# Catastrophic lamp failures



## icewolf08

Last night during the show we heard an unusually loud gunshot like sound. It actually caused an actor to do a doubletake. It seemed too loud to be a lamp failure and we didn't notice any dark spots on stage. Well, guess what we found during channel check today:



This is the front of the lens tube and lamp from a Strand Century Axial 6x9


Here is the back of the lens tube


And the lamp

Needless to say, as the LD used every 6x9 and 36˚ unit in my inventory, we will have to come up with a solution for tomorrow's show.


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## Wolf

what would have cause the lamp to fail like that, simple as just someone had touched it?


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## Spader

Yeah...FELs go out with a bang. At our theatre here, we have an inventory of about 20 S4's and 30 Strand Lekos (Which use FEL lamps). Whenever the Lekos go out, everybody knows it. When the S4's go out, no flash, no sound, no nothing.

I just remembered:
I have a PAR64 lamp to replace this weekend because it went out this past weekend. It was really cool when it did go out, because suddenly this bright purple light filled the room.


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## Footer

I had one go out a few years ago in a 360q. It was during tech, so I was asleep in my office backstage. I hear the "shot", thought we were under attack. Then I get the page backstage saying we lost a lamp. I had to take the fixture down and completely tear it down to get all the glass out. We didn't break a lens though, thats a first time I have seen that. I have seen a Par56 explode... that was "cool"


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## icewolf08

Most of my FELs have been replaced with HX-755s, but apaprantly I missed a couple (or at least one).


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## JD

Odd that the shatter pattern is from the front of the lens inward... Sure it wasn't really a gunshot?


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## icewolf08

JD said:


> Odd that the shatter pattern is from the front of the lens inward... Sure it wasn't really a gunshot?



The shatter patter is on the inner of the two PC lenses in the tube, so it is from the back.


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## JD

icewolf08 said:


> The shatter patter is on the inner of the two PC lenses in the tube, so it is from the back.



Feisty little thing!!


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## derekleffew

Alex, why does there appear to be about a 1/8" hole in the lens tube's right colorframe clip? Picture #1 also shows the silicone lens mounts not properly evenly distributed around the circumference of the lens.

I've only cracked the rear lens in 4 1/2 x 6 1/2 fixtures using FELs. (And 360Q-6x9, but that's wrong in the first place.) Such a catastrophic failure was most likely due to an impurity in the envelope, and not an inherent flaw in the lamp design. I have had HPL575s and 750s exhibit a similar end of life, but no cracked lenses.


> Needless to say, as the LD used every 6x9 and 36˚ unit in my inventory, we will have to come up with a solution for tomorrow's show.


Buy a new 6x9 lens for $65, or hang a 6x12 approximately 1.5 times further away.


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## icewolf08

derekleffew said:


> Alex, why does there appear to be about a 1/8" hole in the lens tube's right colorframe clip? Picture #1 also shows the silicone lens mounts not properly evenly distributed around the circumference of the lens.
> 
> I've only cracked the rear lens in 4 1/2 x 6 1/2 fixtures using FELs. (And 360Q-6x9, but that's wrong in the first place.) Such a catastrophic failure was most likely due to an impurity in the envelope, and not an inherent flaw in the lamp design. I have had HPL575s and 750s exhibit a similar end of life, but no cracked lenses.
> 
> Buy a new 6x9 lens for $65, or hang a 6x12 approximately 1.5 times further away.



I never noticed the hole. I do the best I can with the manpower and budget I have to keep these fixtures running. They do pretty well, however, they have seen better days. I have done the best with the gear that I inherited when I took this job. Every year I take the worst of the fixtures out of service and replace them with Source Fours (about 4-10 each year depending on funds). Once out of my inventory, I give them to the Theatre Department here at the U. Most of them work very well despite the fact that they look like they have been Frankensteined together!


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## ship

Or at least take these photos to those that do the budget and say you would like to go GLC or GLD for high output or GLA or GLE for long life with similar ouput. It's a safety issue as long as you don't tell them it's more of a fluke of filament failure and rare. 

That's an amazing "Kill Roy Was Here" failure as I named such a thing when the filament of the lamp explodes out the side of the globe as if gunshot with the glass lingering in cooling as if held in slow motion in how it bent out to reflect the escape of the filament. 

Most likely on the opposing side of the lamp you will also see a puckering of the glass as the gasses in the lamp were sucked out. This shape of the puckered/sucked in glass in the case of an incandescent lamp I noted with a filament gunshot thru the globe, formed a "Kill Roy Was Here" shape on the sucked in side of the glass. Thus the name for it I have.

Most likely, it wasn't due to touching the lamp as initially assumed, just normal halogen cycle in depositing tungsten particles on the hottest part of the lamp - the center of the filament, and for some reason as opposed to a normal failure, that filament in where it broke and going arc lamp or as I call "super nova", it flying out the side of the globe in that instant of while it's super nova. Given a halogen effect, that doesn't mean that spent tungsten particles near the edges of the hangers or lead in part of the resistant filament gets a re-deposit of tungsten on it as spent, instead it often just goes to the center of the filament in while it takes longer on halogen lamps to wear out than on non-halogen, incandescent lamps to wear out, still towards the filament supports or lead in wires of a halogen lamp, it can still wear out without replentishment. This area in a micro second often is also in normal and not shock where is where once broken an arch of current will develop until the resistance to current flow is too much to continue with that much brighter now in being a arc light intensity. 

Given the power of that instance of it being an arc light, there becomes at some point so much pressure that there can be a blow out of the filament given all support and lead in wires for it have not had sufficient replentishment of them so as to support them while going super nova arc lamp as it were. At that point that filament resistor following the arc of current no doubt starts flopping wildly in explosion and should it escape during this also period of intense heat, that's about the end result. If nothing else, that's a lamp that lived well past it's expected lamp life if not got a shot of voltage in failing. Normal failure just under conditions where the amperage applied to it was sufficient to continue completing the circuit even if no longer connected to power source. Bang! within a micro second that filament escaped and the light goes out.

Rare and wouldn't be worried about happening, nor in this case it would seem did the fixture other than protect the audience or talent below as designed should it happen. Wouldn't tell the management it's other than a problem and we need to change lamps given the lamp in use, but realistically there was no safety hazzard. More just an excuse used to change to a better lamp.

The FEL ain't rated for most fixtures and even if rated for it, your's ain't efficient in using them as opposed to other lamps more recent to the market. It's a selling point for more efficient lamps budgeted for next year.


Go with it in selling it even if not normal to be a problem. In the end... Killroy Visited You as it were. It's rare and spectacular ain't it.

Get rid of them FEL's for other reasons than this filament spectacular escape.


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## mrb

I bet this was a combination of factors, the lens not seated properly in the tube with the misplaced silicone pieces + tremendous heat from using 1K lamp = lens under stress, and the exploding lamp was enough to make the lens fracture. Kind of like how a piece of tempered glass under stress will explode with a gentle tap.


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## church

unusual failure because these fixtures use two lenses with the curved surface touching. The 6*9 barrel actually uses two 6*9 lenses which at their centre are approximately 1.75 inches thick. However lenses used in stage fixtures include voids from the manufacturing process which don't affect their performance in this application. these voids in conjunction with stress from uneven lens mounting and even micro stress cracks from the fixture being moved and knocked may create the conditions for this type of problem. 

If I was doing a failure analysis on this my hypothesis would be that as the shock wavefront resulting from the expanding halogen gas released by the rupture in the quartz envelope expanded through the focal gate and reached the first lens causing this lens to shatter and because there is only about 1/8 of an inch between the lenses one or more bits of gllass hitting the second lens causing it also to shatter. I have seen this type of failure on optics before in optical instruments when we have applied accoustic shock waves to them.

Fortunately the reflector is metal - if this had been a S4 you would probably also need a new reflector.

This can happen with any halogen lamp - the manufacturers include a caution on the lamp failure in every box. A FEL, GLC, GLA, HPL and any other halogen lamp can all produce a failure like this - fortunately it is very rare. All the halogen lamps contain a gas at a similar pressure - if they don't they don't work because the halogen cycle controls this. The variables include the filament temperature, filament size, quartz envelope size

Replace the lenses and the lamp and return to service.

I recently cracked a lens in a colortran zoom using an FEL. Brought the fixture indoors after it had sat for a few days in my van at -20 degrees centigrade, clamped to a pipe and after 30 minutes turned it on and heard the crack after only five minutes of operation. Differential rates of expansion of materials cause real problems when fixtures are cold like the one I had. Normal room temperatures are not normally a problem. But the failure was caused by my not allowing enough time for the fixture to reach room temperature before turning it on - not that the FEL the fixture or the lens was faulty.


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## icewolf08

ship said:


> The FEL ain't rated for most fixtures and even if rated for it, your's ain't efficient in using them as opposed to other lamps more recent to the market. It's a selling point for more efficient lamps budgeted for next year.
> 
> Go with it in selling it even if not normal to be a problem. In the end... Killroy Visited You as it were. It's rare and spectacular ain't it.
> 
> Get rid of them FEL's for other reasons than this filament spectacular escape.



As I mentioned, it is probably a fluke that this unit still had an FEL in it. I have only stocked HX-755s for these fixtures for the past two seasons (mostly thanks to your recommendations). However, I would take this to management with the pitch that the fixture is at fault to see if they would give me the money to replace the last 45 in my inventory. 

And yes, other than this being very cool and kinda pretty, it was certainly a great example to use as education for my crew. I have seen some pretty spectacular lamp failures, but most of my crew had never seen something like that. Par of my wants to fill the lens with epoxy and keep it as art (and an educational piece).


church said:


> This can happen with any halogen lamp - the manufacturers include a caution on the lamp failure in every box. A FEL, GLC, GLA, HPL and any other halogen lamp can all produce a failure like this - fortunately it is very rare. All the halogen lamps contain a gas at a similar pressure - if they don't they don't work because the halogen cycle controls this. The variables include the filament temperature, filament size, quartz envelope size
> 
> Replace the lenses and the lamp and return to service.



I am aware that this can happen to any lamp, I have seen HPLs go out in some pretty spectacular ways. It is fortunate that it is rare, it just seems less rare in FELs. As for replacing the lens and returning to service, that is easier said than done on account of I have no more 6x9 lenses. It isn't worth me buying a lens for these fixtures as I am already planing to retire and replace 4 of them. I do have 6x12 lenses for them, so this unit will live to see another day. If this had happened to a source four, I would have a new lens here tomorrow, these fixtures just aren't worth much more than the time it takes us to service them each year.


