Need help controlling antiquated school stage lighting system

[tvanbuskirk]

I do lights for a school that has an antiquated lighting panel the size of a small car that is hard wired in place backstage. I want to insert small dimmer packs between the border fixtures and the panel so that i can use an xlr controller to dim them remotely. The connectors are all stage pin, and the border lights are arranged as follows in three rows: 3x15 lamps, 3x15 lamps, and 4x10 lamps. What is the most cost-effective way to do this? There is no front of stage lighting in house. I normally rent a combination of about 8 source 4 ellipsoidals and PAR lamps, with dimmer packs, that I hang on crankstands, and I control these from a board out front. I have separate 20 amp circuits that I had installed for those. But I have no way of controlling the border strips, so I have have to either leave them on for the whole show, or not use them at all. Disconnecting the existing console is not an option, so my thought was leave the old console full-on and insert rented DMX-controlled dimmer pack right before each border fixture. The I could control the borders and the rented FOH lights from one lighing board. But I need to make sure this will work before I just start buying gear. Any thoughts or suggestions?

 

[VCTMike]

If you mean you'd like to insert the (shoebox?) dimmer packs between the old dimmer system and the border lights I doubt the new dimmer packs would like that unless the old dimmer can be set to a relay or constant power on output. Also depending on the lamps used in the border lights and the combinations used the per/channel load may be too high for the assumed shoebox dimmer packs.

 

[derekleffew]

... and the border lights are arranged as follows in three rows: 3x15 lamps, 3x15 lamps, and 4x10 lamps. What is the most cost-effective way to do this? ...

Sounds like you need at least ten dimmers. What is the wattage of each borderlight lamp? Probably 100W. So you need 1000W-1500W dimmers. If you must keep your dimmer, autotransformer board, the only thing I can think of would be 10 of these: Dimming & Control: Slim Dimmer Plus 1800W | Lex Products .

But it's not a cost-effective solution. Better, and less expensive, would be to replace the existing board with a 12x2.4kW DMX dimmer pack.

...But I have no way of controlling the border strips, so I have have to either leave them on for the whole show, or not use them at all. ...

Two operators: One backstage running the X-Rays and one FOH running the frontlight, in communication with each other via headset. It's the way many, many shows use to be run, and some still are today.

 

[venuetech]

Questions
what is the wattage of the border light lamps?
on each border you have three stage pin connectors?
do you have any photos of this "Small Car"
does the control board have large (hand size) levers or small (finger size) sliding pots?

Photos would be a help.

If the old control has 0-10V (control signal) dimmers. a converter could be installed allowing you to have dmx512 control of them.

 

[tvanbuskirk]

Well here's the thing. The old dimmers are 50 yrs old, they are mechanical dimmers operated by hand, with big levers like something out of Frankenstein. As for the per-channel load, each channel in each row is 8-9 amps.

 

[tvanbuskirk]

the lamps are 60W (sorry, thought I said that in the original post)
each border has three stage pin connectors - 1 for each color (R,Y,B)
i will try to photograph and post here
control board has large hand size levers
it dates back to around 1960; it was made by Century Lighting.

 

[tvanbuskirk]

I have limited manpower, and it is hard to change colors on the backstage panel; it is pretty old and unwieldy, so that is my last resort. And as for it being cost-effective, I was thinking of renting the dimmers rather than buying them, as I only need them for a few days each year.

 

[venuetech]

In that case I would echo Derek's solution

But it's not a cost-effective solution. Better, and less expensive, would be to replace the existing board with a 12x2.4kW DMX dimmer pack.

or a second operator backstage.

Get a qualified electrician to do the power hookup.

 

[tvanbuskirk]

Here are photos of the unit. Replacement is not an option. House lights and who knows what else runs through it, along with my lights. It was installed in 1954. Autotrans bd (seven 4 kw + three 4 kw house).Modified Century 2C configuration; no plugging panel. (that according to a source I found online)

 

[DrPinto]

Wow. That old board is in great shape! I would run everything from that backstage. If I'm reading your post correctly, your strip lights are drawing about 7,800 watts. Your board can handle 52,000 watts. You would have to find out how many house lights you have, the wattage of each, and how big the circuit breakers that power this board are. If the breakers can handle the load and you could patch the 8 ellipsoidals you set up in the house into this board, you'd be all set.

 

[DrPinto]

Here are photos of the unit. Replacement is not an option. House lights and who knows what else runs through it, along with my lights. It was installed in 1954. Autotrans bd (seven 4 kw + three 4 kw house).Modified Century 2C configuration; no plugging panel. (that according to a source I found online)

The information you found online was probably from this site:

Century Lighting, Inc. Theater lighting control system drawings [archival material], 1950-1971

This is a collection at the Penn State University library. They have original project folders for Century Lighting installations from the early 1950's through the early 1970's. It would be worth your while to contact them and see if you could get your hands on any documents relating to the installation of your system. You may discover wall outlets, floor pockets, or other outlets you didn't know existed before. It's worth a try.

 

[tvanbuskirk]

Wow indeed, and thanks for the response. I probably should have expected your answer, but it is not ideal for me for several reasons. 1) I can't see at all from there and I need visual cues. 2) The backstage area is crowded and there really isn't even room to stand there during shows. 3) A couple of the dimmers don't work at all and others trip breakers on the panel all the time. 4) The dimmers that do work are sticky and hard to fade, and they are noisy - they squeak and thud. In other words, the panel is not as good as it looks.

