I've been asked to come up with a wish list for one of the high school theaters I manage and some new lighting came to mind immediately. I'm looking into getting some LED cyc lights (Spectra Cyc 50s) to replace our current incandescent units, but I'd like to provide power to them using our existing circuits. Our lighting layout involves four fly lines wired into two CD80 AE racks with Strand C21 processors. The racks have 48 2.4kW dual dimmer modules on each. The idea is to swap out a circuit on each line so I have power available on a per-line basis.

My confusion lies in what kind of dimmer module I need to swap out to provide power to these and future LED fixtures. Am I looking for a non-dim module or constant power? What, if any, is the difference between the two? Will something like this work for my purposes? I notice the site also has a similar listing, but with "contactor non-dim/SSR dimmer" swapped. My hunch is that it's a mix of dim/non-dim, and the order just refers to which of the circuits is the non-dim?

I'm also concerned with future-proofing as much as I can. I don't know when the processors were installed on our racks, so I have no idea when to expect them to fail. I'm working on the assumption that I'm running on borrowed time right now, given the age of the school. Will the swapped dimmer module work with something like a Johnson Systems retrofit or will I need to purchase a module specifically for it? If the latter, then are there options that will work for both?

Please let me know if there's anything I can clarify, and especially if I've gone awry in my limited understanding of the hardware involved.
 
I've been asked to come up with a wish list for one of the high school theaters I manage and some new lighting came to mind immediately. I'm looking into getting some LED cyc lights (Spectra Cyc 50s) to replace our current incandescent units, but I'd like to provide power to them using our existing circuits. Our lighting layout involves four fly lines wired into two CD80 AE racks with Strand C21 processors. The racks have 48 2.4kW dual dimmer modules on each. The idea is to swap out a circuit on each line so I have power available on a per-line basis.

My confusion lies in what kind of dimmer module I need to swap out to provide power to these and future LED fixtures. Am I looking for a non-dim module or constant power? What, if any, is the difference between the two? Will something like this work for my purposes? I notice the site also has a similar listing, but with "contactor non-dim/SSR dimmer" swapped. My hunch is that it's a mix of dim/non-dim, and the order just refers to which of the circuits is the non-dim?

I'm also concerned with future-proofing as much as I can. I don't know when the processors were installed on our racks, so I have no idea when to expect them to fail. I'm working on the assumption that I'm running on borrowed time right now, given the age of the school. Will the swapped dimmer module work with something like a Johnson Systems retrofit or will I need to purchase a module specifically for it? If the latter, then are there options that will work for both?

Please let me know if there's anything I can clarify, and especially if I've gone awry in my limited understanding of the hardware involved.
@Wizard of Flaws I strongly recommend you phone Shawn Johnson, he often answers personally. Ask Shawn directly; have all your facts at the ready. I've always found Shawn patiently and thoroughly helpful as long as you're prepared, keeping up with him. and not unduly wasting his time.
Toodleoo!
Ron Hebbard
 
I've been asked to come up with a wish list for one of the high school theaters I manage and some new lighting came to mind immediately. I'm looking into getting some LED cyc lights (Spectra Cyc 50s) to replace our current incandescent units, but I'd like to provide power to them using our existing circuits. Our lighting layout involves four fly lines wired into two CD80 AE racks with Strand C21 processors. The racks have 48 2.4kW dual dimmer modules on each. The idea is to swap out a circuit on each line so I have power available on a per-line basis.

My confusion lies in what kind of dimmer module I need to swap out to provide power to these and future LED fixtures. Am I looking for a non-dim module or constant power? What, if any, is the difference between the two? Will something like this work for my purposes? I notice the site also has a similar listing, but with "contactor non-dim/SSR dimmer" swapped. My hunch is that it's a mix of dim/non-dim, and the order just refers to which of the circuits is the non-dim?

I'm also concerned with future-proofing as much as I can. I don't know when the processors were installed on our racks, so I have no idea when to expect them to fail. I'm working on the assumption that I'm running on borrowed time right now, given the age of the school. Will the swapped dimmer module work with something like a Johnson Systems retrofit or will I need to purchase a module specifically for it? If the latter, then are there options that will work for both?

Please let me know if there's anything I can clarify, and especially if I've gone awry in my limited understanding of the hardware involved.
C21's are very much current tech. You can easily get non-dim or relay modules for your rack to give you constant power.

.....and don't get the spectras. Chroma q color force ii 72's is what you want.
 
The dimming system should be fine for years, there really isn't much to break on them. The big thing is keeping them clean. Something that doesn't tend to happen very often if at all in high schools. As far as the LED cyc goes, you'll want a relay module for those. That way they'll be powered off unless your actually using them. You should be able to set your console up so that those relay circuits will be powered on when you turn the console on, and off when you turn the console off.
 
Depending on the height of your cyc, you might think about a SpectraCyc 100 instead of a SpectraCyc 50. Try to get a demo of both before you commit. They are great fixtures!
 