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## JD

What I remember with those FELs is that the filament would sag until it was close to the quartz, which would start to bubble out. Use to see the same thing in some par bulbs that didn't use center supports. I used a lot of VNSPs where it is very visible because of the clear front. I can remember rotating lamps whenever I saw any sag starting. Can't be sure it ever extended any life and I never really kept track.


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## cdub260

icewolf08 said:


> Par of my wants to fill the lens with epoxy and keep it as art (and an educational piece).



Do it. This would be a cool thing to keep around, especially if you make the fixture a part of that art/educational piece.


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## lieperjp

cdub260 said:


> Do it. This would be a cool thing to keep around, especially if you make the fixture a part of that art/educational piece.



Make it into a table lamp! Erm... maybe not.


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## derekleffew

Alex, you need to post your lens picture here.


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## church

When I was preping some fixtures to go out on rental I found a HPL 750 about to self destruct lloked very much like Derek's above but with a bubble in the side of the quartz envelope. The lamp was still working but I removed it and stuck it in the garbage before it destroyed a lens or reflector. As I pulled it out the envelope seperated from the base. This was a new lamp with less than 10 hours on it. When I checked the lampholder I found one of the contacts was also burned to a crisp.


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## thatactorguy

derekleffew said:


> Alex, why does there appear to be about a 1/8" hole in the lens tube's right colorframe clip?



My guess is that the hole was for a self-threading screw or some sort of pin or clip to help hold the gelframe in place if the instrument were hung in such a manner that there was a chance of the frame coming out. Just a thought...


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## Esoteric

Well, I had that happen during a show. Only it totally blew the glass out and on to the actors who were having an intimate moment on stage, raining glass down on them. They didn't even flinch.

Mike


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## venuetech

I was doing a lamp check once when one foh unit failed just as i was about to move on to the next channel, it had burned around thirty seconds. i finished the check, got a spare FEL and went up to the catwalk. unplugged the unit pulled the head and inspected the lamp. just a normal blown lamp, slightly warm i just grabbed it and removed it from the socket, set it down on the deck, then turned around to get the spare that i had behind me, BAM!! the old lamp blew as i faced the other direction. the base was the only thing left of the lamp. 

no more warm lamp changes for me.


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## LeChivre

Wow I had something like this happen to me last summer back at USF. I hate FEL's but no where near as much as I hate FLK's. Now those really fail!


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## Edwinlq1go

I have been trying to locate any info (IE: data-sheet, cut-list) for the unit pictured in the above post. I have 8-6x9 units and 8-4.5?x9? units. Any help would be greatly appreciated.


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## llecount

What's the word around here on SPH lamps as a replacement for FEL's? Our supplier recommended them to me for our Lekolite 10x23's.


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## derekleffew

Edwinlq1go, 4 1/2 x 6 1/2, ie., 50° units. Here's the cut sheet for the 1977 Strand Century Lekolite #2321, 6x9, (oops! wrong generation). See Strand Archive - Leko Range in the Strand Archive. 6x9 was SC#2209 and 4.5x6.5 was SC#2204.
http://www.controlbooth.com/forums/members/edwinlq1go.html


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## NevilleLighting

Every once in a while a lamp blows, just does. That is why most PAR's have a screen. Technically every lamp is supposed to have something between it and the stage, even if the something is a clear gel, although I have no idea what a gel is going to do to stop glass shrapnel. Many PAR's predate the screen requirement and I did get to see one blow during an invited dress with about 800 people in the audience. It showered red hot glass down on to an actress. She kept going but we stopped the show to remove the rest of the broken glass.


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## ship

llecount said:


> What's the word around here on SPH lamps as a replacement for FEL's? Our supplier recommended them to me for our Lekolite 10x23's.



Have not tried the SPH 575/115 lamp yet. Got them to play test but have not had time yet. A quick warning went out to me in that lamp's advertising on the other hand: "20% brighter in Par & some" Lekos. That beats the estimate of the now discontinued Osram HPR lamp in being 15-20% brighter in Lekos due to its internal reflector completing the ellipse of the reflector, but on the other hand look at the language Ushio uses. Brighter in PAR and "Some" Lekos. That's a red flag for me before testing in if it says "Some" Lekos... what brand of Leko is it brighter in?


Again have not tried it yet verses the GLC or GLA and what sock I still have in the HPR. This much less verses a GLD and GLE lamp. Could be great but on the other hand in a simple way if you insert a reflector so as to complete that black hole for light inside a reflector assembly I can see a boost in efficiency in the lamp's output. If my lamp specification says on some Lekos it's going to be brighter... my qestion is not as much about how now 20% brighter (fill in the blank as to what in comparison in me not remembering), more simply about that word "Some" as stated in the specification.

While the luminous output of the SPH lamp is 1,000 lumens more than a GLC lammp on paper, I would still ask the vendor to provide both lamps in shoot out with color meter to prove what the assurt given the specifications don't provide this info sufficiently to support their claim. In other words, make the sales person work for his or her profit margin. 

Me, I don't know yet in not having tested such lamps. I do know that the Osram lamp now is supposted to be as good as the Philips GLC lamp in them having done an upgrade to it. GE/Thorn in specification seems low in what's published in output for the lamp.

Beyond all this, and way back on the forum back to HX-600 lamps as compared to FEL lamps, the HX-600 lamp at 575w/115v as compared to a FEL at 1Kw/120v is like a 800w lamp at a higher color temperature as compared to a 1Kw lamp at a lower color temperature.

Same though with better optics with a HPL lamp. Not persay more light and indeed a FEL was a terrible in efficiency lamp, more about that higher color temperature in making it seem brigher than the FEL.

For actual output one more would want to go with a 750w/115v lamp in getting close to output but with more refinened filament so the light produced gets out of the fixture in being brighter plus having that higher color temperature. On the other hand, if one can have less light and be satisfied, that's another fixture per dimmer you can install on it and go with the 575w lamps. Stages are too bright these days most often anyway. The FEL for instance is not designed for a 360Q, while it could be used in say a less efficient fixture so as to pump out enough light.... not for a 360Q and to some extent while it in a 360Q
did pump out a bit more light it also trashed more and more fixtures in doing so.

This heck, I got this 1.2Kw lamp that will function in a 360Q or other fixture for sheer output. Filament ain't very refined but one can use in in being powerful enough granny needs to wear shades when coming to the show.


So the above question of the SPH lamp... Go Ushio if it's better than a GLA in not having to go GLD in wattage, but on the other hand I would play test such a theory given the advertisement. Goal is more output and a higher color temperature and efficiency so as to make it seem more intense yet, but still get say four fixtures per dimmer. That's the goal in not having to exceed more and more in excess. Sure say a 750w lamp persay if competing with moving lights or 1Kw lamps in general but if on stage hopefully the 575w lamp if not the long life version of it is sufficient.

Compared to what often the qestion in "percieved" intensity.


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## TimMiller

whenever a lamp says its brighter 2 flags go off in my head. To actually make a lamp brighter, you produce more heat, or you shift the color temp to make it appear brighter. So which is it?


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## derekleffew

TimMiller said:


> ...To actually make a lamp brighter, you produce more heat, or you shift the color temp to make it appear brighter. So which is it?


OR, (hopefully as in the case of the SPH) the filament geometry more closely resembling the "theoretical point source" makes the fixture more efficient. That being said, I've yet to see a lamp beat an FEL in delivering footcandles to the stage in a Strand Lekolite 2123.


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## ship

TimMiller said:


> whenever a lamp says its brighter 2 flags go off in my head. To actually make a lamp brighter, you produce more heat, or you shift the color temp to make it appear brighter. So which is it?



Balance in general between color temperature and luminous output in being more given voltage but lamp hours being less for the most part in concept in balance. Four things to balance for the most part in lamp design. 

That's in general for lamp design on the other hand. When a lamp is designed for a lighting fixture on the other hand such as the HPL lamp or the new 1Kw AlumiPAR lamps designed for PAR 64 fixtures I was told are TBA to the market really soon, in those cases it's less about the above standards in a filament can only get up to like 3.5K or 3.6K in output before melting thru out of limitation before one considers, yes you have a filament and it has X amount of output as its own limitation before some liquid filled halogen/xenon fluid works with the filament lamp in allowing the filament to operate a higher color temperature and luminous intensity as per projector lamps already using such concepts.

What the HPL lamp and in general grid or stacked filaments allowed in given current limitations of the above voltage, output, colortemperature and lamp life did for the industry was an addition of smaller fillament cubic size needed for what was stable in design otherwise in working. Instead of a linear filament, we get a stacked filament or one on a grid that is designed with high technology so as to prevent arching between filament coils but also small enough in size that you get closer to that "Point source of light" design concept with any Leko ellipsoidal reflector spotlight.

That's the basics in lamp design. Lower the voltage of the lamp to more match that found at the fixture after voltage drop, lower the lamp life some and smaller the size of the filament and you get the HX-600/HPL lamp technology for the most part. More light gets out both by way of smaller cubic area of point source of light and operating voltage of the filament in operating at a closer voltage to what the fixture is seeing in reality.


The HPR lamp while a bad design in going FLK instead of more efficient filament GLC was an interesting design development none the less even if mistake. Such a lamp had a reflector inside of the lamp much like that of the FEL/R lamp that's long discontinued but also had an internal reflector. Such lamps and filaments were what they were but they had a reflector inside the lamp that sort of filled in that hole inside the reflector taken away from the reflector needed to insert the lamp within. It was in adding efficiency without heat if not even removing some lost heat, a more efficient but I'm told very difficult thing to do in adding this simple reflective plate into the lamp.

Still though there is ways to add to lamp efficiency.. Xenon gas goes further in allowing for a higher operating temperature within the lamp. Many halogen lamps already have the xenon gas within it. Some way of doing a liquid filled halogen/xenon filament lamp makes lamp makers sweat in their sleep in instantly asking about who is doint it already I think. Smaller filament cubic areas than next after completing the ellipse. 

Found it fascinating recently an article about tubular lamps like work light T-3 4.11/16" lamps that instead of needing a bunch of filament hangers for them, they found a way to instead pinch the globe of the lamp to support the filament instead to support the filament. There is technology out there and no word on GE's appairent two year old upgrade to the HPL, but all is coming, much less many manufacturers count the days until the pattent on the HPL is gone before they both improve it and improve all lamps.


SPH potentially good. Try it. I don't know.


