This is topic Odd problem with ORC 1000 L/H in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Dave Macaulay (Member # 813) on 05-03-2007, 06:19 PM:
I tried out an ORC1000 for a customer who isn't critical about light quality, just needs something small and 120VAC. The thing checked out fine in the shop. On delivery I get a call that it's "flashing", a deep regular flicker visible on the ammeter and on screen. So I checked out another one and sent it. Then a call that the second is doing the same thing.
So I went and saw it myself. The lamp strikes and immediately starts a deep regular flicker visible in the ammeter and on screen at about 3 flickers a second.
Back at the shop the lamp is steady again.
The facility where it flickers has a whole-building UPS where the incoming 600V 3 phase power goes into a big cabinet full of batteries and electronics, then comes out to the various equipment icluding the 600V to 208V 3 phase transformer feeding the projector. The system does AC - DC- AC conversion full time, dropping to batteries on power failure without any interruption.
My only guess is that the UPS power waveform is a bit bumpy and that the ORC power supply dislikes it.
Has anyone seen any problem like this?
Posted by Gordon McLeod (Member # 33) on 05-03-2007, 07:20 PM:
The ORC is a SCR device and being a switched wave form it probably has issues with the non true sinosoidal waveforms and iffy zero crossing points of the mains that it sees
Probably a set of AC caps on the input might help it along
Posted by Mark Gulbrandsen (Member # 72) on 05-03-2007, 07:23 PM:
Have only seen this when the electrolytics on the driver PCB(top one) go bad. Since the regulator is phase controled it may be hitting a harmonic of the incomming AC. Although those types of large UPS's are pretty dam clean I would take a look at the incomming AC with a scope and see how clean it looks. Careful use of a differential input amplifier on the scope will immediately show up anything annoying on the line, be sure to use an isolation transformer as well!!
Mark
Posted by Gordon McLeod (Member # 33) on 05-04-2007, 07:24 AM:
Since it doesn't do it in the shop I would suspect it is not the unit
Posted by System Notices (Member # 2357) on 06-15-2008, 10:01 PM:
It has been 408 days since the last post.
Posted by Bill Duelly (Member # 3612) on 06-15-2008, 10:01 PM:
I have been searching the old messages to see if there is a problem similar to mine and this seems real close:
My ORC 1000 has a sight flicker to it, irregardless of power source. I 1st thought it was due to a running the lamphouse off of a generator during a summer show, but a similar lamphouse was on the same circuit and was rock steady (the ampmeter does bounce within an amp or two when this happens). I've also tried 3 different bulbs and all had some sort of flicker.
I am not clear if a resolution was found to this problem. Board replacement? Just a component or 2 to replace? Please advise and MANY Thanks!
Posted by Mark Gulbrandsen (Member # 72) on 06-16-2008, 10:14 PM:
Replacing the electrolytic caps on the control board and SCR board usually clears this problem up. You must use the same value caps but higher voltage rating on them is perfectly acceptable as long as they fit in place physically.
Mark
Posted by Bill Duelly (Member # 3612) on 06-17-2008, 06:15 AM:
Thanks Mark! I'll give it a try.