Automated Fixtures Dimmer Racks with Moving Lights

[jaamulberry]

So I couldn't find a direct answer to my question and maybe my searches weren't clear so I apologize in advance if this is a repeat question.

We don't have any Edison power in our theatre (not in the clouds). We have a ETC Ion and we are looking at renting some moving lights for a show. Is it possible to put the moving lights on a dimmer and just park the dimmer at full? I know that most moving lights need clean power 24/7 and can't really be on dimmers. Just wondering what the risks are and any quick solutions to this.

Thanks in advance,
Jacob

 

[Les]

Hi Jacob,

No, it is not advisable to do this. There have been many threads on this in the past but we just went through a large forum upgrade, so maybe that has temporarily affected the search engine. Anyway, powering moving lights from a dimmer (even parked at full) can cause all kinds of havoc for the power supply and really any electronics in the unit. Basically, it can burn out all kinds of expensive parts (possibly even catastrophically), which the rental house would probably charge you for. They know the failure modes associated with running on a dimming circuit.

Quick solutions... Well, if you have a Sensor rack, you could look in to renting relay modules. A rental house may have them, or you could purchase them if you've got the budget. The cheapest/dirtiest solution is to run the proper gauge extension from the deck to the electric. Use a proper lighting jumper (12/3 SOOW) and use adapters at the ends.

Otherwise, you'd be looking at renting a distro. Come to think of it, this would be my first choice, but you'll still be running cables from the deck to the pipe.

 

[jaamulberry]

What would be the easiest/most cost effective way of making this work? I have a feeling that a hundred feet of extension cords isn't great either. :/

 

[Les]

Easiest/most cost effective (and one of the safest) would be renting relay modules (CC modules) to put in your rack (assuming you have ETC Sensor racks, or some other popular brand that has these available). Essentially, if your moving lights are hung on Electric 1 and say you want to power them from Dimmer 55 [which happens to be on Electric 1], you remove that corresponding dimmer from the rack and replace it with the relay module. Note that you'd actually be converting two dimmers to relay only, since there are two circuits per module.

This is the type of thing I'm referring to when I mention "relay module". Given the price (and again, assuming you have Sensor racks), a few of these would be a VERY worthwhile purchase.

http://www.fullcompass.com/product/...ign=googleps&gclid=CNaqvbOd2bkCFS1p7AodkyQAow

 

[jaamulberry]

How much would one of those cost to rent/buy? These are the dimmer racks we have I believe. We are in Moorhead MN

http://www.viterbo.edu/academic/ug/education/edu250/dimmers.jpg

 

[Les]

Ah, you have CD80's. That changes things a bit because I'm not sure if Strand has relay modules. If they do, I don't imagine any rental house will have them.

Are you only putting moving lights over the stage? If so, renting the distro may be the best option. There will be some cabling, but it depends on what your placements are.

 

[JChenault]

Im not entirely sure a distribution box is required. It depends on which moving lights you are going to use ( IE what are the power requirements you have) - and what kind of non-dimmed power you have anywhere near where you want to hang them. If the fixtures you want to use are less than 20 amps , and you have some good backstage circuits, you could run extension cords up to the fixtures from the wall outlets.

Now that said - the cable must be adequately sized and of the proper type ( this would be true of a distribution box as well). And you need to be sure you understand what else might be on the breaker.

 

[len]

Running extension cords isn't that bad. Not ideal, but not terrible, either. Plus, you're going to have to run data anyway, so what's one more cable? It appears you can't convert any current dimmers to non-dimmed circuits. Maybe you can have the people you're renting from take a look at the space and get their recommendations, since there's a lot of flow-chart type questions that could be asked.

 

[llburg]

Although a more expensive way to go, and assuming you truly have CD80SV dimmers, and not plain CD80, these are an option I think:
http://www.strandlighting.com/index....Dimmers&srctype=detail&back=products&refno=5

 

[phenry]

Although a more expensive way to go, and assuming you truly have CD80SV dimmers, and not plain CD80, these are an option I think:
http://www.strandlighting.com/index....Dimmers&srctype=detail&back=products&refno=5

From the picture, yes, those are CD80 SV modules, so these replacement modules would certainly work. If a rental house has any would be up to them. Call around and check, and if not, if you are going to be renting movers annually, then perhaps see if buying one from a dealer would work with your budget.