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## llecount

I've got 7 of them (SPH's) sitting in my office right now. I'm just as curious how they'll perform. 
I can post pictures of the differences between the 2 lamps if I can get them to turn out decently.


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## derekleffew

Please do. We love pictures and shoot-outs. But it might be best to post your results to this thread: http://www.controlbooth.com/forums/lighting/6751-ushio-releases-sph-575watt-115volt-lamp.html.


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## Drueke

*Suggestion for a replacement for FELs*

Hi,
I read this thread yesterday and joined today to get some advice.

I just purchased 2 (very used but in good condition) Strand 2212s that came with FELs. Their application will be front lighting in a music school performance space. The throw is probably about 20-25 ft. They will be mounted in the back corners of the room around 11ft off the floor. They will be gelled w. something like pale amber or pale pink.

500w would probably be enough and I could put them both on the same circuit (different dimmers) however 750w would give me some 'headroom.'

What is the recommendation for a replacement. Longer life is good.
Thanks,
Ray.


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## derekleffew

*Re: Suggestion for a replacement for FELs*

Either of these would be fine.
ANSI Watts Volts Temp Life Lumens Price
*GLA* 575 115 3050 1500 13000 $18.25
*GLE* 750 115 3050 1500 17400 $25.90
Compare with the first generation of this lamp family.
*EHD* 500 120 2950 2000 10450 $17.16
*EHG* 750 120 3000 2000 15000 $15.55


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## gordonmcleod

*Re: Suggestion for a replacement for FELs*

It was at one time recomended that axial lamps be rotated periodically 180 degrees to reduce filament sag
If you want to here a good bang be around a watercooled 15KW xenon when it decides to expire


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## derekleffew

*Re: Suggestion for a replacement for FELs*

Not an FEL, in fact, only a 500W lamp, but of the same family and one of the most interesting lamp failures I've ever seen:



from Jim On Light .

One could speculate about this with many hypotheses.


 Since in a Fresnel, the lamp burns base down, all the heat is concentrated at the end of the envelope.
 Because of the spherical reflector, all the heat is concentrated on one side of the lamp.
 The coiled-coil filament geometry doesn't suit itself well to a spherical reflector. A planar filament, such as on the BTL family, makes much more sense. But using an EHD is not unique to Kliegl; Altman used the same lamp in some of their 6"FS (65Q) for a time.
 What chemical compound would cause the yellow powder on the inside of the envelope? Sulfur?
 What caused a portion of the filament to get sucked outside the envelope?


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## zmb

Consider that the lamp would contain a halogen (Flourine, Chlorine, Bromine, or Iodine), it could be a reaction between one of those with possible skin oils if someone did a bad job changing the lamp or some other foreign item that cause the yellowness to occur.

Indeed, a very strange lamp failure.


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## Grog12

*Re: Suggestion for a replacement for FELs*


derekleffew said:


> [*] What caused a portion of the filament to get sucked outside the envelope?
> [/LIST]


 Since explosive decompression has time and time again been disproved by Mythbusters one can assume that it was explosive compression that blew it out of the lamp as opposed to it being sucked out.


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## derekleffew

*Re: Suggestion for a replacement for FELs*


Grog12 said:


> ...has time and time again been disproved by Mythbusters ...


Speaking of the busting of myths, some may find this video enlightening.

stagelightinc's Channel - YouTube


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## Esoteric

I had one blow out the lenses of an Altman 360Q and rain glass down on two actors looking directly at it during a show.


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## derekleffew

Esoteric said:


> I had one blow out the lenses of an Altman 360Q and rain glass down on two actors looking directly at it during a show.


The same incident as this, 

Esoteric said:


> Well, I had that happen during a show. Only it totally blew the glass out and on to the actors who were having an intimate moment on stage, raining glass down on them. They didn't even flinch.


or are you being redundant, again?


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## Nelson

Wow, that video was interesting! I really think that Mythbusters needs to tackle this one now.


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## josh88

I can just see that. (granted I'd be one of the people who wants to) Hi everybody, today we're going to tackle a myth that 70 percent of our viewers don't care about or don't understand! granted if they could actually make some bulb blow up and break things people would still be interested. It just seems like convincing them to do it would take a little work haha.


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## Esoteric

Hahaha... Didn't see this was a revived thread from 2009.


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## Lambda

I remember when I was first getting involved in tech theater, we had a lamp blow. The LD was up on the genie focusing lights, and he asked me to go to the dimmer rack and bump the one he was working on. After doing so, I looked up just in time to see the thing explode, red-hot glass falling out of the front of the barrel. It gave the LD a pretty big scare. 
The fixture in question is a source four. It was a new lamp, so we assumed that it had been accidentally touched. Until I saw that video, I always thought a touched lamp would explode immediately.


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## techieman33

josh88 said:


> I can just see that. (granted I'd be one of the people who wants to) Hi everybody, today we're going to tackle a myth that 70 percent of our viewers don't care about or don't understand! granted if they could actually make some bulb blow up and break things people would still be interested. It just seems like convincing them to do it would take a little work haha.



you mean more like 99% wouldn't care


Lambda said:


> I remember when I was first getting involved in tech theater, we had a lamp blow. The LD was up on the genie focusing lights, and he asked me to go to the dimmer rack and bump the one he was working on. After doing so, I looked up just in time to see the thing explode, red-hot glass falling out of the front of the barrel. It gave the LD a pretty big scare.
> The fixture in question is a source four. It was a new lamp, so we assumed that it had been accidentally touched. Until I saw that video, I always thought a touched lamp would explode immediately.


 
No, I think it's generally accepted that it shortens the life of the lamp, not that it will make it blow up right away. Who knows maybe it's all a big cover up by lamp manufacturers to cover up their defective lamps


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## Nelson

How does touching a lamp shorten its life? I'm not doubting that it does, I'm just curious how it happens. I always assumed it shortened lamp life by causing them to explode, not burn out faster.


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## JD

*Re: Suggestion for a replacement for FELs*


derekleffew said:


> Not an FEL, in fact, only a 500W lamp, but of the same family and one of the most interesting lamp failures I've ever seen:
> 
> 
> 
> from Jim On Light .
> 
> One could speculate about this with many hypotheses.
> 
> 
> Since in a Fresnel, the lamp burns base down, all the heat is concentrated at the end of the envelope.
> Because of the spherical reflector, all the heat is concentrated on one side of the lamp.
> The coiled-coil filament geometry doesn't suit itself well to a spherical reflector. A planar filament, such as on the BTL family, makes much more sense. But using an EHD is not unique to Kliegl; Altman used the same lamp in some of their 6"FS (65Q) for a time.
> What chemical compound would cause the yellow powder on the inside of the envelope? Sulfur?
> What caused a portion of the filament to get sucked outside the envelope?


 
Just looks like a regular filament sag blister pop to me. With age, the filament which is soft when on, sags due to gravity until it contacts the envelope. Envelope forms a blister where it touches. Sooner or later blister pops and filament squirts out. Saw this many times on VNSP par bulbs. Sometimes would take months before it actually went.

No idea about the yellow stuff, but it looks neat!


----------



## mstaylor

*Re: Suggestion for a replacement for FELs*

It was always my understanding that the oil from your hands would weaken the envelope and thus make it blow sooner. I never tested that theory and may simply be one of myths of lighting. Lamps were always too expensive to test on a short budget.


----------



## FMEng

*Re: Suggestion for a replacement for FELs*

I don't find the video very compelling. It seems to me there are a lot of variables that their tests didn't take into account. Everything from how clean his hands were, the heat dissipation of the particular lighting instrument, to the formulation of the glass, to the type and brand of the lamp. There are just a pile of factors that could affect the chances for catastrophic failure. 

I think most people here would agree it's important to handle bulbs carefully to avoid problems.


----------



## mstaylor

*Re: Suggestion for a replacement for FELs*


FMEng said:


> I don't find the video very compelling. It seems to me there are a lot of variables that their tests didn't take into account. Everything from how clean his hands were, the heat dissipation of the particular lighting instrument, to the formulation of the glass, to the type and brand of the lamp. There are just a pile of factors that could affect the chances for catastrophic failure.
> 
> I think most people here would agree it's important to handle bulbs carefully to avoid problems.


Even the video agrees that it is less than conclusive but he certainly isn't advocating handling lamps barehanded. It may be as simple as he has very little oil/acid in his hands.
I worked in my uncle's musical repair shop. When refinishing brass instruments the final step before laquer was coloring, polishing with jeweler's rouge. Most people, myself included, can't touch a colored piece of brass with causing it to turn. My uncle could handle barehanded with no problem.


----------



## Les

*Re: Suggestion for a replacement for FELs*


mstaylor said:


> It was always my understanding that the oil from your hands would weaken the envelope and thus make it blow sooner. I never tested that theory and may simply be one of myths of lighting. Lamps were always too expensive to test on a short budget.



The oils from your skin supposedly cause the envelope to burn hotter where you touched it. Supposedly.


----------



## Gern

*Re: Suggestion for a replacement for FELs*


Les said:


> The oils from your skin supposedly cause the envelope to burn hotter where you touched it. Supposedly.


 
When I got to Hollywood in the late 1980's, the first Gaffer I worked with told me his rendition of the Tungsten-Halogen cycle. He said the finger oils create a 'cooler' spot on the quartz envelope. The 'cooler' area allows the tungsten to stay on the envelope and over time less and less tungsten makes it back to the filament, finally causing the filament to break. 
Around 2000, I was on a GE commercial for a month in Ohio and met some of the GE engineers who design the studio bulbs we use. I told them what I was told, and they said my version was way simplified, and that there was a lot more to it, but they agreed, it creates a 'cooler' area on the envelope.
Now, after seeing that video with him saying hotter, I did a small net search and everything I see calls it a 'hotter' area on the envelope. Hmm...
Either way, after all these years seeing globes with dark 'fingerprints' where the filament has stuck to the envelope, I 'believe' that human fingers on a halogen globe will, over time cause a globe to prematurely burn out.


----------



## shiben

*Re: Suggestion for a replacement for FELs*

Just a thought, but either way, the failure might be related to expansion of the glass and differences in? How interesting...


----------



## Grog12

*Re: Suggestion for a replacement for FELs*

Having worked in hardware for longer than I care to admit I can tell you that with consumer level halogens you can indeed get catastrophic failure by touching the lamp. I've seen more finger printed lamps come back to try and be returned because the consumer didn't follow directions.