Some random thoughts...
The idea is to swap out a circuit on each line so I have power available on a per-line basis. ... My hunch is that it's a mix of dim/non-dim, and the order just refers to which of the circuits is the non-dim?
Please, resign yourself to the idea that it's going to be TWO circuits per location. Down the road you're going to be cursing when you need a "left" and all you have is "rights". Since it's a dual module, it can be set-up as Dimmer/Relay, or Relay/Dimmer. when built.
Am I looking for a non-dim module or constant power? What, if any, is the difference between the two? Will something like this work for my purposes?
Non-dim or Constant Power? Do you want/need power control of the fixtures AT THE CONSOLE? Is a trip to the dimmer rack once to turn them ON and once to turn them OFF per Day doable? A constant module is just the circuit breakers (and probably two fuses beyond the scope of this discussion). A relay allows on/off via DMX.

You don't want anything that says "SSR." Some claim to make a non-dim by telling the SSR to output either Full or Zero, nothing in between. But Full isn't really 100% and has a distorted waveform (beyond the scope) so some LED's and movers don't like them.

The CD80 AE rack has been out of production since 1992. I don't know where you'll find either a Relay or Constant Circuit module for the rack, unless "homemade" from a dimmer module as there are lots of those available. At least one thread on here talks about doing it yourself and virtually everyone saying yes it will work but it's a bad idea.
 
The CD80 AE rack has been out of production since 1992. I don't know where you'll find either a Relay or Constant Circuit module for the rack, unless "homemade" from a dimmer module as there are lots of those available. At least one thread on here talks about doing it yourself and virtually everyone saying yes it will work but it's a bad idea.

Johnson Systems offers both options. As well as pretty much anything else you would need to repair or update your CD80's to modern standards.
 
I believe what you really want is the Strand 76563BPR. It's a c21 module with a switch on both ciruits. The switch let's you select between relay power and dimmed power. You can have one circuit be a dimmer and the other a relay. Last time I bought them was two years ago and they were about $500 each. Call your local strand dealer or one of the major national dealers. Looks like they have gone up quite a bit.

If you don't need that flexibility in both circuits then a C21 Contactor Module will do. Contactors have relay only function in both circuits. These are a little cheaper.
 
Last edited:
I believe what you really want is the Strand 76563BPR. It's a c21 module with a switch on both ciruits. The switch let's you select between relay power and dimmed power. You can have one circuit be a dimmer and the other a relay. Last time I bought them was two years ago and they were about $500 each. Call your local strand dealer or one of the major national dealers. Looks like they have gone up quite a bit.

If you don't need that flexibility in both circuits then a C21 Contactor Module will do. Contractors have relay only function in both circuits. These are a little cheaper.
That's good advice there Mark, EXCEPT the OP stated they has a CD80 AE rack, NOT a c21. Johnson and Strand may make a C21 retrofit control card for the 1992 AE rack, but that doesn't change the fact that the rack will only accept Original and AE CD80 dimmer modules.

What a surprise! The link to Strand's site does not work. :(
 
That's good advice there Mark, EXCEPT the OP stated they has a CD80 AE rack, NOT a c21. Johnson and Strand may make a C21 retrofit control card for the 1992 AE rack, but that doesn't change the fact that the rack will only accept Original and AE CD80 dimmer modules.

What a surprise! The link to Strand's site does not work. :(
Strand-ed again. 😒
 
You could go the route we did, before we completely scrapped the dimmer rack. Instead of swapping out modules for relays in the dimmer rack, we just left that as it was and installed a dedicated contactor box (a Zero88 rig switch) along with new wall mounted outlets by the patch panel that were non dimmed, hard switched power. Then we could still use the existing patch to the IWB/wall boxes on the stage and in the auditorium to get power where we wanted it, except it was switched power, not dimmed power.
 
Our lighting layout involves four fly lines wired into two CD80 AE racks with Strand C21 processors. The racks have 48 2.4kW dual dimmer modules on each. The idea is to swap out a circuit on each line so I have power available on a per-line basis.

Hi @Wizard of Flaws - our "Upgrade Program" might be of interest to you - see more here: https://www.vari-lite.com/global/upgrade-program

(For more information on why this is now Vari-Lite and not Strand, see here: https://www.vari-lite.com/global/about/signify )


What a surprise! The link to Strand's site does not work. :(

Strand-ed again. 😒

Hi @derekleffew & @gafftaper - please can you confirm which links do not work, or in what way through this thread we have "Strand-ed" you? Have you tried to contact us and not recievd a response? I'd like to get this sorted for you.
 
Everything Strand is now part of the Vari-Lite brand and you will find all info on the Vari-Lite website. We do dimming systems upgrades to relay systems all the time so this should be simple for you. As for cyc lights, you should look at the Acclaim Cycs, the Aurora's and the Coda's depending on the height of your cyc.

 
I've been asked to come up with a wish list for one of the high school theaters I manage and some new lighting came to mind immediately. I'm looking into getting some LED cyc lights (Spectra Cyc 50s) to replace our current incandescent units, but I'd like to provide power to them using our existing circuits. Our lighting layout involves four fly lines wired into two CD80 AE racks with Strand C21 processors. The racks have 48 2.4kW dual dimmer modules on each. The idea is to swap out a circuit on each line so I have power available on a per-line basis.

