Automated Fixtures Moving Light Shrapnel Hazard

DiscoBoxer

Active Member
Today during service, one of our Elektralite MY250i units had a catastrophic bulb failure. Midway through worship, heard the pop, light goes out, small smoke cloud, and woman underneath the unit looks up naturally and gets a shard of bulb glass that lands on her forehead. Also shards all round her and other folks. Thank God nothing went into her eye when she looked up and nobody was injured.

This is the first time I have experienced this and my question is, is this common?

What is the root cause, sudden temp change to the glass?
 
Today during service, one of our Elektralite MY250i units had a catastrophic bulb failure. Midway through worship, heard the pop, light goes out, small smoke cloud, and woman underneath the unit looks up naturally and gets a shard of bulb glass that lands on her forehead. Also shards all round her and other folks. Thank God nothing went into her eye when she looked up and nobody was injured.

This is the first time I have experienced this and my question is, is this common?

What is the root cause, sudden temp change to the glass?

Moral of the story: LED technology. :p
 
Moral of the story: LED technology. :p

LMAO! It's funny because we just picked up a few 36x3w fixtures that I have grown quite fond of. Unfortunatley, I haven't found a unit that can do what our yokes can do....in the price range. :lol:
 
Is it common that lamps explode? Not terribly. Does it happen often enough? Yeah, every so often. Especially as HID lamps rack up more hours on them, they become brittle and the chance of explosive failure increases.

It should not be considered acceptable that a fixture be built such that it can allow a relatively common failure type to result in shattered, possibly molten pieces of what I can only presume are quartz and glass onto anyone below the fixture.
 
Never seen that happen to a moving head. Seen lamps blow, but never had a fixture blow apart because of it. It can happen to a par can, but safety screens pretty much take care of that. I would take the unit out of service and all units like it and send it back to the manufacture. Having never heard of the company that made the fixture, I can only assume that quality control is not a strong front of the company. You got what you paid for, be glad your not getting sued.
 
Never seen that happen to a moving head. Seen lamps blow, but never had a fixture blow apart because of it. It can happen to a par can, but safety screens pretty much take care of that. I would take the unit out of service and all units like it and send it back to the manufacture. Having never heard of the company that made the fixture, I can only assume that quality control is not a strong front of the company. You got what you paid for, be glad your not getting sued.
I had never seen it either until last week. It didn't "blow apart" but we had a Studio Color that had the same type of lamp failure on power up. Fortunately, all the glass stayed inside the fixture, but it's going to be a pain to clean it all out. We got most of it, but it still sound a bit like a rain stick when you move it. Anybody got any suggestions on how to get all those sand-like particles of glass out of the fixture?
 
The glass from bulb failure will only actually fly out of the very worst of moving lights. Most every moving head that I've teched other than those Elektralites has a lamp housing that won't let this happen. I've seen lamp explosions in in a couple of moving lights, including MAC700s (happened right in front of me while I was testing them, definitely made me jump). The MAC700 lamp explosions (there were 2) were seemingly because the fixtures had only been used in one tilt position on a show, and the lamps were rather old. One of the electrodes fell off, hit the glass, and that's when the lamp blew out making a nice little hole in the glass. However, this is most often caused by lamps that somehow have finger grease or another oily deposit on the surface of the lamp.
 
Moral of the story: LED technology. :p

No, moral of the story: Don't buy cheap crap.

(And yes, I know that is not always possible, but LED's are not the end-all be-all of lighting technology. There will be some things that we can never do with LED's. My apologies for the soapbox rant, and to nuggety - I'm hoping you truly were joking.)
 
How many hours did that lamp have on it? As mentioned earlier, arc lamps that are beyond their life expectancy carry a greater risk of explosion.
 
No, moral of the story: Don't buy cheap crap.

(And yes, I know that is not always possible, but LED's are not the end-all be-all of lighting technology. There will be some things that we can never do with LED's. My apologies for the soapbox rant, and to nuggety - I'm hoping you truly were joking.)

No; buy all the cheap crap you want, but don't hang it over people...

Though I suggest not buying cheap stuff. If you can't afford a good tattoo artist, don't get the tattoo...
 
No; buy all the cheap crap you want, but don't hang it over people...

Though I suggest not buying cheap stuff. If you can't afford a good tattoo artist, don't get the tattoo...


Very well said, Arthur. I must concur-

(Grandma, why do you have a condor tattooed on your saggy arm? Child, THAT was a butterfly!)
 
The fixture itself did not have any damage when we opened it up today. It will be fun cleaning all the shards of glass within the housing. Like someone stated earlier, it sounded like a rain stick when moving the fixture around.

The yoke was moving when the bulb failed and it appears as though the glass came out of the vent for the fan. Once it blew, we immediately pulled power from the unit and later removed it from the light truss.

As for the "cheap" statements, I get it, but truly not every venue enjoys the luxury of large budgets and we do the best we can with what we have to work with. For the price point (under $2k), I think these fixtures are fantastic.

The bulb had approx 1700 hrs of operation. Elektralite states 2000, but what have you guys seen in the field for average bulb life?

I lack experience with various brands of moving fixtures. Do all of the higher price/quality brands have an enclosure design that prevents the shards of glass from falling out of the fan port or is this something that is possible in almost all fixtures if the light is moving and flinging glass around in side the housing when it explodes. Please understand that these are genuine concerns and are not intended to be condescending. Thanks!
 
I'd look at the unit to see if there is any way to add a thin wire mesh inside the vents to stop this from recurring should another lamp have a non-passive failure. You need to be sure that it is not obstructing ventilation, but I have seen some shops to similar things to keep stuff out on BMX/ monster truck/ ect type shows where it's totally possible to find small rocks in the lights.