----------



## JD

Ah, but the cooler area causes a hot spot! Once tungsten starts to deposit, light and heat are blocked from exiting the bulb so that area absorbs more and the envelope may fail.

Truth be known, the effect of touching a lamp may be overblown. However, with lamps costing what they do, why chance it. It just seams like good practice. 

I have seen the same types of failures that are often blamed on bulb handling occur in sealed PAR64 lamps. One could postulate that the bulb was somehow handled at the factory, but I am pretty sure that is not the case.

Still, why chance it. Who wants a fingerprint on any of the optics of a fixture? Although the lamp envelope does not effect the focus of the beam, it can help scatter it.


----------



## navy4534

*Exploding 575 HPL*

Had a 575 explode in one of my s4 pars. Ive had this happen before but it has never shot through the Lens. Ideas as to why this happened? We have about 20 of them hanging over our band and i can't have these lens raining down on the band. Was told that the lamp was a Pale Bright Blue right before it happened and was a loud pop then flaming glass...


----------



## DuckJordan

*Re: Exploding 575 HPL*

it happens. if you feel uncomfortable about it put a metal screen in the gel slot. It will help keep large glass bits from coming down until you can maintenance the fixture. Honestly it happens so rarely that we even stopped doing it in our main stage space. Although we do put them in our 2k Fresnels the temperature drop from on for 20 mins to off in our space can cause our lenses to crack the screen helps the cooling curve of our lenses. Or so it seems.


----------



## JD

*Re: Exploding 575 HPL*


navy4534 said:


> Had a 575 explode in one of my s4 pars. Ive had this happen before but it has never shot through the Lens. Ideas as to why this happened? We have about 20 of them hanging over our band and i can't have these lens raining down on the band. Was told that the lamp was a Pale Bright Blue right before it happened and was a loud pop then flaming glass...



Funny how this thread comes back to life whenever there is a violent bulb blowout! 
What happens is the filament sags, shorts, and the shortened section skyrockets in color temperature (and just plain temperature) before melting a section of the lamp envelope and then Ka-Boom! (under a nice high pressure.) 

Most often, the failures are more of a sput-puff.... but when conditions are just right, Boom it is! That's the real thing, out of maybe a thousand failures, you may get two that actually cause something to leave the fixture. (Except for un-screened PAR lamps.)


----------



## derekleffew

*Re: Exploding 575 HPL*

Thread re-named from "Epic fail (why FELs are bad)" to its current.

Agree with the screen concept. A 7.5" x 7.5" piece of 1/2" grid hardware cloth in the inner colorslot would work, but may cause color media to burn faster, even if it doesn't touch the screen.

Note that some sort of screen is required on all open-face (lens-less) fixtures, and I believe in Europe and other parts of the world, on ALL stage/studio luminaires.


navy4534 said:


> ...Was told that the lamp was a Pale Bright Blue right before it happened ...


I believe the technical term, around here at least, is super nova. The filament shorts, intensity and color temperature soars, and the lamp dies a valiant, spectacular death. Ninety-nine point something percent of the time, the envelope stays intact, however.


----------



## derekleffew

*Re: Exploding 575 HPL*

Photo from a friend. HPL575. Heard a loud "pop", then went to investigate and found this.


----------



## crgranner

*Re: Exploding 575 HPL*

I've had this happen a few times before. In old Altman's. It sounds like a shotgun going off. Scares the audience to death when it happens.


----------



## JD

crgranner said:


> *Re: Exploding 575 HPL*
> 
> I've had this happen a few times before. In old Altman's. It sounds like a shotgun going off. Scares the audience to death when it happens.


Oh yes, the good old FEL 1000ACP ... err... I mean Watt. 
Best bass response is achieved in the Altman 1000Q followspot. The "chamber" is just large enough to make it sound a bit like a cannon. Had one go during a quiet, dramatic scene once. Had to wonder if some of the audience seats would need to be steam cleaned afterward.


----------



## Les

Got an interesting lamp failure for ya. I was cleaning up the technical storage area today and thought I'd investigate some NFG complaints of our "Starball" fixture.



Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career.


----------



## GreyWyvern

Les said:


> Got an interesting lamp failure for ya. I was cleaning up the technical storage area today and thought I'd investigate some NFG complaints of our "Starball" fixture.
> View attachment 14405
> 
> 
> Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career.
> View attachment 14406
> 
> View attachment 14408
> 
> View attachment 14407


That is not a failure and is actually the way the lamp is made. The glass is what holds the filament up and in place. Notice that there isn't a wire post or anything else to hold it.


----------



## ship

Dropped a wire rope with cotter pin retainer shackle into my bag one day after an install. Had to use it for a template length for shorter ones with turnbuckles to adjust for ceiling height. Hit the can of Coke on it's side in the bag in just such a way it made a firecracker pop sound. Literally, it was loud and hit in such a way my tool bag wasn't much filled up with exploded soda. Never seen or heard that before. 

Somewhere on this website in the way back when' section - like 10 years ago is a "Killroy was there" proto of a lamp that when it's filament blew out of it, it both left a gunshot like freeze animation in the globe where the filament blew out of the other side. On the opposing side, there was this WWII graffiti like shape to the globe puckered in the shape of Kill Roy on the lamp when the gasses were sucked out.

On the other hand, what you present is "Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career." really interesting in that there is no halogen effect' silver tungsten buildup around the areas of the holes you note. Overall, the globe is clear and shoud not be a reason. There was no escaping silver tungsten elements deposited on the glass indicating that the "halogen effect" has been disturbed.

Initial suspect would be the filament hanger broke and let the filament brake thru the globe if say wiggling. If filament hanger not broken in allowing the filament to wander I would be really interesting. Any other answer short of BB" gun shot thru the cloud thru the lamp, it should have given an indidation as to your hole. Very interesting. One I have not seen before. Glass straw seen perhaps the filament hanger instead?

Perhaps in seeing it before, someone touched the upper hanger part of the inner capsule somehow. It retained heat and (how new is this lamp) did it's job in exploding. Problem is, normally one would see other than a clear lamp in failure. Voltage will blow a lamp - lightning strike blew it out? Doubting this. Perhaps a break somewhere in the capsule in causing a while operating pucker of the globe? This will have also sucked out the silver of the free halogen tungsten filament as to where it were located.

Fascinating given no indication of why it failed how it did I can see. Last chance, perhaps broken filament at the upper support burnt thru the outer globe and once thru it sealed up the hole in the glasss, than wiggled to the other side in crating the hole.

Would require a filament to loose itself from the upper hanger and free float between sides of the outer globe. Burn thru one side of the globe quick enough to pucker it in air coming in, than move to the other side of the globe in burning into it also,, peraps burning a hole thru it before failure. G

Interesting failure, short of seeing it in context I cannot guess further. Hope it helps.

PS. I have seen a lot of T-3 RSC lamps going dimpled outer globe filament support hanger "T" type globe lamps out there. They have dimples in the outer globe to support hangers for the filament.

Is it possible you have a dimple for the upper filament support hanger and some other cause of the failure? Just wondering in not having seen a dimpled upper support before but possible as a concept for science of cooling the lamp.


----------



## microstar

It appears this thread about catastrophic lamp failures has resonated at one high school performing arts center. From a Chauvet LED installation blurb:
"*LAS CRUCES, NM *– Joe Price, the manager of Oñate High School’s Performing Arts Center, knew that the time had come to replace the facility’s incandescent lighting rig with an all-LED system. The 20-year-old incandescent fixtures used at the school’s theater in Las Cruces, NM, were not only inefficient and costly, they also posed a potential hazard. This was made abundantly clear one day when an overhead lamp exploded."
Sounds like one lamp exploding in 20 years resulted in a brand new all-LED lighting system! Good job Joe!


----------



## TNasty

I see a bunch of these pictures, and I can't help but to think that this is why I put a box of blue nitrile gloves in my tool box. Paper towels can be a risk, since oils can sit on them from people grabbing the roll.

Anyways, it's interesting seeing how each bulb dies- some go black, some blue, others rainbow, and some... explode! I've got some rather "vintage" bulbs marked 'dead' in some drawers in my booth- big spherical 500w bulbs. One of them has the most amusing little blister on it (not even an inch in diameter).


----------



## JD

You know, I'm going to to miss all this when the world goes 100% LED. LED's die in the most boring way. 
It's sometimes fun to sort through old boxes of lamps just to see the new and unique ways they all died.


----------



## Les

I'm going to miss the smell from hot dusty lights. These days, I only ever experience it when I'm focusing the front lighting. We traded a few dozen Par 64's for Elation Sixpar 200's a few years ago. 

Not that I miss the par cans - at all. And I really should clean out the dust in the ellipsoidals...


----------



## Jay Ashworth

I lost an overhead halogen once. House light. Fixture was missing the safety.

One piece put a hole in a lady's silk shirt.

Yes, I raised holy hell.


----------



## TheaterEd

I once had a 135w incandescent screw base house light just decide it was done and the glass bulb portion came free from the socket and fell to the floor. It was pretty cool to see, just glad no one was sitting there and it was after most of the audience had left from a concert.


----------



## GreyWyvern

TheaterEd said:


> I once had a 135w incandescent screw base house light just decide it was done and the glass bulb portion came free from the socket and fell to the floor. It was pretty cool to see, just glad no one was sitting there and it was after most of the audience had left from a concert.


I had this happen to me at home a few months ago. I got home from work, and saw a light bulb laying on the floor beneath the living room ceiling fan. On looking closer, I saw that it was just the glass part. I use the GE Reveal at home. A year or two ago, they switched to a halogen version of it to be more energy efficent, fewer watts for the same lumens. The halogen lamp is inside of a regular glass bulb so it looks the same. So, although the outer glass is missing now, it still works fine and I haven't replaced it. I'll try to remember to post a picture. The only thing that bugs me is that it is now a bit brighter than the other three due to the missing outer glass.


----------



## sk8rsdad

GreyWyvern said:


> although the outer glass is missing now, it still works fine



[HIJACK]
The outer glass might be a safety feature. I know some residential halogen lighting fixtures require a glass shield over the halogen lamp to prevent flammable materials from contacting the envelope of the halogen lamp.
[/HIJACK]

My most recent lamp failure led to a $400 repair bill. A Philips MSR Gold 300/2 MiniFastFit decided it was tired of life after 50 hours and went out with a bang, blowing it's top and taking out the glass diffusion on the shutters before coming to rest in the CMY blade assembly.


