Film-Tech Forum ARCHIVE: Strong Console Igniter Burnt Up question

This is topic Strong Console Igniter Burnt Up question in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Bernie Anderson Jr (Member # 410) on 12-21-2011, 10:42 PM:

So tonight, I'm told that there was a problem in one of our theaters and this was the result.

Of course, this is days before Christmas weekend.

Anyway, this is from a Strong (ORC Clone) Console (not sure of the model). What would cause this to happen? If I replace the ignitor and cable, do I need to worry about it burning up again because of something else in the power supply? I've only seen something similar where the cable burnt up only.

Bernie

Posted by Dave Macaulay (Member # 813) on 12-22-2011, 07:57 AM:

First, that's not any Strong igniter I've ever seen. I may not have seen them all.
This kind of damage is typical of a loose connection, as is a burnt cable end. There are a lot of amps through those connections, so a very low contact resistance will produce a lot of watts of heat. This could be a poor crimp connection between the cable and terminal, more commonly it's a loose nut on the igniter lug post.
I often clean the metal contacting surfaces with something like fine sandpaper or steel wool. Note that the way this one's connected the current has to pass from the igniter lug and nut through the flat washers to the wire terminal, so they should also be cleaned. In my opinion the correct practice would be to have the cable terminal directly on the igniter post - no washer below it - with one flat washer and a spring washer above it then the nut. This gives direct metal-to-metal contact between the igniter lug and wire terminal. The nut has to be tight enough to fully compress the spring washer. Toothed washers as used in your picture are inferior to spring washers in this use.

Posted by Mark Gulbrandsen (Member # 72) on 12-22-2011, 09:45 AM:

The ignitor may actually be ok. Try replacing the cable... hey, film doesn't have much time left anyways!!
Hint... I've actually run shows with automotive jumper cables attached... temporarily.

Posted by Bernie Anderson Jr (Member # 410) on 12-22-2011, 10:17 AM:

Thanks guys. This lamp house is weird to begin with. THe original design was an ORC Optimax II and I guess Strong bought them and continued to make these consoles under the name of Strong Optimax DV2000. Its the same console but with different color paint. Inside is the same .

I know... film is coming to the end, but this is an independent art house which is going to the bitter end with film as long as they can. At the moment, its "repair it with whatever we have in the parts pile"

Thanks

Bernie

Posted by Robert D Hall (Member # 5674) on 12-22-2011, 10:58 AM:

I dont think that was from a loose nut. Every time i have seen a (melt down) from a loose nut the washers have a lest started to melt or discolor. The washers in the pic look fine. Looks more like the arc or heat was coming from in side the ignitor.

Posted by Rick Raskin (Member # 1561) on 12-22-2011, 02:33 PM:

Looks like a bad crimp to me. Any of you guys ever use No-Ox compound on these? That was common practice in the phone factory where DC leads could carry 100s of Amps.

Posted by Gordon McLeod (Member # 33) on 12-23-2011, 12:36 AM:

Most of the strong version of the ORC ignitors did that and it usually indicated that the tesla coil that is potted insode melted down
those ignitors are brute force so any ignitor that will fire positive ignition will work

Posted by Louis Bornwasser (Member # 3063) on 12-23-2011, 09:35 AM:

I, too, think it is just the crimp because the washers look good. The coil inside is all one piece, except the ends. I would replace the wire and try.

The super lumex version of the strong igniter is a large coil in a box. I have NEVER had the large coil fail (boxes break and then we repot in a new box).

Posted by Richard Hamilton (Member # 321) on 12-23-2011, 12:47 PM:

Call Strong and ask for Dale McMillin. If I remember correctly, he worked for ORC before Strong. One of the smartest (and nicest) guys when it comes to lamphouses and power supplies.

Rick

Posted by Bernie Anderson Jr (Member # 410) on 12-24-2011, 03:00 AM:

Thanks guys. I got it working. I replaced the whole thing with a back up that I had and a new cable. But I kept the old one. If you say it will work, I'll keep it as a back up.

What exactly does that coil work in the ignitor?

Posted by Randy Stankey (Member # 64) on 12-24-2011, 10:51 AM:

Are you asking what the coil is or are you asking why you need an igniter in the first place?

In a xenon lamp, you have a 1/4" gap between the electrodes surrounded by a non-conductive gas. It's essentially an open circuit. You can't get electricity to go across the gap. Of course, if there's no electricity flowing, there's no light.

But, if you ionize the gas it becomes conductive, electricity can flow and there will be light. However, it takes several thousand volts in order to ionize that gas and make it conduct.

The igniter is the thing that generates that voltage which ionizes the gas inside the lamp. It makes about 30,000 volts!

In your case, that coil is the thing that acts as a transformer to generate the needed voltage.

This is the reason your electrical connections need to be properly tightened and, in your case, lack of secure connection is, presumably, what caused the failure.

Posted by Monte L Fullmer (Member # 2797) on 12-24-2011, 05:50 PM:

Like for us old-timers striking up a carbon arc lamphouse: throw the DC switch, touch the rods together to make a complete circuit, then retract the rods to the proper gap and the "ball of light" between the two rods keeps the circuit complete.

Posted by Bernie Anderson Jr (Member # 410) on 12-28-2011, 02:37 AM:

Randy, Really? [Big Grin]

I didn't know how the coil functioned in the circuit. Safe to say that the coil functions more as a large capacitor than a transformer?

Posted by Ian Parfrey (Member # 5122) on 12-28-2011, 03:03 AM:

More like an inductor per chance?

Posted by Gordon McLeod (Member # 33) on 12-28-2011, 08:52 AM:

No it is a teslacoil which is a very high ratio step up transformer for very high voltages it takes 5-10KV input and steps it up to around 30Kv The inductance of the input windings and the caps make a tuned circuit which the noise generated by the spark gap excites to provide the hi frewuency and high voltage needed to ionize the gas in the lamp