Film-Tech Forum ARCHIVE: TA-10 burning up Kelmar CO dousers

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Posted by Paul G. Thompson (Member # 655) on 09-26-2001, 08:05 PM:

Is it possible for a TA-10 to lock up in the middle of a cycle and fry a douser? So far, one fried in one city, (it was a Zipper) and one brand new TA-10 automation fried a Kelmar.

My documentation is so skimpy that I can't determine squat! I have no roadmap on that system. Just a book that says "Punch the button" to make it go.

Has anyone else fried CO dousers with the TA-10? If so, what caused it?

Paul

Posted by Aaron Sisemore (Member # 145) on 09-26-2001, 10:01 PM:

I have seen countless smoked dowsers with CFS autos and Christie AM5's, but never with any of our TA10s. If the relay isn't sticking, you must have a computer logic problem somewhere in the TA10.

Aaron

Posted by Paul G. Thompson (Member # 655) on 09-26-2001, 10:08 PM:

I have to believe it might be a computer logic problem, as it was doing some flakey things Sunday night last run. But what makes this so tricky to figure is that the person who was running the projectors only knows four things:

1. Location of the start button.
2. Location of focus knob.
3. Location of the frame knob.
4. Location of the break room.

But it is getting better.....

Posted by Rick Long (Member # 213) on 09-26-2001, 11:15 PM:

As Aaron sez, this is unusual with a TA-10 (we have about a hundred of them in service in this area). Any chance of a sticking manual button?

BTW did it fry the open or close side of the coil?

Retro-thinking, we did lose 2 coils, (both on the close side and both Kelmar), but no apparent cause. In both cases, replaced the coils - no further problems).

Posted by Sean McKinnon (Member # 612) on 09-27-2001, 12:30 AM:

Ive seen it happen on a "ZIPPER" with a TA-10. (I still think the TA-10 is an excellent automation though.

------------------
--Sean McKinnon
Manager
Loews Cineplex Entertainment
Liberty Tree Mall 20
Danvers, Mass
www.enjoytheshow.com

Posted by Randy Stankey (Member # 64) on 09-27-2001, 12:48 AM:

Messed up or improperly installed feed wires to the C/O? Neutrals and Hots mixed up, for example?

Messed up or improperly installed manual open/shut switch? It's in paralell with the relay contacts, right?

Programming diodes installed right?

Any of these spitballs stick?

Posted by Paul G. Thompson (Member # 655) on 09-27-2001, 01:12 AM:

It worked fine all through the runs - until the last one, apparently.....Not much to go on, though. I hate these type of troubles you have to second guess. But when you have popcorn salespeople pushing the button, anything can be expected.

The open coil is what fried.

Paul

Posted by Brad Miller (Member # 2) on 09-27-2001, 03:24 AM:

Now's the perfect time to add an inline fuse to the douser. That way if the automation hiccups again and doesn't release, you will only be out the cost of a fuse and anyone can change it.

Posted by John Pytlak (Member # 331) on 09-27-2001, 08:30 AM:

Paul said: "the person who was running the projectors only knows four things:

1. Location of the start button.
2. Location of focus knob.
3. Location of the frame knob.
4. Location of the break room."

Hey, at least they know where the focus and framing knobs are! Hopefully, they spend more time checking presentation quality than they do in the break room.

(And Brad and Joe will remind us that a good projectionist shouldn't even need a framing knob )

------------------
John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services, Entertainment Imaging
Research Labs, Building 69, Room 7525A
Rochester, New York, 14650-1922 USA
Tel: 716-477-5325 Cell: 716-781-4036 Fax: 716-722-7243
E-Mail: john.pytlak@kodak.com
Web site: http://www.kodak.com/go/motion

Posted by Bill Purdy (Member # 202) on 09-27-2001, 12:53 PM:

I have waited to respond to this until I could consult with our Technical Service guy, Don Olson, because he is the one who interfaces with the real world. He reports that he has never seen this as a result of program error, but in a couple of cases, and only with Zippers, there have been welded together relay contacts. In other systems he has seen Kelmar's dousers fry to the point of smelling pretty bad, but still not burn out. This seems to be in agreement with other posts above.

