Kliegl Bros. Type SP Patch Panel

microstar

Well-Known Member
Joined
Jan 19, 2014
Location
Lawton, OK
If I had to guess, the problem is overvoltage from the dimmers being out of calibration.

Pulling the details out of my long-term memory: Those dimmers are all analog - with firing cards located in the modules. A bad capacitor on the firing card can result in the calibration going all out of whack. Or they could just drift over time.

Hopefully somewhere in the dimmer room there is a Kliegl test bench which will allow you to calibrate the dimmer modules outside of the dimmer rack. The test bench that I used had built in output AC meter, DC control voltage meter, control slider and sockets for load lamps. You would adjust two trim potentiometers on the firing card to get the correct output voltage from the appropriate input control voltage with the appropriate load applied.

The test bench had exposed high voltage contacts, so appropriate precautions should be taken while in use.

Maybe some of the older Control Booth folks have a copy of the calibration instructions - I remember that it was a finicky process. I think we calibrated so that a 10v input gave 120v output and 5v input gave 80v output.

If you don't have a test bench, calibration could still be done but it would be a much longer and more laborious process.

-Todd
I think most of the Kliegl analog dimmers were 0-28vdc, not 0-10. I know the R80 dimmers were.
 

ETCFIELDENG

Lin Wheeler ETC, Inc.
Joined
Oct 25, 2007
Location
Atlanta
Thanks for having me. I have been working in the local TV broadcast business for almost 20 years at stations in Western NY and North Carolina, before moving to Georgia.

I work at a TV station that still has a Kliegl Bros Type SP patch panel in use. It is connected to a "newer" SmartFade ETC lighting board. We have been running into an issue with our bulbs blowing prematurely. The fixtures that we are using are Mole 3081, 5421, and ETC Source 4's. The bulbs are not blowing like a typical bulb does.... they are melting inside the glass. My ENG Dept has went and checked fixtures and the drops from the grid. Everything is pointing back to the Kliegl Type SP. Any help would be great, I can't keep feeding the monster bulbs.
Hi Glossy, Where in Georgia are you located?
 

jhochb

Active Member
Joined
Jan 4, 2010
Location
Ft Lauderdale FL
Thanks for having me. I have been working in the local TV broadcast business for almost 20 years at stations in Western NY and North Carolina, before moving to Georgia.

I work at a TV station that still has a Kliegl Bros Type SP patch panel in use. It is connected to a "newer" SmartFade ETC lighting board. We have been running into an issue with our bulbs blowing prematurely. The fixtures that we are using are Mole 3081, 5421, and ETC Source 4's. The bulbs are not blowing like a typical bulb does.... they are melting inside the glass. My ENG Dept has went and checked fixtures and the drops from the grid. Everything is pointing back to the Kliegl Type SP. Any help would be great, I can't keep feeding the monster bulbs.

Good Morning Glossy

With a system this old I would check to see if ALL contacts are tight.
this would include
Connections to the fixtures
Connections inside the Dimmers, don't forget the Neutrals
Connections in the Patch pannel

Heating & cooling cycles often loosen contacts
loose wires inside connectors can cause arcing, over heating or ............


At the end of every leg of a long tour,we took a day or four to check the jumpers



I havent read all of the posts. so If I am repeating something
oops


Good Luck
 

BillConnerFASTC

Well-Known Member
Joined
Jan 30, 2010
Location
Clayton NY 13624
The easiest thing to check and perhaps eliminate are the voltages as Steve suggested. That was my first thought when I read your post. Maybe because until 15 or so years ago I specified tapped up feeds for 120 volt lamps in every facility - for over 20 years.
 

JD

Well-Known Member
Joined
Jan 1, 2005
Location
North Wales PA
PECO recently changed out the poles, wire, and transformers along the street where I work. For the heck of it, I just stuck my multimeter into the outlet next to my desk. 131 volts. At home, I usually measure 125 to 127. Nothing in the office looked any different than any other day. Photocopier, computers, LED office lighting, all couldn't care about the slightly high line voltage. The same cannot be said about incandescent lamps, especially studio lamps. Equipment and/or taps may have been changed in your area recently. You wouldn't necessarily know. Time to see what your line voltage is. The answer is as close as your nearest outlet.
 

