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Topic: Irem rectifier problem

Trevor Bailey
Expert Film Handler

Posts: 113
From: Woonsocket, RI
Registered: Jun 99

posted 11-02-2001 10:50 PM

Hey all,

Well, I had a good one today and perhaps someone else has run across this before.

Irem G3-X75 p.s. in a Xetron XCND console w/ P35GP projector.

Bad strobe on screen...normally a missing phase or open diode.

I immediately saw a terminal burned off the line side of the contactor. I cut the wire back to a good section and rewired with a new contactor. Problem still present. Checked the line side and load side of the contactor...118V to ground and 206V across phases. Diode? Checked all diodes...ok. Well, sometimes a diode will fail under load but test ok...so I replaced all six with six new diodes. Problem still present. Changed the bulb (you never know). Problem still present. No load voltage is about 98V and load is about 23V. I can easily bring the amps up to 82A. All of the tranformer outputs to the bridge test close in volts and amps. I tested and tightened all connections on the p.s. and up to the lamp. The large capacitor measures about 95V with no load and takes several minutes to discharge. I also checked the projector because I was running out of ideas...it appears to be running at the correct speed and the shutter is not damaged and is properly timed.

I would have changed the diodes again but I only have two more spares.

I am getting a little stumped. I called Neumade and they suggested the things I had already tried. I would have called Big Sky but it was too late.

I would greatly appeciate any suggestions. Thanks!

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Rick Long
Jedi Master Film Handler

Posts: 759
From: Toronto, Ontario, Canada
Registered: Nov 1999

posted 11-02-2001 11:14 PM

Well I gotta agree, your first sentence is right, this is a good one.

You tried everything I would have tried.

Just wondering about the burnt wire on the line side of the contactor. How come? I know Irem is not famous for over-tight connections, but just wondering why that phase, is it possible something else down the path drew an unusually high current?

Have you tried checking the continutity of the transformer windings, (pain in the ass, I know, but that is the only thing that comes to mind, other than a burned connection underneath the input lug, which I'm sure you would have checked.

Good luck, and please let us know what it was.

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Rick Long
Jedi Master Film Handler

Posts: 759
From: Toronto, Ontario, Canada
Registered: Nov 1999

posted 11-05-2001 09:32 PM

I know you are already aware of this, but have you checked the veracity of the incoming line?

With the contactor engaged, you may be getting a "back-feed" through the transformer windings giving you a false indication of voltage where there actually is none.

In other words, have you tried checking incoming voltage on the input side of the unenergized contactor?

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Darryl Spicer
Film God

Posts: 3250
From: Lexington, KY, USA
Registered: Dec 2000

posted 11-05-2001 11:56 PM

Yes check that incoming power source...could be a bad breaker for 3phase in the breaker box on the wall.....

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System Notices
Forum Watchdog / Soup Nazi

Posts: 215

Registered: Apr 2004

posted 11-22-2010 04:16 AM

It has been 3303 days since the last post.

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Dominic Espinosa
Phenomenal Film Handler

Posts: 1172
From: California, U.S.A.
Registered: Jan 2004

posted 11-22-2010 04:16 AM

Hi guys,

I'm having a problem with this same model rectifier.

On this one, after a show had run fine the projecionist reported no lamp strike on the next show (second of the day).

I'm reading, at most, a no-load of 60vdc. Without attempting to strike with mode in manual (auto doesn't even trip at this point) the voltage then drops very fast. In 20 seconds or less it's below normal output range of 22-32vdc.

Have checked caps and diods and all 3 incoming legs measure 210 and quite smooth.

Thoughts?

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Giorgio Volpi
Film Handler

Posts: 51
From: Caracas - Venezuela
Registered: Mar 2002

posted 11-23-2010 12:12 PM

Hi,
you can write to Ing. Giaccone at IREM: sva@irem.it
He surely can help you with this problem.
Regards,
Giorgio.

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Richard May
Phenomenal Film Handler

Posts: 1057
From: Floral Park, NY USA
Registered: Aug 2004

posted 11-23-2010 02:20 PM

I had the same problem with the same rectifier. 60 volts. The only difference if the voltage didn't drop. Try changing the starting cap.

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Dominic Espinosa
Phenomenal Film Handler

Posts: 1172
From: California, U.S.A.
Registered: Jan 2004

posted 12-01-2010 06:23 PM

Thanks guys.

It ended up being the magnetic shunt. Only had one leg making contact. It was in pretty bad shape altogether. A wonder it hadn't failed sooner!

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