----------



## venuetech

I think that the outer glass is both a safety feature and a color filter/enhancement on the reveal lamps.
The outer glass is (in theory) to contain a violent failure of the halogen envelope. 

On a side note: I was once told by my lighting professor that the quartz envelope when broken and embedded in a person. Does not show up on x-rays in the same way ordinary glass would. Does anyone have experience or further knowledge?


----------



## GreyWyvern

sk8rsdad said:


> [HIJACK]
> The outer glass might be a safety feature. I know some residential halogen lighting fixtures require a glass shield over the halogen lamp to prevent flammable materials from contacting the envelope of the halogen lamp.
> [/HIJACK]


That would make sense. The lamp is somewhat protected as the is a decorative glass around it and it is 10' in the air. The end is open though.


venuetech said:


> I think that the outer glass is both a safety feature and a color filter/enhancement on the reveal lamps.
> The outer glass is (in theory) to contain a violent failure of the halogen envelope.


The color is a bit different now too. Hmm, didn't think about it containing a violent failure, though I should have. Part of the reason I have just left it as is, is because I've been to lazy to haul the ladder into the house to deal with it! So far, the halogen version seems to fail sooner than the old style, but none have been violent.


----------



## RonHebbard

TheaterEd said:


> I once had a 135w incandescent screw base house light just decide it was done and the glass bulb portion came free from the socket and fell to the floor. It was pretty cool to see, just glad no one was sitting there and it was after most of the audience had left from a concert.


*TLDR Warning firmly in place;*
1968 or 9; Multi-year renovation and expansion of a local hospital. They added a new, much larger, staff cafeteria. Ceiling fixtures were each about 2' square, mirrored glass, approximately 16 clear, candelabra based, globular, ornate 15 or 25 Watt lamps per fixture and about 30 fixtures in the room. Finished ceiling height maybe 10'. When we were about two days away from turning over that wing, the foreman sent two of us in to remove all protective materials, polish all of the mirrored surfaces and lamp all of the fixtures warning us to be sure our hands were clean and not to leave grubby fingerprints all over the place. Roughly 480 lamps. It took a while. 
We were given lots of Windex and clean cloths and the other guys harangued us for grabbing the "white glove" work. Maybe an hour in, my journeyman decided we should power up one of the dimmers and see how things were looking. He noticed we had several lamps 'DOA' and suffering 'infant mortality'. One of the sub-foremen came by and suggested we'd save time by setting all of the dimmers at 25-30% and leave them there so we'd know if we had a 'DOA' lamp the instant we installed it and could save the time of dragging the ladder back. It was pretty slow going, the day was rolling by, things were looking good and we figured we had enough lamps within the 10% mandatory spares to complete the room then have the lamp supplier supply additional lamps to turn over to the client. Got to the end of the day and we were asked to put in an hour of O.T. to reach completion so the cleaning contractor's overnight crew could do a final construction cleanup and the furnishings contractor could load in his snazzy new cafeteria tables and chairs the next morning. 
Got it finished, looked dazzlingly elegant. Journeyman sent me for the sub-foreman. Sub-foreman sent me for the foreman. Much patting of backs and happiness all around. Foreman announced his approval and told us to turn 'em off and call it a day. Someone shut 'em down and within seconds clear glass envelopes rained down on the floor with the majority of them shattering having just fallen 10' to the tile. Many had hit the floor while others were hanging wobbling, hung on the exposed filament structures. Much unhappiness. Much pointing of fingers. It was after dinner hour and getting darker so someone began turning on the remaining lights. 'Nova-ing' of exposed filaments. Several globes that had been hanging were now plummeting. More unhappiness. Even more finger pointing. crap moved slowly up hill. The lamp supplier's rep' was phoned at home mid-dinner. We were finally sent home. First thing next morning, while the furnishings were loading in and making ladder access problematic, various levels of management from owner's rep's to architects, yada, yada, arrived to flog the lamp supplier. The remaining lamps were once again lit, initially at reduced levels, and then raised slowly over a period of time to full under the supplier's rep's direction. Much speculation as to the cause of the problem. The semi-knowledgeable all had an opinion. The most knowledgeable kept their mouths closed. The mystery became why did so many die while others refused to fail no matter how bright or how long? We had to move tables and collect various samples, both of functioning lamps and globe-less candelabra bases. The supplier, Sylvania possibly, needed time to analyze the remnants in their labs and conjure an answer / solution. The immediate problem became what are we to re-lamp the fixtures with in time for the grand soire only days away. The supplier did not have enough stock in the area to re-lamp the room and no one wanted to eat the cost of the re-lamping even if they did. The supplier wanted at least a week. The owners and their fundraisers wanted their show-piece room for their fancy opening for their financial contributors. 
I can't remember the exact details but I believe we lamped every second socket (as it was all they could provide in time) with frosted lamps which the supplier had in stock, and felt could be trusted to not fall in the caviar, then went back to that wing more than a month later to re-lamp the entire room with the specified, clear, lamps. It took longer this time with all of the furnishings in the room and having to do a portion of the room at a time so the doctors and surgeons could eat their meals while we were working. 
Joseph Brant Hospital in Burlington, Ontario with one entire wall glass from floor to ceiling and overlooking Lake Ontario. The hospital's still there. It's been renovated at least twice more over the years and they're expanding again as I type. Unfortunately I've been seeing too much of it lately, these last few times as a patient.
Oh, the lamps!? They deemed it dissimilar rates of expansion / contraction when heating and cooling. Some lamps bases had been formed from brass, or similar, while others had been formed from aluminum. They found both base materials had held up when initially tested but cooled / contracted at different rates. They had the base, the glue and the glass. One material / combination worked as designed / expected while the other combination cut perfect little circular holes in the clear glass globes upon cooling. I believe that particular room disappeared in one of the successive renovations.
I still remember the sounds of those initial lamps hitting the tiles like a hail storm.
With apologies for droning on.
Toodleoo!
Ron Hebbard.


----------



## venuetech

A sales agent once convinced me to buy inexpensive replacement lamps for the houselights.
When it came time to change them the base would remain stuck in the mogul screw socket. Leaving me holding just the glass, with the crumbling glue or whatever falling out as I stood on the ladder under it.


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## firewater88

20170321_125456



__ firewater88
__ Mar 21, 2017



Lamp Failure





Found this one today when changing over for another show. Never heard it and no one told me about it. Swapped out the fixture with a spare until I can clean this one out. Have had issues with a few batch's of USHIO's in recent past.


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## JD

firewater88 said:


> 20170321_125456
> 
> 
> 
> __ firewater88
> __ Mar 21, 2017
> 
> 
> 
> Lamp Failure
> 
> 
> 
> 
> 
> Found this one today when changing over for another show. Never heard it and no one told me about it. Swapped out the fixture with a spare until I can clean this one out. Have had issues with a few batch's of USHIO's in recent past.


Ahh! 
HPL that turned into an HELP
Still waiting for this thread to fetch a nice Xenon failure! Of course, generally they are so traumatic nobody things to take a picture!


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## ship

Most likely a finger %@&! - touched lamp given what I see. Good advice would be to inspect the rest of your fixtures, see if evidence of this problem further from a saff member. Re-Re train your staff on properly installing lamps. No' they didn't do it but re-training on proper installation of a lamp is a easy.


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## ship

HPL lamps might have a little xenon in them but it's not persay a xenon lamp. It is a halogen lamp and the normal cause of such a failure is someone touching the lamp with oily or dirty fingers, or a dirty lamp all of which absorbs heat when on the very pure quartz glass of the lamp. The glass as if a reflector or collector dependant on the circumstance becomes cooler or hotter than the halogen effect cycle in ballooning the lamp globe before it stretches until it bursts. The tungsten electodes of the tungsten halgen filament cycle is attracted or repelled to a lamp globe problem in causing a lamp failure.


----------



## firewater88

ship said:


> Most likely a finger %@&! - touched lamp given what I see. Good advice would be to inspect the rest of your fixtures, see if evidence of this problem further from a saff member. Re-Re train your staff on properly installing lamps. No' they didn't do it but re-training on proper installation of a lamp is a easy.


That shouldn't be to rough to retrain the staff, I'll just have to use a mirror and talk to my self even more than I already do!
Not saying it's not a bare finger touch, but that's unlikely, more likely a dusty lamp or just bad lamps. That one had a date code that was fairly old and probably already had a lot of hours on it.
I have long since switched over to Osram lamps anyway, so I know that one is old. Had a whole box of those USHIO go total black all around the same time in my lobby S4s.


----------



## TNasty

firewater88 said:


> Had a whole box of those USHIO go total black all around the same time in my lobby S4s.


Consistency is key!

We've pretty much only bought from Osram. The only exceptions would be our follow spot FEL's (Impact), mover Halides (Phillips), and Altman strip lights (Something).


----------



## DELO72

Les said:


> Got an interesting lamp failure for ya. I was cleaning up the technical storage area today and thought I'd investigate some NFG complaints of our "Starball" fixture.
> 
> Pulled out the little 100w halogen lamp and was greeted with this. A perfect little dimple on each side, with a glass straw connecting them, with the filament neatly draped over (couldn't blow air through it though - I tried). Seems like there was a mini implosion. One of the more artistic lamp failures I've seen in my career.



Ah yes, the newer "Dimple" Filament design. This has been in place on a variety of smaller-wattage lamps (under 300W usually) for at least 7 years now. It's believed to be more robust than the design with mounts and supports which can break. It's also less expensive to make (I assume) as it has less components and fewer process steps as a result. Definitely NOT the result of an implosion.


----------



## JonCarter

I'm amazed to read of these lamp problems. In something like 25 years of stage & studio work (1955-1980) I've _NEVER _ had any such problems with General Electric, US-made lamps! Of any kind--large lamps (up to 10 kW) or small general purpose lamps. Is everything made nowadays foreign crap???


----------



## techieman33

JonCarter said:


> I'm amazed to read of these lamp problems. In something like 25 years of stage & studio work (1955-1980) I've _NEVER _ had any such problems with General Electric, US-made lamps! Of any kind--large lamps (up to 10 kW) or small general purpose lamps. Is everything made nowadays foreign crap???



Unfortunately GE is no longer making theatrical lamps. Which really sucks, my old strand LEKO's loved GE FEL's. And the Osrams that we use now don't last nearly as long, and depending on which version we get don't even fit in our 2200 series fixtures. The ones with the metal base and rounded corners fit fine. The ones that are all ceramic have sharp corners and won't fit in the sockets.