RonHebbard

Well-Known Member
Premium Member
Joined
Jun 12, 2004
Location
Waterdown, ON, CA
PECO recently changed out the poles, wire, and transformers along the street where I work. For the heck of it, I just stuck my multimeter into the outlet next to my desk. 131 volts. At home, I usually measure 125 to 127. Nothing in the office looked any different than any other day. Photocopier, computers, LED office lighting, all couldn't care about the slightly high line voltage. The same cannot be said about incandescent lamps, especially studio lamps. Equipment and/or taps may have been changed in your area recently. You wouldn't necessarily know. Time to see what your line voltage is. The answer is as close as your nearest outlet.
@JD and @Glossy Shines Which circles us back to the beginning where I suggested inserting a two-fer, plugging a typical load into one leg of the two-fer. set your dimmer at 100% and measure the voltage on the free leg of the two-fer; measure with a moving iron / true RMS reading meter. Measure between hot & neutral, hot & ground and neutral & ground. The goal is to measure the voltage applied as close as possible to any / all of your lamps with the circuit in question UNDER LOAD, as opposed to simply measuring the voltage present with the circuit unloaded and zero voltage drops due to conductor lengths TO & FROM your source.
This may prove nothing or it may reveal a number of "interesting" problems / facts.
I believe this was where we began and we appear to have cycled back some 29 posts later.
Toodleoo!
Ron Hebbard
 
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Glossy Shines

Member
Joined
Sep 6, 2019
Location
Georgia USA
You and me both :). I am hoping to get some studio time with my ENG dept this upcoming week. I am eager to find out what the deal is and how to make it right. i can't thank everyone enough that has dropped knowledge bombs on me.
It's going to happen next week. The ENG team got the testing material ready. I will report all of our findings! I am super pumped!!!
 

Glossy Shines

Member
Joined
Sep 6, 2019
Location
Georgia USA
Did they get a calibrated power quality meter, or does it really take that long to get a true RMS multimeter?
We got up into the grid today between newscasts. We tested some of our "problem" fixtures first. We looked at some Mole Baby Redheads we use for back lights (they are bulbed down to 500W) and some Source 4's (575W & 750W) we use for architectural lights & back lights. every fixture came in between 113-118 with a full load. We still have fixtures to test; however, i was not expecting that result. I uploaded the pics of the test equipment. We had a homemade unit and a standard multimeter. I am dumbfounded by the results so far. What should we do next?
 

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microstar

Well-Known Member
Joined
Jan 19, 2014
Location
Lawton, OK
Your Ideal meter is not a true RMS meter and thus does not correctly measure the voltage from an SCR dimming system. I believe your actual voltage is much higher than your measurement, but I'm sure someone more knowledgeable will be along to correlate the average vs. rms voltages.
 

DrewE

Well-Known Member
Joined
Mar 18, 2019
Location
Vermont
Your Ideal meter is not a true RMS meter and thus does not correctly measure the voltage from an SCR dimming system. I believe your actual voltage is much higher than your measurement, but I'm sure someone more knowledgeable will be along to correlate the average vs. rms voltages.
At full on, the deviation from a sine wave for an SCR dimming system is ideally nothing and, in actual practice, not too much; so average responding multimeters (which is what this particular one is) give pretty close to correct results. At somewhat lower settings, the average responding meter will give significantly lower than correct RMS value readings, and return to near accuracy as the levels approach zero. Obviously at full off any meter worth its salt will read zero volts. I'd think at full on the results should be correct within a volt or two (or three or four, to account for possible inaccuracies in meter calibration).

I think the worst-case scenario is at 50% dimming (50% duty cycle or 50% power, which is not 50% brightness and may not be 50% on the light board) and the reading from an average responding meter is about 75% of the actual RMS value. Put another way, one must add a third again to get the correct RMS voltage. Note that analog meters are not (generally) true RMS meters, so the pictured power line monitor is no better than an inexpensive digital multimeter in this regard.

At any rate, true RMS multimeters are not all that expensive these days, and if you want to endear yourself to your ENG department and get more insight into what's going on with the lamps, maybe it would be worth getting them one.
 

FMEng

Well-Known Member
Fight Leukemia
Joined
Mar 31, 2008
Location
Tacoma, WA
Another thought here. Measure the voltage when the building HVAC load is low. It could be that the voltage is only high at certain times, like before the studio starts warming up, and before the heat of the day. A few minutes of high voltage can still kill lamps.

Electrical loads in the area around your building are also a factor. Maybe it's only high during the late evening news show, when the neighbors are not using much power. This is where a more sophisticated voltmeter with min/max hold can be left in place to log what is happening for 24 hours or more.
 

ETCFIELDENG

Lin Wheeler ETC, Inc.
Joined
Oct 25, 2007
Location
Atlanta
Hi Glossy, Please send me your contact info when you have a moment. Albenny is a little far but maybe a quick phone chat would work. By the way; I'm strictly a technician and I don't do sales or marketing. I'm also not selling service. Straight up chat that's all. It's a Boy Scout good deed type of thing.
[email protected]
 
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