The douser relays in the TA-10 normally get a 300 millisecond pulse and this is a software thing. (Note to Randy: the lower power relays are all controlled by the processor, not the Event strapping.) We have had those rare cases of one of the relays welding its contacts together, but these always turned out to be excessive load downstream. You might want to compare the current draw between this douser and another one. Shorted turns come to mind.

The fuse idea is certainly a viable option, but I would worry that the "operator" would not know how to find or deal with a blown fuse in the middle of the night. With Zippers a 3/4 Amp Slo-Blo has been found to be about right. They will fatigue, however, and have to be replaced a couple of times a year.

Finally, there is the old dodge of wiring a 200 watt light bulb in series with the coil. The theory here is that because a tungsten filament lamp has an inrush current something like 14 times its operating current, the douser gets a good strong initial pulse which quickly becomes limited by higher resistance when the filament gets hot.

Paul, if you will e-mail me your mailing address I shall send you a TA-10 manual.

------------------
Bill Purdy
Component Engineering

Posted by Paul G. Thompson (Member # 655) on 09-27-2001, 01:24 PM:

Thanks, Bill.

The lightbulb thing is a good idea. I never thought of that one.

Paul

Posted by Freddie Dobbs (Member # 915) on 09-27-2001, 06:39 PM:

Paul,

We use to build DPM (Douser Protection Modules)with a cap, diodes and a relay, The Richard Rogers automations we used, ate x-overs all the time.. Let me know if you would like the schematic...

Posted by Gordon McLeod (Member # 33) on 09-27-2001, 08:51 PM:

I usually put a device called a QuenchArc across zipper contacts.

Posted by Paul G. Thompson (Member # 655) on 09-30-2001, 11:51 PM:

Gordon, I am not familiar with QuenchArc. What is it?

Posted by Gordon McLeod (Member # 33) on 10-01-2001, 08:20 AM:

A quench arc is an ecapsulated device that contains a self healing cap and a resistor. They can be placed across relay or switch contacts to prevent the formation of an arc when inductive loads are switched. because they are self healing they do not tend to blow out or short as others do
the caustionary note is that there is some voltage present on the output terminals all the time

Posted by Ken Layton (Member # 133) on 10-01-2001, 08:48 AM:

Sounds like the description of a "snubber" circuit.

Posted by Paul G. Thompson (Member # 655) on 10-01-2001, 01:55 PM:

Gordon, thank you for the information.

Paul

Posted by Gordon McLeod (Member # 33) on 10-01-2001, 09:27 PM:

It is a snubber but I have never had the thing short unike a lot of standalone ones

Posted by Paul G. Thompson (Member # 655) on 10-01-2001, 10:18 PM:

Gordon, since we are working with inductive reactance, I would presume the capacitor value might be critical. What would your recommendation be on capacitance and what size resistor would you recommend?

Paul

Posted by Gordon McLeod (Member # 33) on 10-02-2001, 07:48 AM:

If memory serves it is around .1UF 5,000vpiv and a 22 ohm resistor

Posted by Paul G. Thompson (Member # 655) on 10-04-2001, 01:19 AM:

Got my coil in, and replaced it. Just to be sure it was not a stuck relay that caused it, I swapped a few around.

I'll let you know if it fries again.

Paul

Posted by Paul G. Thompson (Member # 655) on 11-24-2001, 05:12 PM:

Brad, I should have taken your advice about adding a fuse in the CO circuit, or Gordon's recommendation about using a 100-watt light bulb. The same automation, in the same house, fried another CO open coil.

Any other suggestions?

Paul

Posted by Paul G. Thompson (Member # 655) on 12-03-2001, 12:27 AM:

Well, this weekend, I had a bad start on my 4:00 run. I forgot to turn on the platter take-up. When I started the show, naturally the TA-10 shut the system down. (great - just as advertized).