----------



## RonHebbard

techieman33 said:


> Unfortunately GE is no longer making theatrical lamps. Which really sucks, my old strand LEKO's loved GE FEL's. And the Osrams that we use now don't last nearly as long, and depending on which version we get don't even fit in our 2200 series fixtures. The ones with the metal base and rounded corners fit fine. The ones that are all ceramic have sharp corners and won't fit in the sockets.


When I opened Theatre Aquarius in Hamilton, Ontario, Canada in the fall of 1991, our ellipsoidal inventory consisted of 246 fixtures, mostly of Strand's 2200 series as Source Fours hadn't hit the market yet. I researched lamp brands and everybody I asked said accept only GE FEL's but Ushio's would be acceptable for the 500 Watt and 1 & 2 K fresnels & PAR 64's. Our initial lamp order was 300 GE FEL's, to allow for our first years spares, and Christies supplied everything else as USHIO's. ALL lamps proved to be totally satisfactory with only one USHIO Iris Cyc lamp arriving damaged and immediately replaced. FEL's often cracked the lenses in the Strand 2204's and occasionally in the 2209's but that was Strand's fault for insisting they were rated for the 1K's and not GE's fault at all. Eventually, after Strand had supplied MANY replacement lenses, we agreed to lamp the 2204's down to 750's and that was the end of the cracking lens problems.
Toodleoo!
Ron Hebbard.


----------



## JonCarter

_"Unfortunately GE is no longer making theatrical lamps. Which really sucks, " _
Too bad. Maybe this will be fixed in the future . . . We hope!


----------



## JD

JonCarter said:


> _"Unfortunately GE is no longer making theatrical lamps. Which really sucks, " _
> Too bad. Maybe this will be fixed in the future . . . We hope!


I'm afraid GE is only focused on the mega-dollar products for large commercial and government operations. When it comes to consumer products, they are only a "brand" that gets licensed out to many other companies. This migration started many years ago. For example, all their consumer electronics branding was sold in 1988 to Thomson Consumer Electronics.


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## derekleffew

Ah yes, in the olden days of 750T12/9 being the standard lamp for Lekos, GE was the best; Westinghouse the worst. Sylvania somewhere in the middle. "Foreign" meant Thorn. There were no Asian imports.


----------



## Jeff Lelko

So I had a sealed beam Par 64 lamp blow its lens off last weekend. No broken glass and the lamp tube itself is still intact, but the whole thing ended up in about 6 pieces from the force of the pop (can, lens, lamp reflector, socket, retaining ring, rear of can). It made that wonderful loud 'bang' too... All the necessary safety hardware was in place so nothing fell, but I've never seen one go like that!


----------



## JonCarter

OK, I'll give you another "catastrophic lamp failure." We were working on a picture in a steel mill. This was in the early 60s (_19_60s, that is) and were shooting with Eastmancolor which had an ASA of 25 at that time. Now, steel mills are large buildings, this one being something likle 800' long and 200' wide with a 120' ceiling. And it was dirty. So, a lot of light was required for any long shots. Also, the existing light was a bajillion of some kind of HID fixtures on the roof framing, so it was close to daylight color temp. As we couldn't overpower this, we had to use camera filters which lowered the ASA to 16. We had a four brute arcs, some 150s, and a few inkies, mostly 10s and 5s and a couple deuces for the closeups. The arcs liked DC, so the mill gave us 250VDC by tapping onto crane rails up in the framing somewhere. LARGE bunch of feeders dropping down from the sky to spider boxes on the floor. Being 250V, everything had to be in pairs, connected in series. This worked fine for the arcs as long as the guys coordinated striking. It worked fine for the inkies, too, until somebody got one ten seriesed with 2 fives. (10 kW in series with 10kW, should be fine, right?) When we lit things up, somebody turned on the ten, then went to the fives. Now, had they turned on BOTH 5s first and then the ten, we would have been fine. But the ten was turned on first, then they turned on ONE of the 5s. Ever seen a 5kW lamp go off like a BIG flashbulb?


----------



## RonHebbard

JonCarter said:


> Ever seen a 5kW lamp go off like a BIG flashbulb?


 @JonCarter No and have any of the observers seen ANYTHING since?
ToodleOO!
Ron Hebbard.


----------



## JonCarter

RonHebbard said:


> @JonCarter No and have any of the observers seen ANYTHING since?
> ToodleOO!
> Ron Hebbard.


Oh yes, everybody was looking at the shot, not into the lamps. At least all the glass & other bits & pieces stayed in the instrument. But cleanup was fun!


----------



## Scarrgo

One day in the shop we were setting up some MR-16 4 cir strips for a demo, one of the guys grabbed a rack and plugged them in, as he turned on the breakers the came on super nova bright for about 3 seconds, then went out...so he grabbed another strip, same thing happened, grabbed another strip, same thing, while grabbing the 4th strip someone asked what he was doing, he explained his dilemma, and the guy freaked out on him as he had blown 60+ MR-16 lamps by running 208v thru them.
After asking why he didnt ask for help after the first one went super nova, his response was...."I thought it was odd, must have been something wrong...." was a lovely day...and here's your sign...


----------



## RonHebbard

Scarrgo said:


> One day in the shop we were setting up some MR-16 4 cir strips for a demo, one of the guys grabbed a rack and plugged them in, as he turned on the breakers the came on super nova bright for about 3 seconds, then went out...so he grabbed another strip, same thing happened, grabbed another strip, same thing, while grabbing the 4th strip someone asked what he was doing, he explained his dilemma, and the guy freaked out on him as he had blown 60+ MR-16 lamps by running 208v thru them.
> After asking why he didnt ask for help after the first one went super nova, his response was...."I thought it was odd, must have been something wrong...." was a lovely day...and here's your sign...


 @Scarrgo It's O.K. to run 208 volts THROUGH them so long as you don't leave too many volts parked in any one 6, 12 or 24 volt filament along the way.
Toodleoo!
Ron Hebbard.


----------



## Scarrgo

RonHebbard said:


> @Scarrgo It's O.K. to run 208 volts THROUGH them so long as you don't leave too many volts parked in any one 6, 12 or 24 volt filament along the way.



oh he parked so much that he got a parking and a loitering ticket.....


----------



## ship

Makes me feel better about the PAR 36 pinspot lamps I blew up in series to get line voltage - but miscalculated. Or the dozens of halogen lamps I touched early in my career. Doesn't make me feel better about the employee fired because he did something without proper supervision. And a mistake once educated about would never be made again. Granted three times is a chime, but where was the supervision during all of this?


----------



## Scarrgo

I thought someone was playing with a lighting strike....and I did something like that when the shop sent out the wrong voltage ACL's...I didnt check, just installed, oh look, bright light...for a sec...lol

They didnt fire him, but moved him back to being the truck driver, and there are a couple of funny head smacking storys about his driving also, but different thread....

He was a nice enough guy but he had what we called the "crow syndrome", wanted to do all the fun things, but than would wine because someone else was driving the truck, his truck...


----------



## Les

techieman33 said:


> Unfortunately GE is no longer making theatrical lamps. Which really sucks, my old strand LEKO's loved GE FEL's. And the Osrams that we use now don't last nearly as long, and depending on which version we get don't even fit in our 2200 series fixtures. The ones with the metal base and rounded corners fit fine. The ones that are all ceramic have sharp corners and won't fit in the sockets.



I know you posted this a while back, but I remember a thread about this a few years ago.


DELO72 said:


> *Meekly raises his hand*. Mea culpa. That would be us. Guilty as charged.
> 
> Back in 2007 we had a few production lots where our ceramic supplier mis-read a 3 as an 8 on a spec. in the curvature of the base, and we had a few G9.5 bases that didn't fit into about 10% of the sockets on the market (some older TP220 ones with VERY tight tolerances). It didn't get noticed at first because they still fit in the other 90% out there... We eventually switched later that year over to all aluminum G9.5s to avoid the issue in future runs. We haven't had any problems since.
> 
> Question to the original poster is- Are they Ceramic bases, and if so, are they OSRAM? If the answer is no to either one, then your issue is most likely the socket itself being made on the extremely low end of a tolerance. FLKs and GLAs use the exact same G9.5 base, so it's not the base under normal circumstances.


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## techieman33

Les said:


> I know you posted this a while back, but I remember a thread about this a few years ago.



I remember reading that now, I wonder if we ended up with some old stock from wherever it was that my boss ordered those lamps.


----------



## Amiers

On a job site yesterday at a hotel for Destination PlayStation and I saw this gem. 




I couldn’t help but laugh. Phillips what are you doing....

Btw that’s plastic if anyone was wondering. I doubt they saved any money using what they think was less plastic and spent more money on design and the extruder die to mold that. 

I didn’t turn it on as I couldn’t believe what I saw.


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## Scarrgo

I have one of those, works well, I use it in an outside light....light is pretty even as far as I can tell

Sean...


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## DELO72

On behalf of the lamp Manufacturers, I want to lobby the Controlbooth.com folks to unpin this thread. It depresses me every time I log in and see the Thread title at the top and makes me paranoid there is a new issue. Let it die!


----------



## BillConnerFASTC

LED does seem to be putting an end to exploding "bottles".


----------



## sk8rsdad

BillConnerFASTC said:


> LED does seem to be putting an end to exploding "bottles".


Yup, now it's droop, failing emitters and power supplies, inrush current, erratic dimming, etc. 

So... progress?


----------



## RonHebbard

DELO72 said:


> On behalf of the lamp Manufacturers, I want to lobby the Controlbooth.com folks to unpin this thread. It depresses me every time I log in and see the Thread title at the top and makes me paranoid there is a new issue. Let it die!


 @DELO72 Mark; Granted I'm blind and know less than zilch about computers but you must be viewing Control Booth differently from myself as this thread only comes up for me when someone posts to it. Basically, I hadn't seen this thread for quite some time until you posted and dredged it up again. I view Control Booth via the last version of Google Chrome to support Win XP. 
Toodleoo!
Ron Hebbard.


----------



## Amiers

I think he means cause it’s sticky. Some people don’t hit new posts or visit everyday like we do.


----------



## RonHebbard

Amiers said:


> I think he means cause it’s sticky. Some people don’t hit new posts or visit everyday like we do.


* @Amiers @DELO72* Understood. My point is Mark and I must somehow be viewing Control Booth differently as, speaking for myself, once I've read the thread in question it only appears for me when someone adds a new post to the thread. As far as I can see, there's nothing sticky about. The place I see sticky posts all the time is on the ProSound LAB. To clarify, from my perspective, I understand what Mark's saying, and appreciate his concerns, but on my screen I can't see the 'problem'. I know from nothing about viewing "styles" but I think I view via what you refer to as "CB-XEN"
Toodleoo!
Ron Hebbard.


