Control/Dimming Electro Controls EC Quad Dimmer help

[Binski99]

I do sound and lighting for my high school and we have an ECMUX system. We use a DMX board that runs into a protocol converter to get it to ECMUX. We have EC Quad dimmers. They are 4 channel dimmers. They look like this http://www.johnsonsystems.com/parts/QD-Q24KW_large.jpg

I am having some problems with these dimmers. Some channels wont turn on some will not turn off. Some dim but do not turn all the way off. One of the dimmer pack's Ramp light wont turn on. The Drive lights also do not come on when pushing the fader up. The line and load lights come on but no ramp or drive. No lighting fixtures on that pack turn on. Any idea of what the problem may be? Firing card? SCR? I am up to somewhere around 10 channels that are not working properly plus the one dimmer pack that has the ramp and drive problem. Any ideas?

 

[millamber]

By dimmer pack do you mean the quad module? The thing in the picture is a module that fits in an EC dimmer rack that is permanently installed. A pack generally means a portable system that can quickly be moved from space to space.

I hesitate to suggest any troubleshooting tips for this system as these things can be real tricky if you aren't sure at what you are looking. The best and safest advice I can offer is to see if your school's maintenance department can setup a service call with a dimming professional.

Welcome to the Booth!

 

[Binski99]

By dimmer pack do you mean the quad module? The thing in the picture is a module that fits in an EC dimmer rack that is permanently installed. A pack generally means a portable system that can quickly be moved from space to space.

I hesitate to suggest any troubleshooting tips for this system as these things can be real tricky if you aren't sure at what you are looking. The best and safest advice I can offer is to see if your school's maintenance department can setup a service call with a dimming professional.

Welcome to the Booth!

Yes I mean the module that fits in the rack. I am just looking for what people might think it is. I want to come up with an estimate for the repairs to give to the drama director. Most likely the drama club will be paying for the repairs. I do know how to take the modules out of the rack. They just slide in and out. As of right now I just keep swapping the modules around in the rack until I get the lights I need to work working. Sometimes I have to move 4 or 5 of them, but that was before we had this many bad channels. Now it is pretty much impossible to get all of the lights I need working.

 

[derekleffew]

Binski99 , try contacting one of the vendors at Service and Repair Vendors for an estimate.

 

[Binski99]

Thanks guys I am going to send out an email to a local lighting company and see if they can fix it and what it will cost. Hopefully they are willing to come out because they are about 2 hours away. I heard they have worked on our dimmers before but it has been a really long time.

 

[derekleffew]

Good luck with that. But if it's the modules and not the rack, that need repair, you'll likely find it less costly to ship the modules to Emlight, Lite-Trol, or other, rather than pay for travel time and field service.

Some more information about your dimmers here: The Electro Controls Archive . Surprisingly, looks like they use SSRs, so possibly not a very expensive or difficult repair. (Note the sheet is dated 1983.)

 

[MPowers]

TRY
Electro Controls Repair Services | Nyco Systems

I know nothing about them except they advertise working on EC products. A simple, toll free, phone call will let you know if they do what you need.

 

[derekleffew]

MPowers , I'm pretty sure that's a different Electro Controls--Electrol Controls, Inc., and not the stage lighting company from Salt Lake City, UT, purchased by Strand in 1986. Some revisionists have tried to distinguish between the two by writing the stage lighting company as ElectroControls, but my research does not support that. See also http://www.electrocontrolsarchive.blogspot.com/, by CB member 2madmax.

 

[Binski99]

Good luck with that. But if it's the modules and not the rack, that need repair, you'll likely find it less costly to ship the modules to Emlight, Lite-Trol, or other, rather than pay for travel time and field service.

I am not really sure if it is the rack or the modules. I think it is the modules but am no expert. Could be both I really don't know for sure. The system was installed in the early 80's from my understanding maybe earlier so their could be a number of things wrong. We will probably have someone come out because this year we cut some costs. We don't need to rent costumes this year and we bought wireless mics last year so we no longer need to rent them. This cuts should free up some money to get someone out to look at it.

 

[DimmerDotCom]

I am not really sure if it is the rack or the modules. I think it is the modules but am no expert. Could be both I really don't know for sure. The system was installed in the early 80's from my understanding maybe earlier so their could be a number of things wrong. We will probably have someone come out because this year we cut some costs. We don't need to rent costumes this year and we bought wireless mics last year so we no longer need to rent them. This cuts should free up some money to get someone out to look at it.

If you do not have a drive light then the dimmer channel is not receiving a signal to turn on or the firing card is defective. The neons work in inverse of the load level but they often burn out so are not a reliable standard to depend on. Since you mention EC-MUX, you must have decoder card (cards with a either a linear or rotary slider). They control the dimer outputs in groups of 32 in a mu,erical fashion (1st card=1-32, 2nd card-33-64, etc). With no input to the rack or with the RS422 card removed, you should be able to press the top button on the decoder card to cycle every dimmer on in sequence everytime you hit the button. At the end of 32 all should turn on and then the next press all should turn off. The slider is the level the dimmer should turn on at. It can be used a rudimentary panic even (if you are patient).