However, when I rolled up the film spewed on the floor, I attempted to re-start, followed by an immediate shutdown again. Once more a re-start, motor restarted ok, the film motion and film presence led's were lit on the fail-safe, but one film status LED's was "off" (I honestly can't remember which one it was...) on the automation. (no reason whatsoever.) Then, No. 3 shut down when the lamp in no. 2 finally fired, and the LED on the film status lit.. When #3 was restarted, the lamp on No. 2 went out, and it would not come on until I manually over-road it at the automation. The motor was running on automation, but the sound format had to also be manally over-ridden. At the end of the show, I brought it down manually, except for the motor. On film tail-out, the alarm went off again, and the motor shut down just like it was supposed to.

Did Bill Gates write the program?

I think two things happened here which was intially caused by my screw-up of not turning on the take-up motor.

1. The automation froze in the middle of the cycle. (This would account for the possibility of frying another CO Open coil.
2. The automations are talking to each other through space or the power lines. (they are not connected via any interlock circuit whatsoever). Seems kind of odd when one Xenon lamp fires, it shuts down another projection station without sounding an alarm.

Nice, huh? <I wander off talking to myself...> Hmmmm. I think I have a grounding problem.

Back again....Oh, by the way - I am using switcher power supplies for the Xenon lamps. Strong International type, driving 3000w lamps.

Anyway, now this is what I call "Bad Start".

Paul

Posted by Paul G. Thompson (Member # 655) on 12-05-2001, 01:25 AM:

Just an update.

It was reported to me today that the TA-10's in the two houses had a great day talking to each other, and shutting each other down like cats and mice. Starting up #2 would shut down #3. Then when #3 was re-started, it shut down #2. After trying to re-start #2, it again shut down #3. The projectionist got so frustrated she rebooted the whole damn thing, from the ground up. She finally got both No. 2 and 3 running.

So I went to the theater, pulled the covers off the power panels, and made a very careful inspection. I noted that the electricians forgot to pull a separate ground into the power panels, and the entire projection stations were basically "floating". Apparently there may be a loose compression fitting somewhere in the EMT maze in the ceilings and rafters which might be preventing a good ground to the projection station raceways, pull boxes, flex EMT, xenon power supplies, pedistals, etc.

I took a No. 8AWG wire and bonded the neutral to the ground, as the neutral was grounded anyway in the main distribution panel.

Then it occured to me that it may not have been the automations causing all this trouble. It may have been lamp ignition emitting a high level of RF (which they certainly do). The poorly grounded projection stations acted like huge antennas. I have a tendency to believe this RF was getting into the automation's CPU, and driving it nuts. I can also see that it might be possible for a CPU to get so confused that it closed the CO Open relay and fried its coil, just like these damned PC's and their "Illegal Functions and will now self-distruct, Press any key to continue".

So far, so good. There were no additional reports that came to me today saying that more shutdowns have occurred.

I think I found the trouble.

Time will tell.

Paul

Posted by Steve Guttag (Member # 268) on 12-05-2001, 08:07 PM:

Paul,

Please tell me you are going to go back and pull in the proper ground wires rather than leave the current neutral-ground thing.

Certainly the grounding issue must be resolved to clear the problem and while experimenting, anything goes but neutral/=ground except right after the step down transformer...hence on the first panel after the transformer, the Neutral buss and ground buss may be the same. It is also an indication that the panel is the first in the line of any further subpanels.

Once proper grounds are pulled in, noise supression will be significantly better for everything concerned, including sound and your rectifier's diodes. I, not too long ago, had a theatre where the diodes were failing at an amazing rate and they weren't overheated...come to find that the lamphouses had such a good paint job, the ground was compromised and that the caps in and around the igniter had nowhere to drain to...after using star washers on the lamphouses to ensure good ground to the chassis, problems vanished overnight.

Steve

------------------
"Old projectionists never die, they just changeover!"

Posted by Gordon McLeod (Member # 33) on 12-05-2001, 09:26 PM:

Also it is worth noting that under the NEC all raceways (because they are painted) and flex must actually have a ground wire bonding them to the emt or even better to the panel

Posted by Paul G. Thompson (Member # 655) on 12-05-2001, 09:55 PM:

Steve, you absolutely correct. The electrical contractor who wired that building is going to be saddled with that responsibility very soon, probably within the next day or so.

