Film-Tech Forum ARCHIVE: Lamp keeps switching off in ORC Lamphouse

This is topic Lamp keeps switching off in ORC Lamphouse in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Joe Redifer (Member # 3) on 06-03-2003, 02:38 AM:

I have an ORC lamphouse (brown & beige version)where the 2000 watt lamp shuts off after ten minutes, almost like clockwork. It's not the feather switch for the blower and it's not the door switch. Even with all the panels removed the rectifier stays cool, but the lamp shuts off. New bulb, by the way... and it did it on old bulbs, too. Once the bulb shuts itself off, it cannot be struck again for a few minutes. Once I hear a light "click" sound from the rectifier (where the capacitors are) the lamp can be struck again. I don't see a relay over there. Sounds kinda like a capacitor problem but I don't know what is making the click when it is OK again.

Any ideas on solutions?

Posted by Adam Martin (Member # 641) on 06-03-2003, 04:13 AM:

Are there temperature sensors on the heat sinks in the rectifier? If so, try replacing or bypassing them to see if a faulty sensor is your problem.

Posted by Fabrice Dubourg (Member # 1635) on 06-03-2003, 04:55 AM:

Excessive heat on the positive heatsink normally open a thermal switch and cut power from k1 coil to allow unit to cool before restarting.
is there a problem with the rectifier cooling fan ?

Posted by Ken Layton (Member # 133) on 06-03-2003, 09:35 AM:

Some ORC's have a keyswitch in the snout of the lamphouse that causes problems. Either the switch goes bad, gets out of adjustment, or the connector pins to it go bad (they spread apart under heat) This switch is in series with the air vane switch if I rember correctly.

Posted by Tim Reed (Member # 137) on 06-03-2003, 11:39 AM:

The time factor sure makes it sound like a thermal switch is at fault. Not that I had to reiterate what Adam and Fabrice already said, but I just want to increase my post count.

[Big Grin]

Posted by Joe Redifer (Member # 3) on 06-03-2003, 03:09 PM:

Yup. That was it. Thanks. [Smile]

Posted by Tim Reed (Member # 137) on 06-03-2003, 07:46 PM:

You're sure welcome, Joe! Hey, btw, a print of my intermission clock is going to the Cinderella Twin in Denver. You'll have to stop by and see your name on the screen!

Posted by Adam Martin (Member # 641) on 06-03-2003, 10:22 PM:

Joe's name is Cinderella?

Posted by Joe Redifer (Member # 3) on 06-03-2003, 11:01 PM:

Wo! That's not far from where I live. You serious?

Posted by Tim Reed (Member # 137) on 06-04-2003, 12:34 AM:

Yeah, I told you I'd give you a screen credit for helping with the demo transfer last year.

Posted by Philippe Laude (Member # 79) on 06-04-2003, 03:30 AM:

Another effort Tim, you're almost at 1000!

Posted by Tim Reed (Member # 137) on 06-04-2003, 10:19 AM:

Philippe, I'm sure trying! [Big Grin]

Posted by Scott Norwood (Member # 30) on 06-04-2003, 12:39 PM:

I see that Herb got a screen credit too! [Cool]

(now back to your regularly scheduled on-topic posts)

Posted by Tim Reed (Member # 137) on 06-04-2003, 05:43 PM:

Oh, you're right, Scott. Did I mention the real problem is that it's an ORC?

Posted by Sam Hunter (Member # 1119) on 06-04-2003, 09:43 PM:

quote:
Did I mention the real problem is that it's an ORC?

That hurt, I like my ORC [Frown]

Posted by Tim Reed (Member # 137) on 06-05-2003, 12:33 AM:

Give it some time, Sam. Give it some time.
[Smile]

Actually, the one you have isn't bad for the application, and it's sure convenient enough. I would have one at home. It's just that they were never very efficient lamphouses. And there were a few design flaws that you had to wonder what they were thinking; like the RF coil being located in the front of the lamphouse on the early 6000 model - where all the heat is focused (or was the whole igniter down there, don't remember?).

Posted by Travis Hubrig (Member # 1745) on 06-05-2003, 05:12 PM:

We used to have a 1000w ORC, it was kind of cool...
so little and portable... We kept it for a back up for the XHN lamphouses that we have, We found that the XHN were so reliable that we didn't need the ORC.

Posted by Steve Kraus (Member # 476) on 06-05-2003, 06:38 PM:

Ya gotta admit: Optical Radiation Corporation is/was a cool name. Well, so is ORCON.