This is just my personal recommendation, not anything from LAVA by the way.
 
The yoke was moving when the bulb failed and it appears as though the glass came out of the vent for the fan. Once it blew, we immediately pulled power from the unit and later removed it from the light truss.
This is a good point. I'm not 100% sure that, had my HES fixture been moving when the lamp blew, it wouldn't have let glass out of the housing.
Is anyone else sure that more expensive lights won't allow glass out?
 
As for the "cheap" statements, I get it, but truly not every venue enjoys the luxury of large budgets and we do the best we can with what we have to work with. For the price point (under $2k), I think these fixtures are fantastic.

I am speaking here from my experience, so keeping in mind that Elektralite is still in business, I can't be right across the board. But I will say that the Elektralite fixtures that I have seen and those that I have heard of (3 people that I can remember right now have told me about how much their Elektralite fixtures don't get the job done) have not been a good deal given the price paid on repairs and issues had in normal use. I've also seen some errors and issues on Elektralite fixtures that no moving light should ever have. I'm not saying that Elektralite is across the board bad, but I really haven't heard much good about them.

In the future, if you end up purchasing any more moving lights, I'd say look at Elation - they have some good stuff at decent pricepoints, and in my experience and from people that I have spoken to (one of whom kept his 4 Design Spot 250s in a band's van without cases and toured with them and they worked fine) it stands up much better to a life of extended operation.

The bulb had approx 1700 hrs of operation. Elektralite states 2000, but what have you guys seen in the field for average bulb life?

I'd pull them closer to the 1500 mark, mainly because I don't like to see color temperature deteriorate too much. One thing that I have seen with mover lamps of the MSD/MSR type that get left running too long is that the inner envelope of the lamp begins to expand. I have seen a couple of lamps where the inner envelope was almost touching the outer envelope, which (especially if the fixture was moving) would probably have ended with catastrophic death for the lamp. All of the lamps where I've seen this (and it's been quite a few now, usually in fixtures that people bring in for service) have been very low in color temp and rather dim for the kind of lamp that they are.

I lack experience with various brands of moving fixtures. Do all of the higher price/quality brands have an enclosure design that prevents the shards of glass from falling out of the fan port or is this something that is possible in almost all fixtures if the light is moving and flinging glass around in side the housing when it explodes. Please understand that these are genuine concerns and are not intended to be condescending. Thanks!

I have seen wire mesh over the fans in a couple of fixtures, I have seen double-fin vents that catch broken glass in a number of fixtures, I have seen vents that bring air from the front of the fixture to the back of the fixture for cooling in a couple of fixtures, and I have see massive heatsinks with no exit points in other fixtures (fixtures that look like they have lateral "fins" in the back fall in to this category). But I haven't seen many fixtures at all where the catastrophic failure of the lamp hasn't been taken in to account.

Many fixtures also have the UV glass positioned in front of the lamp housing so that the glass cannot exit in to the rest of the fixture, but in some cases I have seen this shattered. For glass to exit a Studio Color or Studio Spot (575 series), it would have to get through all the bits and pieces of the assembly to the front of the unit and fall out around the lens. Hopefully the operator would be able to kill the fixture in the significant amount of time that this would take. If the fixture was not moving, there's very little chance of this happening.

Try chauvet LED moving heads.

I don't know if the OP would be able to use a fixture that was around the output of a 250w halogen lamp, but I will say that none of them come anywhere close to the output of an MSD250. For that you need at least a 90 watt LED engine from a respectable manufacturer, like Lumileds, CREE or even Edison. (EDIT: I should clarify that I'm talking about the moving head "spot" fixtures here, that is the fixtures that are hard-edge and can project gobos. Chauvet, ADJ and Elation have moving head wash fixtures that could challenge or in some cases surpoass an MSD 250, but the OP here is talking about a spot fixture).
 
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Many higher end fixtures these days have air filters at the intake and outflow vents on the fixture. These filters not only would help contain a lamp failure, but also prevent foreign material from contaminating the inside of the fixture and lamphouse. Additionally, most of the MLs that I have worked with also have lamp housings where it would be quite difficult for particulate matter to get in or out of the housing.

When you look at lamp hours, you have to account for the number of lamp strikes that you have made over the course of the life of the lamp. A good rule of thumb is that each strike is equivalent to about an hour of burn time (due to the strain of striking an arc). So, if your hour counter read 1700 hours, you were probably very close to average life expectancy of the lamp when you account for strikes. I usually plan to change a 1000 hour lamp at about 750-800 hours. While sometimes it is possible to eek out more life from a lamp, you do start to loose things like intensity and color temperature, and in the end, the longer you burn a lamp (especially if you pass the average life rating), the more you risk a catastrophic failure. So, better safe than sorry. I would rather buy a $120 lamp than pay big bucks to repair a fixture.
 
I guess I'm lucky in that I've only experienced one lamp explosion (happened to be in an automated Xenon fixture, well below rated hours, and on the first strike of the day. Made a huge mess, but didn't damage anything).

A colleague tells me that, over five years, he has experienced three lamp explosions, in two fixtures (a projector and a followspot) using a 2500W MSR lamp.* In all instances, the shrapnel was contained within the lamp house, but reflectors and lenses were damaged. Although the lamp is rated for 500 hours, he regularly changes them at 450 hours.

*In all three cases, the lamps were the same brand, and early in their anticipated lifespan. This prompted him, and others here who use the same fixtures, to change brands. It may have been a bad production run, but that brand of that lamp will never be trusted again.

Note this exploding phenomenon is not limited to automated fixtures. See
http://www.controlbooth.com/forums/lighting-electrics/16396-exploding-par-can.html
http://www.controlbooth.com/forums/lighting-electrics/12040-epic-fail-why-fels-bad.html
 

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