MTS does your service work, it is their policy NOT to change xenon bulbs. I have to side with MTS on that one. Don't get angry with your tech. He is simply following orders.

Paul

Why?

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.
 

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
 

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!

>>> Phil