----------



## Amiers




----------



## RonHebbard

Amiers said:


> View attachment 16150


Thank you @Amiers As I suspected, I've NEVER seen Control Booth this way and I'm pleased to stick with how I view it. 
Toodleoo!
Ron Hebbard.


----------



## DELO72

RonHebbard said:


> * @Amiers @DELO72* Understood. My point is Mark and I must somehow be viewing Control Booth differently as, speaking for myself, once I've read the thread in question it only appears for me when someone adds a new post to the thread. As far as I can see, there's nothing sticky about. The place I see sticky posts all the time is on the ProSound LAB. To clarify, from my perspective, I understand what Mark's saying, and appreciate his concerns, but on my screen I can't see the 'problem'. I know from nothing about viewing "styles" but I think I view via what you refer to as "CB-XEN"
> Toodleoo!
> Ron Hebbard.



Ron,

It's "Pinned" or "Sticky" by the forum Moderators. That is the little thumbtack icon you see on the top right. It signifies that it is a thread that is locked to always stay at the top of the L&E forum. I'm not sure why you are lucky enough not to see it, but it shows up at the top for me each time I log in, even if no one has posted in a while. So... David or Mark-- Help a fellow out and remove the thumbtack please!


----------



## BillConnerFASTC

You only see it if you go to forums. I suspect Ron may do as I do, only click on "New Posts", and never see the "stickies".


----------



## Jay Ashworth

Specifically: you only see it as a stickie *if you go to the Board index for a specific forum*.

If you only use New Posts or Recent Posts (as many Old Hats do), you won't see it unless someone posts to it.


----------



## ship

It's there in the area of the welcome part title section but seemingly isn't used much. Given it's called what it is, I can see how Mark has this concern - our repair department at this point replaces just as many if not more LED bad strips or nodes to lamps at this point, yet its not a light source in general topic (which would be useless.) Certainly know I replace possibly as much bad LED tape as I see specific problems with mover lamps or halogen types I'm ready to go even private about for most lamps at this point. There are trends I see but nothing formed up you, and certainly nothing I would go public with. 

Given the lack of use on the constant topic at the head of the discussions, and its lack of use... might be more useful for a topic if brought up when it gets brought up for individual posts.


----------



## benthecat

Just found this hanging out of one of the cyc light. The lamp melted a hole in the reflector.....


----------



## ship

That was definitely a lamp which was touched by the hand. Must have been a good quality brand of lamp for the filament to last that long.

Expand that one reflecteor melted thru by about 48x. One summer we had 8 cyc's come back with melted down or seriously burnt reflectors. Never seen that before... Only thing I could figure was the person prepping the lights cleaned the reflectors with GoofOff instead of denatured alcohol. Couldn't reproduce the problem other than with this in testing all cleaning materials in the department.


----------



## Rose03

I had a similar thing happen where a FOH par (I didn't put it there) had a lamp blow with such force it took a piece of lens. The scary thing was that the lamp explosion was powerful enough to crack the lens and send a chunk flying down 20 feet into the audience, but when the piece hit the floor it stayed as one. The explosion of the lamp must have been more powerful than the fall back to Earth (scary stuff). Theres also a large dent in the lamp housing from it.


----------



## JVV

Scarrgo said:


> One day in the shop we were setting up some MR-16 4 cir strips for a demo, one of the guys grabbed a rack and plugged them in, as he turned on the breakers the came on super nova bright for about 3 seconds, then went out...so he grabbed another strip, same thing happened, grabbed another strip, same thing, while grabbing the 4th strip someone asked what he was doing, he explained his dilemma, and the guy freaked out on him as he had blown 60+ MR-16 lamps by running 208v thru them.
> After asking why he didnt ask for help after the first one went super nova, his response was...."I thought it was odd, must have been something wrong...." was a lovely day...and here's your sign...



We just got some brand new Birdies and MR16 lamps to go with them. Yesterday I put an edison plug on one and when I plugged it into a regular wall socket the lamp exploded like a gunshot. I thought, bad lamp, so I tried again. Same result. Then I thought I wired the plug wrong, so I tried a new plug. Same result. I thought it might be that unit, so I wired a different one. Same result. So I thought it was my wiring, so I had our LD wire it and same result. Then I thought it was the outlet, so I went to another room and tried it again. Same result. We even brought another lamp from another space to test. Lamp flared, then went out. Any ideas?


----------



## techieman33

JVV said:


> We just got some brand new Birdies and MR16 lamps to go with them. Yesterday I put an edison plug on one and when I plugged it into a regular wall socket the lamp exploded like a gunshot. I thought, bad lamp, so I tried again. Same result. Then I thought I wired the plug wrong, so I tried a new plug. Same result. I thought it might be that unit, so I wired a different one. Same result. So I thought it was my wiring, so I had our LD wire it and same result. Then I thought it was the outlet, so I went to another room and tried it again. Same result. We even brought another lamp from another space to test. Lamp flared, then went out. Any ideas?



Check the voltage on the lamps. Some MR16 lamps are available in different voltages. You may have 12v lamps.


----------



## RonHebbard

techieman33 said:


> Check the voltage on the lamps. Some MR16 lamps are available in different voltages. You may have 12v lamps.


 *@JVV* and *@techieman33* Phrasing that a different way: Comparatively few MR16 lamps are rated for 115 or 120 volt more or less standard North American consumer level line voltage. (From the cobwebs of my mind ANSI EZK 's are one of the few but I'd look that up before quoting me.) I believe the majority of MR16's are rated for voltages typically ranging from approximately 6 volts on up to in the area of 28 or 30 volts; wattages, currents, intensities and anticipated hours all vary as well. Some "birdies" are sold with internal transformers, others with external transformers and some are sold 'raw' with the expectation of the purchaser providing their own transformers and / or other means of ensuring the correct voltage is being provided for the lamps. For a few examples (Note neither suggestions nor recommendations) Possibly you're planning to series connect ten 12 volt lamps and apply 120 volts; similarly maybe you're planning to connect four 28 volt lamps and apply 110 volts. On the other hand; maybe your application is in your travel trailer and you're powering your lamps with 12 volts DC from your batteries or you're powering 28 volts lamps from the system in your private plane. 
*BOTTOM LINE*: _As previously posted_; *ALWAYS* check the voltage ratings of your lamps BEFORE you blow your budget blowing lamps and possibly inflicting pain, suffering, vision loss, yada, yada, etcetera. 
*@DELO72* As a manufacturer, would you care to bring your professional expertise to this post*?* _ PLEASE!_
Toodleoo! 
Ron Hebbard


----------



## Jay Ashworth

You can get 120V MR16's, but I don't think you'll find them in the industrial market much; they're mostly consumer lamps.

You just blew a crap load of 12V lamps.


----------



## Ravenbar

I'm rarely around anymore so this is the first time I recall seeing this post. Reminds me of an experience back in college where the lamp in a 360Q went out as I was about 2 feet away balanced on a railing adjusting said light. I thought I'd saved the lamp as it had a volcano shape sticking out the side, but no idea where it ended up. May have been an FEL as those were commonly used in the 360Q's there.


----------



## ship

Did you dissemble the fixture and examine the components to it? Perhaps plug, cord or fixture there was a short between hot/neutral/ground?


----------



## John Anderson

Although I am now retired, my former company (teamlighting.com) represents Philips/Strand and Leviton (who purchased Colortran a number of years ago). My knowledge of exploding lamps dates back almost fifty years . The lamp manufacturers issue a caution not to touch the lamp with bare hands (bodily oils will cause decomposition of the quartz surface, thereby weakening its structure). Use gloves provided by the lamp manufacturer and if not, provide your own soft work gloves. A failed quartz halogen lamp (often reaching end of life) can perform what the lamp manufacturers term as a “non-passive failure”, meaning it explodes. I have seen Lekos and fresnels destroyed by exploding lamps, so be careful how you handle them.


----------



## Chris Cotter

Spader said:


> Yeah...FELs go out with a bang. At our theatre here, we have an inventory of about 20 S4's and 30 Strand Lekos (Which use FEL lamps). Whenever the Lekos go out, everybody knows it. When the S4's go out, no flash, no sound, no nothing.
> 
> I just remembered:
> I have a PAR64 lamp to replace this weekend because it went out this past weekend. It was really cool when it did go out, because suddenly this bright purple light filled the room.


I had a par 64 go out once and it sounded. Like a shotgun going off !!!


----------



## ship

In a question I don't yet see answer to yet.... how are the new, off brand or fixture maker sold lamps for PAR 64's working out? Lots of suppliers have stepped up in supplying them thru alternate brands or the same? But I have had no word either from where I work shows installing them or other people using them about how well such lamps are doing yet.. 

I know of Keller Williams lamps supplied by TMB and coming from Mexico. And there is no return policy if say lamp code got mixed up and you got the wrong lamps... But lamps are now stocked sufficient for say 30 lamps in a purchase to ship out. A note in not TMB better or less and having sufficient stock, just that stocking lamps has ramped up some seemingly in otherwise a month or two out in the corrected lamp re-bought. Some lamps ordered I am waiting on to be made.

What's the status of the DWE, FCX, #4596, #4552 all standard for the industry also. I don't know.


----------



## DuckJordan

All of my experiences with the new off brands are inconsistent color temp, spreads and of course the amount of DOA lamps is much higher. We've gone so far as to no longer order them at all and switched our overhead stage wash to using more expensive but readily available fresnels.


----------



## EdSavoie

Had a FEL fail spectacularly shortly before christmas right as i was putting gel in, this was in a FOH position, so my face was probably about two feet away.

Colour temperature jumped up for about a second or two, where i'm assuming the FEL turned into an arc lamp, and then blew its guts out of a small hole at the bottom of the envelope. I unfortunately didn't think of getting a photo of the otherwise surprisingly intact lamp.

