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Author Topic: Overcooling a Xenon bulb in a Barco? Jay Glaus Expert Film Handler Posts: 123 From: Pittsburgh, PA USA Registered: Dec 2010 posted 03-24-2014 06:17 PM                        That's one of my two guesses. Because I've checked my 3 phase and nothing is out of wack. So, I'm wondering if either something weird is happening cooling the bulb (even though I've checked everything and nothing is blocked or stuck up), or its my lamphouse. The first time I believed it was just a bad bulb, but you can only hold on to that dream so long.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-25-2014 09:56 AM                     You can swap the lamphouses between the 23B and 32B all you want...they physically are interchangeable on the outside. The differences are in the reflectors and lamp mounting hardware (the 23B uses the "SM" version which takes the same lamps as the "C" version projectors). We have some Dolby 3D theatres that use the SM lamphouse for their 2D lamp and the XL lamphouse for their 3D lamp...so I can say with complete confidence...it works just fine. The lamp information is actually stored on the lamp info module on the lamphouse itself. So when that lamphouse is put into the "other" projector...all of the information, including the lamp type and power range comes with it. However, the projector knows its own power range so if you put a 6KW lamp in your 23B projector, you still will top out at 4KW. It won't over drive and destroy the power supplies.  |  IP: Logged Jay Glaus Expert Film Handler Posts: 123 From: Pittsburgh, PA USA Registered: Dec 2010 posted 03-25-2014 01:45 PM                        I'm debating on trying a lamphouse swap and seeing if that makes the new bulb burn right this time. I'll probably wait till Barco gets back to me since I sent them the logs and see if they see anything else wrong. But I have a feeling it's something in that lamp house.  |  IP: Logged Jay Glaus Expert Film Handler Posts: 123 From: Pittsburgh, PA USA Registered: Dec 2010 posted 03-25-2014 04:10 PM                        Barco got back to me. Everything looks good on the logs, their only suggestion was instead of starting it out at 5800 watts, to run it at max it's whole life. Since the new bulb only has 12 hours on it so far, I guess it's worth a shot. Hopefully this will help, I don't know how quickly it will dim, but I guess I'll find out!  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-27-2014 12:40 AM                     What I usually do on a 6500 lamp: use the standard mode and move the slider all the way up to 255. Bulbs just seem to work better at full power than starting out below 80% then gradually ramping up when age gets on them when in CLO mode. I wonder on that CLO mode if that's the greatest thing next to baked bread.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-27-2014 08:43 AM                     See now...my experience with running lamps at max is that it decreases their light output RAPIDLY. I can't claim to have done extensive studies on the 6500s but every other lamp size I've tracked has had the same results...once they get to full power...they just start to decay fast.  |  IP: Logged Joris Springer Film Handler Posts: 83 From: Almere, Flevoland, The Netherlands Registered: Feb 2007 posted 03-28-2014 05:14 PM                     I have to say I am very interested in this topic. At the cinema where I work we have a similar problem with our 4K 32B's. Also with 6500 watt bulbs but from Osram. Last year we had two lamp explosions in two booths (one happened during show, the other during removing of the lamp) and we got two replacement lamp houses (different from the Original ones in the projector but according to the labelling from Barco still meant for the 32B) and that is when the problems started. The bulbs either change color on the forward metal part (not in the lamp itself but the part that keeps the lamp centered, where the wire is attached to, sorry I cant come up with the proper English word, is it the annode?) after even just 30 minutes you could see that part turning blue. When the lamps reach around the 300 hours they start to flicker, first mildly but at some point it is getting worse and we just have to replace the lamp. Also the lamps start to fail to ignite at some moment. We have checked for the valve in the lamp house for the cooling of the lamp from the bottom of the lamp house but there is a clear grid, so nothing blocking the air. The projectors are up to date and since all our 32B projectors have that situation (3 of them and we swapped the lamphouse to the projector with the Original lamp house and that projector also got that problem). In one of the projectors you can even see the foot-lambert steadily decline in front of your eyes on the screen of Barco Communicator. From the support of our digital integrator we heard that the 23b's lamphouse can not fit in the 32, they have tried so that can be crossed of the list. It seems as if the problem is not lamp manufacture specific since the ts is mentioning Ushio. The lamps are not running at their maximum capacity. I dont know a solution to this situation, the ticket is open at Barco and they are investigating it but perhaps it can give everyone some extra information.  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 03-28-2014 06:16 PM                     The main difference between a 23B and 32B is the lamphouse - and lamp power supply count. The lamphouses should be interchangeable but I haven't tried. yet. Steve says he's swapped them and he's a reliable witness, I think. I am a bit leery of your integrator's assertion they can't be interchanged.  |  IP: Logged Joris Springer Film Handler Posts: 83 From: Almere, Flevoland, The Netherlands Registered: Feb 2007 posted 03-28-2014 06:25 PM                     But if the insides of the lamphouse are different doesn't that mean that it can cause problems? Since the lamphouses of the 23B are not build for that kind of heat from the 6500 watt lamps. Sure they might fit into the projector but aren't there more details to think about? Besides, switching lamphouses between 2D and 3D shows from what I understand about Steve's post is not an option since we have the problem even when we only play 3D shows in that booth with the 32B lamp house.  |  IP: Logged Jack Ondracek Film God Posts: 2348 From: Port Orchard, WA, USA Registered: Oct 2002 posted 03-28-2014 08:35 PM                        My 32B has been a constant problem. No 6.5kW bulb has gone beyond 175 hours without striking problems. When I pull the bulb, the divot in the anode is above-center and it looks like the top has been sanded a bit... almost like the flame went over the edge. I'm told a fix for the ignition problem was installed during my last service. That's nice, if that's all it is. Just looks like maybe the anode is drooping on me. You couldn't rotate the bulb if you wanted to... the wire isn't long enough.  |  IP: Logged Jay Glaus Expert Film Handler Posts: 123 From: Pittsburgh, PA USA Registered: Dec 2010 posted 03-29-2014 02:09 AM                        Hi Jack, I recently got that update as well. Here's what I've found... It does help with the striking. I don't know what exactly it changed, maybe it gives the igniter more juice, but it definitely helps with that. I don't know how similar your problem is to mine (it sounds very), but from what i've found, you no longer have any striking problems, but once you get to half life, the brightness really starts dropping off quick and you begin to get an unstable arc. Then you get to the point where you finally pull it and see that she's burning high. Since it's not burning correctly on the anode, the arc wanders and you seem to lose brightness, cause the bulb isn't operating at it's "full potential", for lack of a better term. However, thanks to the update, it still strikes as good as the day you put her in! I've often thought if they would make the cable longer, maybe rotating the bulb would help. I believe the cables screw into the bulb the same way they did back in film. I've been tempted to put a longer cable on from one of my old film bulbs and see if rotating helps, but I figure it's short for a reason. Who knows, maybe you'll have better luck with that than I did/am. Obviously we aren't the only people experiencing this. I'm going to try running mine full and I'm going to pull it at half life. If it looks like it's burning evenly (and hasn't lost too much light from being run at max), I'll be happy. If it still looks like it's burning high on the anode, then I haven't solved the problem. If it's the latter, then maybe I'll do a lamphouse swap with one of my 23's and see if the problem follows the lamphouse. Who knows, I guess time will tell! Jay  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 03-29-2014 02:46 AM                     A pair of pliers can remove that anode cable from the end of the bulb seal with no problem - same thread design, but bet if you do try a longer cable, put a knot in the cable to take up the slack. Yet, I can have one 32B with no strike issues, has about 150 on the strike count, close to warranty pull hours and no flickering on a 65BA2 bulb. Yet, the appearance of the anode is like above, which looks like the anode did take a slight drop to be misaligned with the cathode..along with the three "ripple horns" on the anode tip The other 32B is my problem: occasional failed strikes when reaching its last 100 hrs of warranty run. Thus, to remedy the situation, is to manual strike the bulb a few minutes before the scheduler kicks in per each showing. On a side question about the 23B: I also have two of these units, both are operating with no problems and running DXL-40BAF/L lamps. Thing that worries me a bit is that long, 8 inch brass cathode adapter one must use on the end of the bulb. You remove the bulb from the module and always worry a bit that the weight of that brass cathode adapter is too heavy for the anode end of the bulb, esp when pulling the bulb out and putting the bulb in the module and you can't support that weight in any way or form. Thus, I do my best to get that end pin in the middle of the castled nut more quicker than normal so to get the weight off of the bulb. You think that, if only 4K is the highest wattage of bulb used in a 23B, that the module size could have been reduced to rid of that long brass cathode adapter and go to the standard short one used in the lower units-from a 12C to a 20C, or the ultra short one that the 32B uses. -Monte  |  IP: Logged Jay Glaus Expert Film Handler Posts: 123 From: Pittsburgh, PA USA Registered: Dec 2010 posted 03-29-2014 02:55 AM                        Yeah that is a good point Monte. You'd think they would have done something about that. If you were new to it and didn't know what to expect I could even see wacking the reflector on the way out  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 03-29-2014 03:10 AM                     To be clear. The exterior of the "SM" version of the lamphouse is IDENTICAL to the "XL" version of the lamphouse. They are absolutely interchangable. What I did NOT say is that one could put a 6.5KW lamp in the SM version of the lamphouse. You can't. What is different is the reflector and optics. The SM version of the lamphouse is designed to work with the shorter arcs of the "BAF" series of Ushio lamps. It is not designed to work with the larger arcs of the BA series. Monte, I can definitely share your concern about the weight of the lamp adapter but the thickness of the quartz is such that there really isn't any danger of it not being able to support that amount of weight over the length of the lamp. However, it definitely goes against one's sensibilities. As for Osrams and explosions...well duh! If you use Osrams, you should expect them...those lamps are pure garbage (not just the 6.5KW ones either).  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 03-29-2014 10:13 AM                     Joris, If the Anode end turns blue, you are overheating it. Any damage caused by a overheated lamp will not be manufacturer's liability. 23B lamphouses are called "S/M" (Small/Medium?). 32B can fit both S/M and XL. S/M can fit 1,2kW up to 3kW lamps. XL from 3kW up to 6.5kW. The 3kW lamp for the S/M is not the same lamp for the XL. If you have a 6.5kW lamp in a S/M lamphouse, that's your problem. If you have an XL lamphouse, I would check the extraction, with an anemometer. You are going to bang overheated lamps sooner or later, I would get rid of the problem before you end up paying lots of money for that.  |  IP: Logged

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