I was reluctant to even experiment with this thing. But one thing I can say - it is a new building, and the electrical contractor is the one who is going to get that building up to code. I don't know how it slid by the electrical inspector in the first place. It is a major job, and I don't have the equipment to perform such an operation.

Also, it is uncertain what was done in other sub-panels. As it stands right now, if we dump the main neutral and have a major load imbalance, all or very much of the EMT could come "hot"!

Gordon, you are also correct. Ground wires are pulled trhough the flex now. It used to be that if it was less than 5 feet, it did not need a separate ground.

Now, the real task is going to be getting all the hoop jumping, feet kissing, and finger pointing behind us so that this job can be finished correctly.

(and you know how that goes..)

Posted by Oscar Neundorfer (Member # 458) on 12-06-2001, 07:14 AM:

I am usually cloistered in my lab and do not get into the field nearly as much as the rest of you guys do, but what little I manage to get out there, I have seen horrendous wiring problems concerning grounding. Improper power distribution, especially in the grounding, can cause more wierd and apparently unsolvable problems than you can imagine. I have heard from too many people that even when the wiring is properly specified in the blueprints, that far too many electrical contrators simply ignore the plans and do it their way because they "know better". Add to that poorly done wiring plans, and you have a recipe for a nightmare.

In these days when so much of the electronics is microprocessor based, and when there are far more sources of EMI/RFI and all kinds of nasty spikes, harmonics due to computer switching supplies, etc. on the AC lines, it is absolutely imperative to have the best possible wiring and grounding done. Electricians need far more training on the problems and solutions regarding sensitive electronic equipment. Contractors need to learn to do things the right way and not "their" way. Building owners/cinema corporate people need to hold the electrical contractors' feet to the fire and not let them get away with ANYTHING wrong. There is just too much expensive and sensitive equipment in projection booths to settle for anything less than a first class power distribution system. I believe this will correct many of today's problems.

------------------
Oscar Neundorfer
Chief Engineer
SMART Devices, Inc.

oscar@smartdev.com

Posted by Paul G. Thompson (Member # 655) on 12-09-2001, 07:29 PM:

This sounds almost like a weekly update.

For the most part, the grounding did take care of the problem. But one more problem popped up. Manual shutdown or fault shutdown on one machine took out one of the other machines, too.

After banging my head on the wall, I looked up and saw that a strange pipe was also coming out of the speaker wire pull boxes on the wall. All of the speaker wire pull boxes were connected together.

Hmmmmmm....Seems as though the installer used the speaker wire pull boxes as a non-sync feed from the other projection stations. Also, I noticed a Beldon 8451 cable interfacing all of these pull boxes. I followed the wires out, and those wires went into the automation. After yanking the covers off the TA-10's, the 8451 was connected to the "Data port" terminals.....

Since we don't and never will use this option, I disconnected all of those wires to the data port terminals on all automations.

Between the grounding problems and this data port thing, it has been a rollercoaster ride to find out what the hell was wrong.

Things seem to be running normally now, except for the igniter in No. 2 sometimes does not ignite, and the motor on No. 3 takes to long to build up to speed. Film Motion Fault shuts it down. But these two problems have also been with us since day one, so those are different problems to solve in the near future. There are lots of other minor problems that have to be addressed, such as movable masking that doesn't want to move, some more platter motors that are in poor shape, mis-cut aperatures, things like that.....

I am beginning to think this was a bad installation.

I am glad I had nothing to do with it.

Paul

Posted by Paul G. Thompson (Member # 655) on 12-15-2001, 03:24 PM:

Update: The disconnection of the Data Port terminals corrected the problem of the TA-10's talking to each other and driving everyone nuts.

I still wonder why the data port cables were pulled through the speaker wire raceways......Arg! I would never do that.....

I also removed the bonds between the neutral and grounds that I installed in the power sub-panels. But we are still waiting for an electrician to get us up to snuff.