Film-Tech Forum ARCHIVE: Kelmar Automation Question

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Posted by Kara J. McVay (Member # 1285) on 04-16-2006, 10:33 PM:

Got a call at closing Saturday night with employee saying that the projector would not shut off. So over the phone we went through the usual suspects. After determining that it was not shutting off, I got in the car and went over.

Long story short, I think I know the answer but I know very little about electronics. Even with cutting the power to the automation, first the power switch on the automation, and then the power source, the projector motor kept running, the only way to get it to stop was to throw the old knife switch on the back wall, labeled "MAIN SCREEN" Keep in mind we just had our 90th birthday.

My question would be: was this caused by a "switch" that got stuck open? The only thing I could think of to do was to open the front of the automation and without seeing anything jump right out at me "wrong", I used a can of air to blow off any potential contact problems. This worked, we threw the switch back on and the motor was stopped and the automation worked again, meaning it shut off when we dropped the failsafe.

I am just confused, because with my lack of knowledge in this area, if it was the automation should it not have shut off when I killed the power to it specifically, without having to shut the entire theatre down?????

Perplexed in Ohio

Kara

Posted by Steve Guttag (Member # 268) on 04-16-2006, 11:20 PM:

You got lucky on that one...merely blowing air into the automation should do very little.

Your two likely culprits are the manual motor switch and the "Power" relay. My first vote would be for the Power relay (often "K1" in Kelmar automations). This relay has both the Motor and the lamp circuits going through it. When the motor starts and stops, it will arc these relay contacts and it is possible that it is bridging on the relay contacts for the motor. To see if this is the culprit remove the relay and see if the motor stops.

If it is the motor manual switch, then it must be replaced. Note there will be lethal voltage on this switch even if the automation is turned off. If this is a modern Kelmar automation, this is very likely the problem as well. Kelmar uses a very poor switch in their current automations that really isn't rated for the load of most projector motors (it is something on the order of 8A which is okay when the motor is running but insufficient for when the motor starts). Better switches can be had, even cheap that will approximately double the rating of the switch.

However, you must first determine what is causing the problem before proceeding to a solution.

Do you not have a local service company to call to take care of such things?

Steve

Posted by Kara J. McVay (Member # 1285) on 04-17-2006, 08:41 AM:

Thanks for the info, I do have a tech I can call. I watch when new equipment or something is being repaired and ask questions, so I can try to have some clue about my equipment other than just knowing how to thread.

Maybe the air worked becasue it is our haunted booth [Eek!]

We have had many "strange" thing happen in this booth. It is the original 1916 booth.

Kara

Posted by Eric Robinson (Member # 2966) on 04-17-2006, 03:24 PM:

Thanks for the tip...next time I get a service call request, I'll save some time by just telling them that their booth is haunted. [Big Grin]

Posted by Mark Gulbrandsen (Member # 72) on 04-17-2006, 08:22 PM:

There are at least three theatres out in the mountain states that I know to be haunted [Eek!]

.

Mark

Posted by Kara J. McVay (Member # 1285) on 04-17-2006, 09:06 PM:

We have had some really strange stuff happen in that booth. I had the fire shutter, which is still attached to the shutter and opens when the shutter spins, shut in the middle of a show, the shutter had never stopped spinning [uhoh]

.

By the look of the other thread, "dumb things managers say" you could get away with just saying it's haunted [Big Grin]