Everyone in the house heard it go off, I was promptly asked if I needed to change my pants (I did not need to)


----------



## RonHebbard

EdSavoie said:


> Had a FEL fail spectacularly shortly before christmas right as i was putting gel in, this was in a FOH position, so my face was probably about two feet away.
> 
> Colour temperature jumped up for about a second or two, where i'm assuming the FEL turned into an arc lamp, and then blew its guts out of a small hole at the bottom of the envelope. I unfortunately didn't think of getting a photo of the otherwise surprisingly intact lamp.
> 
> Everyone in the house heard it go off, I was promptly asked if I needed to change my pants (I did not need to)


* @EdSavoie* Nary a need to change your pants if the FEL's blown them clear in time. Please don't ask how I know this. 
Toodleoo! 
Ron Hebbard


----------



## BillConnerFASTC

All these reasons to convert to LED.....


----------



## techieman33

BillConnerFASTC said:


> All these reasons to convert to LED.....



Sure, that's ideal in a lot of instances. Sometimes you just want a good old fashioned par rig though. Another problem is that a lot of venues don't have the money to make the swap. Buying a couple cases of par lamps can be a challenge. Coming up with $20k+ to buy LED fixtures, lenses, cables, and some way to power them could be nearly impossible.


----------



## ship

DuckJordan said:


> All of my experiences with the new off brands are inconsistent color temp, spreads and of course the amount of DOA lamps is much higher. We've gone so far as to no longer order them at all and switched our overhead stage wash to using more expensive but readily available fresnels.



Interesting the Fresnel option for going. None the less, not proper to bad mouth a supplier or it's brand in general info short of other's citing problems in general with PAR's so far so please don't respond with that info at this point. Thanks for in general confirming my caution to be concerned about. I have not heard back from the tour using a few hundred of the lamps yet in if a problem. I will contact/remind them so as to track such lamps in performance. Something of interest to study overall.


----------



## RonHebbard

techieman33 said:


> Sure, that's ideal in a lot of instances. Sometimes you just want a good old fashioned par rig though. Another problem is that a lot of venues don't have the money to make the swap. Buying a couple cases of par lamps can be a challenge. Coming up with $20k+ to buy LED fixtures, lenses, cables, and some way to power them could be nearly impossible.


 *@techieman33 * All the items you've listed AND distribute control data to and fro' them as well; the data cables are only parts of the data distribution system: Splitters, terminators and nodes, et al, dependent upon your system's complexity and needs. 
Toodleoo! 
Ron Hebbard


----------



## JimP0771

Is it possible that the Bulb did that? I touched a bulb putting one in to a fixture one time years ago when I was young before I knew you could not touch them and that bulb needless to say did not last long and it went out with in just moments of heating up?


----------



## DuckJordan

ship said:


> Interesting the Fresnel option for going. None the less, not proper to bad mouth a supplier or it's brand in general info short of other's citing problems in general with PAR's so far so please don't respond with that info at this point. Thanks for in general confirming my caution to be concerned about. I have not heard back from the tour using a few hundred of the lamps yet in if a problem. I will contact/remind them so as to track such lamps in performance. Something of interest to study overall.


I prefer not to name and shame vendors unless its clear we didn't get just a bad couple batches. As far as switching to fresnels its a band-aid until next fiscal year to replace with ETC D40's and we have 80 6" Fresnel in stock


----------



## JD

So, I was using an old Altman PAR64 lamp for a work light yesterday. Nothing unusual, just hanging there when after about 15 minutes, BANG! Glass sprinkling everywhere... I figured it might have had a burner tube rupture that shattered the outer envelope but I was wrong. Once things cooled down I took a look. The explosion was forceful enough to push the socket and part of the base out of the adjustment hole in the back of the can but to my suprise, the quartz tube was intact! (see picture.) I suspect the filament rupture was simply from the shock of the outer glass exploding. The lamp was certinally not new, but not really old judging by the fact that the filament windings were smooth (as compared to the crusty look from many halogen cycles.) There was no stress on the lamp, just the usual retaining ring. The lamp had lived in the fixture a long time and seemed happy there until now. The only unusual thing is that it was a Thorn-Emi lamp. I have never purchased any Thorn PAR lamps! All of my stock has always been GE or Sylvania. The only thing I can figure is that it may have been replaced when out on a rental, which would have been years ago. As to why it exploded, I have no idea!


----------



## RonHebbard

JD said:


> So, I was using an old Altman PAR64 lamp for a work light yesterday. Nothing unusual, just hanging there when after about 15 minutes, BANG! Glass sprinkling everywhere... I figured it might have had a burner tube rupture that shattered the outer envelope but I was wrong. Once things cooled down I took a look. The explosion was forceful enough to push the socket and part of the base out of the adjustment hole in the back of the can but to my suprise, the quartz tube was intact! (see picture.) I suspect the filament rupture was simply from the shock of the outer glass exploding. The lamp was certinally not new, but not really old judging by the fact that the filament windings were smooth (as compared to the crusty look from many halogen cycles.) There was no stress on the lamp, just the usual retaining ring. The lamp had lived in the fixture a long time and seemed happy there until now. The only unusual thing is that it was a Thorn-Emi lamp. I have never purchased any Thorn PAR lamps! All of my stock has always been GE or Sylvania. The only thing I can figure is that it may have been replaced when out on a rental, which would have been years ago. As to why it exploded, I have no idea!View attachment 20798


*@DELO72* Can you offer a plausible explanation? 
Toodleoo! 
Ron Hebbard


----------



## ship

Wow! That's an interesting failure I have never seen before as described. 

Lamp ceramic looks a bit old and discolored perhaps by way age or from rapid gas escape. Either could do similar. Not familiar with any single ended capsule halogen capsules inside a PAR 64 lamp. This is a really odd concept for me... why? Lamp engineers spent many years in the 60's in developing a single ended halogen lamp. Later the 120v halogen PAR 64 lamp concept as upsised from PAR 56. This PAR 64 lamp operates best with a dual ended capsule lamp capsule from the early 70's, in spinning the bottle.

Capsule is not innocent - do I see failed "Getter" in smoke ring above it, even if not itself blackened? What's a Getter doing in a PAR 64 lamp? What's with a single ended PAR 64 lamp capsule in a lot of work to make it single ended, - perhaps a "Base Up to Horizon" type problem created failure problem?

This is an alien failed lamp you should save as best possible for Mark from Osram. Put on hold a year or two for .... time and funding to be free'd up so this lamp example can be sent back to the engineers. Not like this question is a rush - more a curiosity.

I have a note about a Thorn GFF lamp existing. One would think Ansi code lamps would be on-line. FFP is troubling but if the basic standards of FFP, it would qualify. Single ended... why?
GFF Thorn (disc.) PAR 64, Quartz 67x68° ?1 Kw PAR64


----------



## DELO72

The lamps are filled with nitrogen (inert gas that helps prevent oxidization (can't oxidize if there's no O2!) of the moly foil in the pinch seals of the inner capsule), So if it was under pressure, heated up, and the seal of the lens to the reflector wasn't perfect, they could easily shatter and separate under pressure. With large PAR lamps more than any other Halogen lamp type, it really IS rocket science to get them to seal properly without stress in the quartz. And I know this because a colleague of mine was an aerospace Engineer prior to working in quality (years ago) at the Sylvania Large PAR factory in Kentucky. In his words, "It does take a rocket scientist- I ought to know. I am one."


----------



## DELO72

ship said:


> Not familiar with any single ended capsule halogen capsules inside a PAR 64 lamp. This is a really odd concept for me... why? Lamp engineers spent many years in the 60's in developing a single ended halogen lamp. Later the 120v halogen PAR 64 lamp concept as upsised from PAR 56. This PAR 64 lamp operates best with a dual ended capsule lamp capsule from the early 70's, in spinning the bottle.



It's basically acting like a Double-ended lamp. They took a CC8 SE lamp and turned it on its side-- Voila! a double-ended CC6 lamp!  It's cheating... but it's clever.


----------



## EdSavoie

BillConnerFASTC said:


> All these reasons to convert to LED.....




I don't suppose you've heard the sound of an NTC operating MOSFET going kablewey?


----------



## ship

I have no idea of what the above message is saying - curious to learn. 

"I don't suppose you've heard the sound of an NTC operating MOSFET going kablewey?" 

Was just helping my child with homework tonight, similar subject of I don't understand this, and the point of the education was, if you don't understand ask help. No shame in that. I'm asking.


----------



## RonHebbard

ship said:


> I have no idea of what the above message is saying - curious to learn.
> 
> "I don't suppose you've heard the sound of an NTC operating MOSFET going kablewey?"
> 
> Was just helping my child with homework tonight, similar subject of I don't understand this, and the point of the education was, if you don't understand ask help. No shame in that. I'm asking.


I suspect kable wey = Ka Boom in Shipese. 
Toodleo! 
Ron Hebbard


----------



## TheaterEd

ship said:


> I have no idea of what the above message is saying - curious to learn.
> 
> "I don't suppose you've heard the sound of an NTC operating MOSFET going kablewey?"
> 
> Was just helping my child with homework tonight, similar subject of I don't understand this, and the point of the education was, if you don't understand ask help. No shame in that. I'm asking.



Kablooie?


----------



## EdSavoie

NTC = Negative Temperature Coefficient
This means it will heat up as current passes through it, but it will draw more current as it heats up. most MOSFETs (a high efficiency transistor used for switching type power supplies) operate as NTC.

This means that if the cooling system fails / the components feeding the MOSFET alllow too much current to pass, it can very quickly hit a critical point where it draws more power when it gets hot, and it keeps getting hotter so it draws more power.

Once it hits the _runaway_ point, it will very quickly spiral out of control, blowing with anything between a quaint little "pop" or a rather frightening "BANG" depending on the transistor, current and luck.

The closest analogue to this behavior I can think of is how an arc lamp can die violently if you don't have something to limit the current. unlike an incandescent lamp which essentially starts as a dead short and then draws less power as it heats up and it's resistance increases.


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## TimMc

EdSavoie said:


> NTC = Negative Temperature Coefficient
> This means it will heat up as current passes through it, but it will draw more current as it heats up. most MOSFETs (a high efficiency transistor used for switching type power supplies) operate as NTC.
> 
> This means that if the cooling system fails / the components feeding the MOSFET alllow too much current to pass, it can very quickly hit a critical point where it draws more power when it gets hot, and it keeps getting hotter so it draws more power.
> 
> Once it hits the _runaway_ point, it will very quickly spiral out of control, blowing with anything between a quaint little "pop" or a rather frightening "BANG" depending on the transistor, current and luck.
> 
> The closest analogue to this behavior I can think of is how an arc lamp can die violently if you don't have something to limit the current. unlike an incandescent lamp which essentially starts as a dead short and then draws less power as it heats up and it's resistance increases.



Thermal runaway.... why didn't ya just say so?


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