This is topic Igniter problems? in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.
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Posted by Joe Redifer (Member # 3) on 10-12-2002, 03:16 PM:
I have been contacted to help solve a problem in another state over the phone. I do not yet know exactly what equipment they use. They cannot get the bulb to ignite. According to them, both the ignter and the bulb are new. They "get a spark" when trying to ignite it manually.Any ideas I should tell them?
Posted by Ken McFall (Member # 845) on 10-12-2002, 03:49 PM:
Are they getting any spark when they try to strike the lamp. If there's no splash sound or spark is the ignitor wired in correctly there may have been a subtle change in the wiring terminals. Do they have automation or is it manual strike, are the lamphouse interlocks all working correctly when the sides are closed.
Depanding on the setup they should be able to hear the contactors close as they turn on, if not suspect the side interlocks.
Are the DC leads near or touching any part of the casing, try turning the lamp slightly to move the leads away from metal casing etc, orcon are very poor in this respect.
Have they tried another lamp, it's not unheard of for a lamp to be faulty out of the box!! But never Osram I'm sure 
couldn't resist that sorry....
More to follow as the Gin & Tonic flows ....
Posted by Paul G. Thompson (Member # 655) on 10-12-2002, 04:10 PM:
Joe, ask them to put their ear close to the powere supply and listen for the contact closure. If they cannot hear the contactor close, I would suspect an air flow or safety interlock problem. If the contactor does close, something could be wrong with the power supply.
Also, if the lamphouse is equipped with volt meter like some are, ask them to look at the voltage indication. Depending on the type of power supply, the open circuit voltage could be anywhere from 75 to 130 volts. (somewhere in that ballpark figure)
Posted by Darryl Spicer (Member # 711) on 10-12-2002, 04:14 PM:
Normaly when an interlock is open there is no spark or anything for safety reasons. Check diodes, if one is open allowing fliow in both directions can sometimes cause this with out triping breakers. They need to double check and make sure the start voltage is pegging over 120volts. edit,
or as paul just stated make sure the start voltage is within the range depending on the rectifier unit.
Posted by Joe Redifer (Member # 3) on 10-12-2002, 04:25 PM:
Yeah there is contact closure and there is air flow. Also checked to see if the bulb had any wires sitting too close to the reflector or any other metal parts (that happened to me once). All checks out. I assume it is a diode or a power supply problem which I cannot fix over the phone. Unfortunately they have no techs so they'll have to work something out.They have, according to them, "Christie lamphouses that are probably about 35 years old".
Posted by Paul G. Thompson (Member # 655) on 10-12-2002, 04:46 PM:
Those were very troublesome power supplies. Have him check the tap switch. chances are, it is burned up.
Posted by Brad Miller (Member # 2) on 10-12-2002, 05:17 PM:
Have them lower the tap setting one notch and wiggle it around to make sure it is well seated. Seen it happen a lot on those older style Christies.
Posted by Gordon McLeod (Member # 33) on 10-12-2002, 06:11 PM:
Have them measure the noload voltage on the output terminals of the rectifier
Also can they see the spark in the lamp itself through the view port
Posted by John Pytlak (Member # 331) on 10-16-2002, 09:02 PM:
To measure the load / no load voltage, use a DC meter that won't be damaged by the high voltage ignition pulse that may not be completely snubbed by the rectifier filter circuit.Optimum load (operating) and no load voltage ranges (prior to ignition) are usually specified by the lamp manufacturer.
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Posted by Jonathan Worthing (Member # 803) on 10-18-2002, 03:50 AM:
can they see the lamp trying to strike or do they say that it sounds like it is striking.They may be confusing lamp striking with ignitor spark gap striking.
I have seen a striking lead arc against a mirror holder which looked like a strike flash.
I hate this kind of question. No matter how hard you try you never get all the facts over the phone.