|
|
This topic comprises 2 pages: 1 2
|
|
Author
|
Topic: ORC Rectifier only putting out 40Amps
|
John Walsh
Film God
Posts: 2490
From: Connecticut, USA, Earth, Milky Way
Registered: Oct 1999
|
posted 07-30-2005 06:51 PM
Hi, Frank! When the lamp when out/ relit, did you hear the contactor in the IREM drop out/ pull in?
Or, did the lamp sort of just go out and then relit?
I agree very much with Louis: check the terminals ("A, B, C, D", 3 phase, etc.) and tighten if needed. Also, you can often see the yellow-colored spade lugs on the contactor discolor.
| IP: Logged
|
|
Frank Angel
Film God
Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999
|
posted 07-31-2005 12:35 AM
quote: Mark Gulbrandsen
sounds to me like you should consider calling James Bond at Full Aperature Suystems in Chicago the next time you try to pull off a show..... I think your equipment is beyond ready to be retired.
Mark, I am surprised at you. Where's your sence of the thrill of the hunt? These problems are most fascinating and they certainly up the anti when you are running a film for 4000 plus people and the lamp goes out for a second.....even for that fraction of a second, your brain has already asked, "will it come back? will it blow up? It's better than going on a thrill ride at Great Adventure.
Besides, a rectifier is a pretty basic design -- transformer, diodes, relays, caps. It's not like there are too many things that can go wrong. Short of the transformer winding shorting, any of that other stuff could be replaced fairly cheaply and you;ve got a unit that's as good as new.
The guys opened up both units today to have a look-see and the down unit looks like all the damage occurred at the relay with the all of the wires on the transformer side quite charred and toasty. No damage to the big trany windings that can be seen. There is a molex type blade connector (4 or 5 lugs that it connects to on the circuit board under the relay) that was completely disconnected. I'll take pictures. Not quite sure how that came disconnected (vibration), but the electrican said it was disconnected when he opened the unit. I can't imagine that had anything to do with the failure -- who would design a piece of electrical equipment where if a cable gets vibrated loose, the unit blows up?
So Xetron and IREM are one and the same? They sure look like the same units inside and out.
Welp, it's been a fun weekend....but I am glad I get Sunday off.
| IP: Logged
|
|
|
|
Tim Reed
Better Projection Pays
Posts: 5246
From: Northampton, PA
Registered: Sep 1999
|
posted 07-31-2005 12:52 AM
quote:
the lamp will extinguish for a fraction of a second and then re-ignite immediately. ...low and behold, it happened again last night, twice but on both lamphouses
You may be getting down drafts in the exhaust duct that are momentarily interrupting the direction of airflow, and causing the switches to flop open. I'm not clear, but it sounds like you are running two lamphouses from one rectifier(?), if so, then one of those lamphouses is controlling the safety interlock circuit of the rectifier, and that air switch might be bad. You said you oiled the switch? That is not a fix. When Microswitches/Cherry switches/etc. go bad, there is little of anything you can do to make them last longer. The contact points deteriorate and/or the toggle mechanism fails. You have to replace them with new, or short past them until you can get new.
In fact, just for grins, why not go ahead and replace (or temporarily short past) the airflow switches and see if the problem goes away. And check the outside exhaust system to make sure you're not getting downdrafts.
| IP: Logged
|
|
Frank Angel
Film God
Posts: 5305
From: Brooklyn NY USA
Registered: Dec 1999
|
posted 07-31-2005 07:38 AM
Thanks for the pics, John. We using Craig ProGold contact cleaner on all those connections --ProGold not only cleans but also improves electrical conductivity.
As for the relay in the rectifier popping in and out when this occurs, I can't answer that because I am up on the top floor of the booth and the rectifiers are down at ground level. I can't hear them, although that is not the case with the lighting and sound guys who say they hear the two of them humming very loudly. The lighting/electrician did say he hard a noise from the rectifier at the same time that he heard the lamphouse restrike, which is what I would expect as the lamphouse itself is pretty much ruled out as the culprit.
And yes, Monte, each lamphouse normally has its own rectifier. It just now that we lost the one, I am running both projectors from the one. And when I say running both lamphouses off the one good unit, I don't mean both at the same time. I mean, I got them to put pigtail tees off the good rectifier's DC output and at the change-over, I have the an assistant kill the rectifier, switch the DC pigtails from one lamphouse to the other (actually we just switch the plus pigtail -- we leave both minuses connected) and when the pigtails are properly switch, they fire up the rectifier again and strike the second lamphouse. It just makes the reel changes go that much quicker -- down to about 15 - 20 seconds instead of running on one projector and rethreading each time on the single machine. I mean, I am fast, but not THAT fast.
Tim, I thought the vain switch was the culprit because I had had trouble with it before. But now that I am running BOTH lamphouses on the one rectifier, the problem still ocurrs, it rules out any of the lamphouse safety switches.
Now that we've opened and cleaned all the contacts, we'll see if the problem is fixed.
It also crossed my mind that the relay in this unit may be old and may not have the same pull as the other unit. If there is a momentary drop in the voltage, it may cause the weak relay to momentarily drop out and then pull back. Whereas the second rectifier relay may be holding stronger. The only thing that nixes this theory is that during that glitch, I never see any of the other lights in the booth (we have string lights all tied to this PD box and everything is fed from the same street transformer. You would think a dip big enough to cause a relay to drop out would be big enough to be visible in the existing lighting.
Last bit of info -- these units are laying on their sides. They have been that way from day one, which is five years ago without any malidies, until now. Vents are all kept clear, but we are running in very high ambient temp and humidity -- the week the one went ablaze the temps were in the 90s and equally high humidity.
| IP: Logged
|
|
|
|
|
|
|
|
|
|
|
|
|
|
All times are Central (GMT -6:00)
|
This topic comprises 2 pages: 1 2
|
Powered by Infopop Corporation
UBB.classicTM
6.3.1.2
The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion
and agrees to release the authors from any and all liability.
|
Home
![[Smile]](smile.gif)
![[Big Grin]](biggrin.gif)
![[Cool]](cool.gif)
Printer-friendly view of this topic