My confusion lies in what kind of dimmer module I need to swap out to provide power to these and future LED fixtures. Am I looking for a non-dim module or constant power? What, if any, is the difference between the two? Will something like this work for my purposes? I notice the site also has a similar listing, but with "contactor non-dim/SSR dimmer" swapped. My hunch is that it's a mix of dim/non-dim, and the order just refers to which of the circuits is the non-dim?

I'm also concerned with future-proofing as much as I can. I don't know when the processors were installed on our racks, so I have no idea when to expect them to fail. I'm working on the assumption that I'm running on borrowed time right now, given the age of the school. Will the swapped dimmer module work with something like a Johnson Systems retrofit or will I need to purchase a module specifically for it? If the latter, then are there options that will work for both?

Please let me know if there's anything I can clarify, and especially if I've gone awry in my limited understanding of the hardware involved.
Hi Wizard. The easiest, least expensive way to power your LEDs from the existing circuits is to convert the dimmer modules for those circuits into CONSTANT modules, which involves completely bypassing the SSR(s) in that module with a piece of insulated wire (I use 8 gage) that can handle the current for that given circuit. Of course the LEDs won’t draw nearly as much current as the incandescent loads but I use 8 gage wire JUST IN CASE someone tries to connect an incandescent load again sometime in the future. Several other folks here are correct in that if you convert to CONSTANT modules, you have no control of the AC power to those converted circuits without making a trip to the dimmer rack to flip breakers ON or OFF as needed. Your LEDs will have power when the circuits are ON and you will need to run DMX lines to each LED fixture to control Intensity, Color, etc, etc. If you can afford to go the NON-DIM route for your dimmer modules, you WILL HAVE control of the AC power to those circuits from the lighting desk. NON-DIM modules for CD80 racks are available, but they’re not cheap.
One other advantage to using CONSTANT modules is that even if your C21 rack processor croaks, you will still have power at your electrics and thus can still use any LEDs in your rig.
And finally, if you did go the CONSTANT module route, using the module CIRCUIT BREAKERS as ON-OFF switches does work, but generally isn’t great for the breakers. They’re not designed to be used as “switches”… they are CIRCUIT BREAKERS. I turn them ON and leave them ON (which leaves power ON at the LEDs) but again, you have control of the LEDs being ON or OFF via DMX from your control desk.
 
I'll repeat:

IIRC, @abbyt and @STEVETERRY were two of the most vocal opponents against altering the wiring of a dimmer module.
If you look at a”factory” CONSTANT module, that is exactly how they are constructed. No SSR, no coils, just a short length of wire from the breaker to the output pin (two circuits per module=two lengths of wire, one from each breaker to the corresponding output pin). I never suggested that it should be done by anyone who isn’t experienced or comfortable making the conversion. I’ve done lots of these for CD80 and C21 racks/modules with no problems. Again, look at a “factory” made CONSTANT module. That’s all they are… two breakers and two short wire leads, one from each of the breakers to each corresponding output pin.

I’ll refrain from trying to help from now on.
Bye.
 
If you look at a”factory” CONSTANT module, that is exactly how they are constructed. No SSR, no coils, just a short length of wire from the breaker to the output pin (two circuits per module=two lengths of wire, one from each breaker to the corresponding output pin). I never suggested that it should be done by anyone who isn’t experienced or comfortable making the conversion. I’ve done lots of these for CD80 and C21 racks/modules with no problems. Again, look at a “factory” made CONSTANT module. That’s all they are… two breakers and two short wire leads, one from each of the breakers to each corresponding output pin.

I’ll refrain from trying to help from now on.
Bye.
No good deed goes unpunished.
Toodleoo!
Ron Hebbard
 
If you look at a”factory” CONSTANT module, that is exactly how they are constructed. No SSR, no coils, just a short length of wire from the breaker to the output pin (two circuits per module=two lengths of wire, one from each breaker to the corresponding output pin). I never suggested that it should be done by anyone who isn’t experienced or comfortable making the conversion. I’ve done lots of these for CD80 and C21 racks/modules with no problems. Again, look at a “factory” made CONSTANT module. That’s all they are… two breakers and two short wire leads, one from each of the breakers to each corresponding output pin.

I’ll refrain from trying to help from now on.
Bye.

You have to expect ETC employees to tell you not to modify their equipment. They don't want to take on the liability of telling someone they can do something and then getting sued when someone does it wrong and gets hurt, killed, burns the theater down, etc. Same reason people don't give out rigging advice online. you never know who's going to read it and what terrible things they might do with that information that they didn't fully understand.
 
You have to expect ETC employees to tell you not to modify their equipment. They don't want to take on the liability of telling someone they can do something and then getting sued when someone does it wrong and gets hurt, killed, burns the theater down, etc. Same reason people don't give out rigging advice online. you never know who's going to read it and what terrible things they might do with that information that they didn't fully understand.
Well, I would say any unspecified modification to an electrical panel will void any certification it might have gone through as installed. Racks that use screw-terminal power cubes might be easier to bypass but then anyone down the road might expect it work as it says in a manual.
 

Users who are viewing this thread

Back