The dimmers use SCR's not SSR's. The dimmer s often fail because they do not seat correctly in the rack. Only the gen 1 scr's really failed and when scr's go they usually burned up in this rack. If you are troubleshooting this yourself, swap dimmers carefully as to not damage the rear anderson connectors. Or by a JSI firing card to get one good working confirmed dimmer to base the other ones off of. The ramps are generated by the card at the bottom of the rack with just LEDs on it. If a card is out, none of the dimmers in that phase will show a phase light.

Opening the access panel (if available in your rack since many of these racks are semi custom) above the first row of dimmers will show you all the analog channels of every dimmer. Verify proper wiring (i.e. not broken or missing) and you can check your control levels there too. Lots of live voltage in there so only service if you are experienced working around potentially hazardous voltages in a confined space.

 

[Binski99]

Thanks for the info we have the cards with the rotary. I was told by a previous student that did lighting back in the early 90's that their board went out once and they had to resort to those rotary knobs to somehow over ride the board to control the lights. It got them through the show it didn't look that great but they got through it.

I do know how to swap dimmers. After the system was installed the someone took all the screws out that hold the dimmers into the rack so they could access the dip switches inside to switch them to ON/OFF rather than dimming by just sliding them out.

The only time I open that panel above the top dimmers is when I have to swap the dimmers in the first row because the they will not go in unless you open it.

I will not mess around with the stuff in the access panel. I am just a student not a trained service person. I will check to see if the lights on the card at the bottom are all on. It will be about a week and a half till I can get in their to check. I will also take on of our dimmers that I know for sure work and put it in the place of the one that does not work.

derekleffew, thanks for the info on the dimmers.

 

[el_jefe]

Hi. I’m new to the forum, and I’m the director of education at a nonprofit makerspace and I also have recently started doing live sound production.
I won a whole rack of these in an auction and was wondering if (a) they might still be worth something, or (b) if there would be anywhere I could find schematics to identify components easier.
I got the whole thing so cheap that if anyone is in the St Louis area and wants the whole thing as-is for like 50 bucks you can have it. I’d think you could make a profit on that even selling it for scrap, especially with the large copper rails in the back of the rack.
Either way, any help would be appreciated. Thanks!

 

[microstar]

If you are talking about the Electro Controls Quad dimmer rack as pictured below, those individual dimmer modules are so heavy they are hard to sell on eBay. If you do so, just make sure you calculate an accurate shipping cost. Certainly do not rely on the eBay shipping calculator. The real value is in the control cards in the bottom card cage. All but the right-hand one (the power supply card) are very lightweight and are desirable for keeping old systems running. Since you don't know or have any way to test, I would list them individually for $50-$75 each.

 

[el_jefe]

If you are talking about the Electro Controls Quad dimmer rack as pictured below, those individual dimmer modules are so heavy they are hard to sell on eBay. If you do so, just make sure you calculate an accurate shipping cost. Certainly do not rely on the eBay shipping calculator. The real value is in the control cards in the bottom card cage. All but the right-hand one (the power supply card) are very lightweight and are desirable for keeping old systems running. Since you don't know or have any way to test, I would list them individually for $50-$75 each.
View attachment 24804

Yeah, that's it!
I was going to see if maaaybe I could sell locally but seems like a pretty small market, so then thought about the possibility of maybe repurposing parts. If I can sell those cards for even $50 each, I'd be okay with even giving the rest away.
For those cards, would it be possible to test them with a multimeter?
Oh, and do you think there would be much of a market for Lightronics demultiplexers (DMX-24)? I got 2 of those with the lot as well.
Thank you!

 

[microstar]

Yeah, that's it!
I was going to see if maaaybe I could sell locally but seems like a pretty small market, so then thought about the possibility of maybe repurposing parts. If I can sell those cards for even $50 each, I'd be okay with even giving the rest away.
For those cards, would it be possible to test them with a multimeter?
Oh, and do you think there would be much of a market for Lightronics demultiplexers (DMX-24)? I got 2 of those with the lot as well.
Thank you!

No, you can't really test the control cards with a multimeter, far too complex. You basically need to power the entire rack up, supply the control signals (either ECMUX or analog 0-15vdc) at the terminal input area below the blower,
then check the output of each individual dimmer for 0-120vac with a RMS reading voltmeter or an incandescent lamp load. Not recommended unless you have previous experience with these racks.
I've seen the Lightronics DMX-24's on eBay fairly regularly. Not in great demand, but price them low enough and someone will buy them! Go to "Advanced Search" at upper right corner and look up units that have been sold.
Remember the Electro Controls Quad rack is about 40 years old now!!

 

[el_jefe]

No, you can't really test the control cards with a multimeter, far too complex. You basically need to power the entire rack up, supply the control signals (either ECMUX or analog 0-15vdc) at the terminal input area below the blower,
then check the output of each individual dimmer for 0-120vac with a RMS reading voltmeter or an incandescent lamp load. Not recommended unless you have previous experience with these racks.
I've seen the Lightronics DMX-24's on eBay fairly regularly. Not in great demand, but price them low enough and someone will buy them! Go to "Advanced Search" at upper right corner and look up units that have been sold.
Remember the Electro Controls Quad rack is about 40 years old now!!

Yeah, I figured it might be difficult to find a buyer.
Thanks for the info, I appreciate it!