Film-Tech Forum ARCHIVE: random shutdown of a christie lamphouse

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Posted by Jonathan Haglund (Member # 807) on 06-13-2001, 01:23 AM:

This is odd. A Chirstie 2k lamphouse I've got just random stopped working today. The bulb won't lite, the exhast fan is pulling air in, and the ceiling exhaust is also going the worng direction. No one touched the damn thing except to thread it. The projector still moves in the right direction. I don't know much of anything about electrical things, so if anyone can help, please be simple in explainations.

Thanks
Jonathan

Posted by Tom Kroening (Member # 201) on 06-13-2001, 02:47 AM:

Have you checked the fuses? Check all the failsafes (for the blower and the doors). Swap out the bulb to see if you have a bad bulb.

Posted by Paul G. Thompson (Member # 655) on 06-13-2001, 02:49 AM:

Check your air flow interlocks. Especially the one in the stack (if equipped). They may be sticking. Blower squirrel cages may need cleaning, too.

Posted by Darryl Spicer (Member # 711) on 06-13-2001, 03:27 AM:

you say ceiling exhaust is blowing the wrong way. Is the motor turning the wrong way or do you feel air coming in thru the exhaust port. You may have a bad exhaust fan on the roof causing the airflow switch to open interlock preventing lamp from striking.

Posted by Brad Miller (Member # 2) on 06-13-2001, 04:19 AM:

Jonathan,

The interlock switch in that lamphouse is above the xenon bulb right below where the exhaust stack is. There should be a tiny little "fan" that can move up and down, which is connected to a little microswitch. Moving the fan up or down a little bit should produce a tiny "click". If your airflow is going in the wrong direction and is sucking air into the lamphouse, instead of blowing air out of the lamphouse, you MUST fix that first. Regardless, it definitely sounds like that switch is just thrown the wrong direction. You could tape it in the "up" position temporarily just long enough to strike the lamp to verify that is what is wrong, but again you shouldn't operate the bulb for a feature before you fix the exhaust issue.

Hope that is explained simple enough.

Posted by Jason Burroughs (Member # 68) on 06-13-2001, 09:46 AM:

first check the little vane in the opening of the stack in the lamphouse, they love to come off.

Does your lamphouse have the auxilary fan on top to draw the air out, or just a roof mounted exhaust fan? Check operation of both fans. If air is comming down, it sounds like the exhaust fan is not working and the negative air pressure in the booth is drawing outside air in. Check your breakers make sure that they are on, you may need to get up on the roof and find the exhaust fan in question and make sure it is running, if it is running, turn it off remove the cover and check the belt, they sometimes break.

Posted by Jonathan Haglund (Member # 807) on 06-13-2001, 12:49 PM:

I will check the interlock today. The weird part about this is the impeller motor is pulling air in, and the ceiling exhaust, which I just installed 2 days ago is now pulling air into the lamphouse. That's why I thought it was something electrical.

Posted by Barry Hans (Member # 477) on 06-13-2001, 01:22 PM:

Johnathan,
Check the wiring on the exhaust fan. I think you have an exhaust motor wired wrong. Check if you can switch the rotation thru the wiring.

Posted by Randy Stankey (Member # 64) on 06-13-2001, 09:19 PM:

I agree with all of the above. The way to confirm this is that the green "READY" light on the console has gone out.

There are four interlocks on a Christie console:

Exhaust stack proof paddle.
Front door switch.
Rear soor switch.
There is a "hidden" proof paddle under the lamp blower. It's in the duct that blows down on the lamp.

All four of these switches need to be closed (engaged) for the lamp to strike. (I believe they are all in series with the contactor coil.)

The door interlocks are pretty academic. Use your "Fonzie Power". Gently bang on the door to make sure the switches are fully engaged. Sometimes they don't close all the way... especially if you only have one of the door latches locked. (I don't know WHY people insist on doing this!)

I've been in theatres when I got called over to a house when the lamp doesn't strike. I just walked over and gave it a quick thump on the door. The lamp fired right up!
They asked me how the hell I did that. I just told them, "I'm the FONZ!"

As for the proof paddles... Well, check the fans, of course! (Ok, I'm being a wise ass again...)

Sometimes the paddles come loose from their little "swivels". You can just snap them back on. Likewise if something else in the switch is busted. It's just a screwdriver job.

OH... The exhaust stack is blowing IN?!!!
Like the other guys... Is it wired correctly?
Also, is there any kind of damper in the duct? If it's stuck shut that could cause strange things to happen. Further, if the blower is not running and it's stuck open the breeze could be blowing down the stack from outside. Sorry to say it but somebody is going to have to go up on the roof and check.

Posted by Jason Burroughs (Member # 68) on 06-18-2001, 01:42 PM:

Just wondering what the final fix for this problem was

Posted by Jonathan Haglund (Member # 807) on 06-19-2001, 12:28 PM:

Not sure why the bulb fan started going the other direction, though it seems it was moving the wrong way to begin with. But the final fix was a bad diode. Me not being a real tech and all didn't think to check this.

-Jonathan