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Topic: First Legitimate Breakdown...

Monte L Fullmer
Film God

Posts: 8367
From: Nampa, Idaho, USA
Registered: Nov 2004

posted 04-27-2014 10:37 PM

When I was working with NEC 1200C units and Real D usage, on the display unit on the side of the projector, I did notice 4K bulbs running at 105% when using 3D and would reduce down to 90% for regular usage.

That worried me some for a bulb to be "overclocked" just to push out more light past its maximum. Granted no explosions occured since I did the required pulls (and this was using Philips 4200 bulbs), thus everything went normally.

Now, with working with BARCOS, the big 65BA2 bulbs are never pushed past 100% even in 3D, even though they are pushed close to the maximum when in that mode..in CLO mode. Just when the hours gets close to warranty, I do suffer ignition failures and manual strikes are required.

And when the pull happens and bulb inspection is done, the anode electrode is horribly pitted and "ripple horns" are present on the electrode along with a half darkened envelope.

I think what really kills bulbs is the high 'strike count' that occurs during the bulb's warranty life.

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Jack Ondracek
Film God

Posts: 2348
From: Port Orchard, WA, USA
Registered: Oct 2002

posted 04-28-2014 12:03 AM

quote: Monte L Fullmer
Now, with working with BARCOS, the big 65BA2 bulbs are never pushed past 100% even in 3D, even though they are pushed close to the maximum when in that mode..in CLO mode. Just when the hours gets close to warranty, I do suffer ignition failures and manual strikes are required.

And when the pull happens and bulb inspection is done, the anode electrode is horribly pitted and "ripple horns" are present on the electrode along with a half darkened envelope.

I think what really kills bulbs is the high 'strike count' that occurs during the bulb's warranty life.

I'm having this problem now. So far, none of my 6.5kW bulbs has reached more than 50% hours. The last one I pulled looked pretty bad & was flickering noticeably.

Strikes don't appear to be the problem. I run one double feature per night and the bulb stays on from start to finish. Airflow is about double Barco's spec.

I've been running Ushios at this point. Not ready to try something else, but it would be nice to know what's going on.

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Antti Nayha
Master Film Handler

Posts: 268
From: Helsinki, Finland
Registered: Oct 2008

posted 04-28-2014 09:45 AM

quote: Monte L Fullmer
When I was working with NEC 1200C units and Real D usage, on the display unit on the side of the projector, I did notice 4K bulbs running at 105% when using 3D and would reduce down to 90% for regular usage.

quote: Monte L Fullmer
working with BARCOS, the big 65BA2 bulbs are never pushed past 100% even in 3D

I'm wondering whether those are just different definitions of "100%".

I've noticed that at least Ushio's documents (6.4 MB PDF linked) list much more conservative minimum/maximum operating currents compared to Barco's lamp files. For example, according to Ushio, DXL-30BAF/L's operating power range is 1960-2800 watts, but Barco lets you drive it at 1800-3000 W. So in a sense, 3000 W could be said to be "107% power". I don't know how NEC calculates the percentage.

After encountering some Barco ignition issues, I'm thinking of relying less on CLO in the future and just setting lamp power manually instead in order to keep the wattage within Ushio's limits, and seeing if that helps.

Jack: in case you missed it, here's some earlier discussion about Barco strike failures.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 04-28-2014 11:27 AM

It seems to me there may be a couple of lamps whose specs allow running at slightly high power levels but I'd have to research that to be sure. Selecting the wrong lamp will for sure allow that to occur as will a software glitch. The warranty hours for the DXL-20SN3 lamp has been wrong from day 1 in the NEC firmware. They say it's 3000 hours when it's actually 2400. It's not that big a deal for me because I manually set the lamp warning to 2350 hours for most customers anyway.

Jack: I have two D.I. customers running the Ushio 6KW in NEC's and they have been fine. One customer just started his third season with the same lamp, another is on his second season. You may want to consider stepping down to a 6KW and see if the life span improves any.

Mark

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12814
From: Annapolis, MD
Registered: Dec 1999

posted 04-29-2014 05:33 AM

quote: Jack Ondracek
Strikes don't appear to be the problem. I run one double feature per night and the bulb stays on from start to finish. Airflow is about double Barco's spec.

We have one customer, currently, using the DXL-65BA and they always make warranty. Their exhaust is on the order of 800cfm. My suggestion if you are having an ugly lamp come out is to increase your exhaust up to 800+ cfm. That is a lot of heat to get out of there.

That said, we have people running the DXL-60BA2/L that are also making warranty without issue (in fact, warranty +) though the lamp is darkening, their exhaust is a bit low, in my opinion...we put in an in-line booster (the good ole Fantech) to get it up to where it is...if un restricted (is is pushing into a 6" system since that is what existed before DCinema and they only ran 3KW before...6KW is just for 3D here. The 3KW 2K lamp in this theatre also always makes warranty and comes out looking clean. I think Barco really under specs its exhaust requirements in trying to make their system seem cheaper to install.

quote: Antti Nayha
For example, according to Ushio, DXL-30BAF/L's operating power range is 1960-2800 watts, but Barco lets you drive it at 1800-3000 W. So in a sense, 3000 W could be said to be "107% power". I don't know how NEC calculates the percentage.

It almost seems a mystery on how Barco comes up with their lamp files. I believe there is some trial and error and back and forth with the manufactures. Their system can limit a lamp by voltage, current or wattage such that no parameters can be exceeded. If you look at the DXL-30BA file, you'll see that it has the same 120A max. current but is limited to 2400-watts! Doing the same current/amp math, it should be limited to just over 3000 watts! I know I've seen lamps in Barcos where it can never achieve its maximum current. This is a big change from our film days where current was THE driving factor.

quote: Mark Gulbrandsen
Selecting the wrong lamp will for sure allow that to occur as will a software glitch. The warranty hours for the DXL-20SN3 lamp has been wrong from day 1 in the NEC firmware.

Mark...though I may be the only one doing this...if you user the Certification Code that comes with each lamp...the NEC will select the proper information. Since the NEC puts up red tail lights when the lamp hits warranty or the warning, I tend to also set things to minimize it from "over complaining."

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Sam D. Chavez
Film God

Posts: 2153
From: Martinez, CA USA
Registered: Aug 2003

posted 04-29-2014 09:58 AM

quote: Steve Guttag
I think Barco really under specs its exhaust requirements in trying to make their system seem cheaper to install.

Barco early on did state their projectors were self exhausting and indeed with no ducting it would but made me very nervous. Don't know if relative pricing was the motivation though, just engineering conceit. I had one of their big guys defend the low CFM they spec'd saying it was possible to over cool the bulb. Maybe in theory.

Later on one high tech venue the building engineer would read the manual and not listen to me. Lots of very black bulbs resulted.

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Mark Gulbrandsen
Resident Trollmaster

Posts: 16657
From: Music City
Registered: Jun 99

posted 04-29-2014 10:10 AM

Sometimes I do use the certified number Steve but I have quite a few customers that like a bit more warning as to when the lamp is going to expire. I even have a couple that like a 100 hour warning.

On projector exhaust... Even the Barco 10S and the NC-900 that exhaust into the room will heat up a smaller booth in no time flat. I always have the customer keep the present exhaust system in place and have them run it when the room gets uncomfortably warm. I just remove all the ducting so it is pulling out air at ceiling height.

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