This is topic Deviation in rectifier output current in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Marin Zorica (Member # 1716) on 04-16-2007, 03:17 PM:
I have XBO2500 running @85A, but problem is that sometimes when I start lamp current goes up to 100A, then durring show falls to about 85A!
Problem is that when i start lamp current goes up to 90A and after 20 minutes it falls to 70A......and problem is because rectifier have 6 step regulation...so during show I can't regulate current...
Lamp is new and is same with other lamp.....maybe problem is in rectifier when transformer and diodes get's warmed!!
I'm thinking about replacing diodes with stronger and put better cooling to system, opinion?
Rectifier is three-phase built by one tech company 25-30 year ago.
Posted by Louis Bornwasser (Member # 3063) on 04-16-2007, 03:24 PM:
Is this with all bulbs? I think this is a factor with bulb heating up the gas and pressure building. Have seen this on almost all systems; amps drop after heating. Louis
Posted by Mark Gulbrandsen (Member # 72) on 04-16-2007, 05:51 PM:
On Christie/Ushio lamps this phenomon is so neglagable as to be non existant, a few amps drift at best. Have seen it alot on both Osram and LTI. To be safe and not sorry... also check all the large DC connections and the AC connections to the rectifier, especially those that are crimped. Check all bulb connections as well.
Mark
Posted by Monte L Fullmer (Member # 2797) on 04-16-2007, 06:40 PM:
(like the olden days of carbon arc - the new rods would send the ampmeter up about 10 to 20 amps higher until the positive rod began to develop the crater, then settle down for the duration of the rod..)
Posted by System Notices (Member # 2357) on 06-07-2010, 03:18 PM:
It has been 1147 days since the last post.