That's why I was wondering if I could insert electronic dimmers between the old panel output and the fixtures. Then I would have DMX control for everything at the back of the house like I am used to.

The strip lights are in three rows: the first two are linked together as amber1, red1, and blue 1, so each comprises 15 60W lamps. The third row is 40 lamps divided between amber2, red2 and blue2, although blue2 is a circuit that does not work.

There are also house spots in the auditorium ceiling that run through the panel, as well as some unused circuits labeled stage spots that used to have some old fresnels connected to them. the old instruments disappeared one day; i guess someone thought they were junk.

The frustration is that i have plenty of power to run everything, but no way to control it through a modern DMX board, and by that i mean post-1980. All I really want to know is will the power coming out of the old panel - from the dimmers that control the strip lights - fry or otherwise corrupt any dimmer packs that I insert before the fixtures? Assuming i could rent something with enough capacity, like Leprecon 360s.

Most people who responded assumed I had electronic dimmers already in there, which is not the case. If everything on the old panel is set to full on, can i insert a dimmer pack and use the old panel as if it is just a power source?

 

[tvanbuskirk]

Yes, thank you. That is where I got the information. We have discovered floor pockets as well as footlights - I forgot to mention those - that are connected to the strip lights. They work but I don't use them. I don't know about the floor pockets. I will definitely reach out to them.

 

[BGW]

It's certainly not an ideal situation, but I think you should be able to do that. You'd obviously need a stage pin the Edison converter, and several of its mates for the other end. You'll just need to make sure that no one bumps the levers. Those old systems are transformer-based, so they put out nice clean power. Electrically it shouldn't be an issue. You'll need a couple of shoebox dimmers (~4 channel), though, not one large unit.

 

[DrPinto]

I see what you're trying to do, but I wouldn't do it. How many amps are the individual stage circuit breakers? It's hard to tell from the picture. If each circuit had a 15 amp breaker on it, the shoebox dimmer would be limited to a total of less than 1800 watts of instruments that you could plug into them.

If I was in this situation, I would convince the owners of the school to pay to have the old board looked at. It may just need long overdue maintenance. Those old boards were pretty tough from what I've heard. I would sell it from a safety point of view. If you have breakers tripping, it really should be looked at.

Ideally, replacement would be the way to go, but you have to do what you can with the funds available.

If the board is serviceable, you can just mount a camera in the house and use a monitor to see the stage action.

By the way, the stage plugs you have are 3 pin, correct?

 

[Nelson]

Yeah, I'd love to have an old console like that backstage in our auditorium, if for no other reason, to use as a backup.

 

[venuetech]

well you do have the power. it may be best to have a qualified electrician set up a small sub panel to feed your shoe box dimmers.
It is likely the folks you rent from can give you the name of a good electrician who would be familiar with theatrical issues.

 

[carmellights]

do not hook up dimmer packs to the outputs from the Autotransformer circuits - yes it will fry them..if they worked at all. if it was me, i would rent a portable Sensor pack ( 24 x 2K ) - have a qualified electrican tie in feeder for you at the power mains that is supplying the Autotransformer, and run some soft stage pin up to the strip lights - daisychain the Sensor pack to your console output and thats it. unfortunattly with Auto's there isnt really any legit way to use their output to power packs..or anything other than an incandescent load.

C

 

[carmellights]

Wow indeed, and thanks for the response. I probably should have expected your answer, but it is not ideal for me for several reasons. 1) I can't see at all from there and I need visual cues. 2) The backstage area is crowded and there really isn't even room to stand there during shows. 3) A couple of the dimmers don't work at all and others trip breakers on the panel all the time. 4) The dimmers that do work are sticky and hard to fade, and they are noisy - they squeak and thud. In other words, the panel is not as good as it looks.

That's why I was wondering if I could insert electronic dimmers between the old panel output and the fixtures. Then I would have DMX control for everything at the back of the house like I am used to.

The strip lights are in three rows: the first two are linked together as amber1, red1, and blue 1, so each comprises 15 60W lamps. The third row is 40 lamps divided between amber2, red2 and blue2, although blue2 is a circuit that does not work.

There are also house spots in the auditorium ceiling that run through the panel, as well as some unused circuits labeled stage spots that used to have some old fresnels connected to them. the old instruments disappeared one day; i guess someone thought they were junk.

The frustration is that i have plenty of power to run everything, but no way to control it through a modern DMX board, and by that i mean post-1980. All I really want to know is will the power coming out of the old panel - from the dimmers that control the strip lights - fry or otherwise corrupt any dimmer packs that I insert before the fixtures? Assuming i could rent something with enough capacity, like Leprecon 360s.

Most people who responded assumed I had electronic dimmers already in there, which is not the case. If everything on the old panel is set to full on, can i insert a dimmer pack and use the old panel as if it is just a power source?

do not hook up dimmer packs to output of these autotransformers - it wont work. get an electrician and rent a good capacity Sensor 24x2K pack. plug the individual strips into the pack - hook up DMX from console and there ya go. Auto's put out variable A/C ..not the nice 120 volts you want for supplying portable packs. C

 

[Chris15]

I'm sorry but I don't agree.

Autotransformers by their very nature are passive devices and have no significant effect on the waveform transferred through them.
An auto transformer at 100% will have the output identical to the input.