 

[jowens]

Hey Everyone, Great and timely post. My question is almost answered here, but...
I'm looking to get some led pars (see forthcoming post), should I be getting the Sensor RELAY unit or the Constant Current unit for this? (High School stage install, 3-4 shows a year and tons of concerts/events)
I intend on switching out a dimmer from an empty channel on an already-in-service Unison.

Thanks!

Joe

 

[Wood4321]

Hey Everyone, Great and timely post. My question is almost answered here, but...
I'm looking to get some led pars (see forthcoming post), should I be getting the Sensor RELAY unit or the Constant Current unit for this? (High School stage install, 3-4 shows a year and tons of concerts/events)
I intend on switching out a dimmer from an empty channel on an already-in-service Unison.

Thanks!

Joe

I would suggest a Constant Current module is the way to go. Then you don't have to worry about it being accidentally turned off. They are also usually less expensive than the relay modules.
In any case, if you end up using relay modules, Make sure they are Air gap relays, not a Solid State Relay. Some of the older Strand Non-dims use SSR's and will still result in a modified waveform that is bad for switching power supplies.

 

[sk8rsdad]

If the rack is accessible and visiting it is a regular part of your startup/shutdown activities then a constant current module is fine. Otherwise, a relay may be a better choice. My venue uses relays and "parks" them in the console. It takes several keystrokes to "unpark" a parked channel so turning them off requires deliberate effort.

 

[MNicolai]

For LED's, it doesn't matter so much.

For arc-source movers, it can matter quite a bit. Relays allow you to power down the fixtures when you're not using them so the fans don't suck in excess dust after-hours, but if you should accidentally switch the relay off (DMX disturbances, exiting the show file in the console, temporary loss of power at the console), now your movers will shut off and need to take the time to restrike. Depending on the mover, this can take a couple minutes or a good number of minutes. You can curb some of these potential headaches by firing the relays via an architectural lighting controller instead of from the lighting console.

Downside of constants is that unless you kill power at the rack or each light, fans in the lights will continue to suck in excess dust.

Again though, LED's tend to be just fine to leave on 24/7, so if LED's are all you'd be using the for, constants work fine.

 

[cbrandt]

Every benefit you get from shutting down a moving light, you get the same for shutting down an LED (except having to restrike). All those components inside the LED will last a lot longer if they shut down when not in use. Most LEDs have fans in them, some are smart enough to cycle off when they aren't hot, but many will run as long as the fixture has power. It won't hurt it if you leave it on overnight every once in a while, but it is a really good habit to turn it off when not in use.

My 2 cents, find a way that is convenient for you to have access.

 

[JD]

Let me just throw two more cents in-
You probably all know this, but in case someone drops by this thread I think this needs clarification:
There is a big difference between a "Relay Module" and "Relay Mode."
Some dimmers support "Relay Mode." In this the circuit is either 100% on or totally off. Unfortunately, the 100% isn't really 100% and there is a pretty nasty waveform at the front end. These are basically dimmers, just being run differently.
A "Relay Module" is something that fits in the rack to replace a dimmer module. These usually contain actual mechanical relays and when they are closed the output power is no different then what you would have coming from a breaker on a distro unit. These are what you want to run Movers and LEDs off of.

 

[JohnD]

This seems a good time to ask if anyone has any experience yet with the ECT Sensor ThruPower modules? For those not familiar with it, it is a dual 20amp dimmer module WITH built in mechanical relays so either side can be switched to constant power.

 

[MNicolai]

This seems a good time to ask if anyone has any experience yet with the ECT Sensor ThruPower modules? For those not familiar with it, it is a dual 20amp dimmer module WITH built in mechanical relays so either side can be switched to constant power.

I know of a couple installs that have them. Can't say I've heard anything one way or the other about them as far as user experiences, but this little diddy from the data sheet should cover all the bases pretty sufficiently:

Where your moving lights, LED, scroller, or power supplies warranty depends on constant power

 

[derekleffew]

Sorry everyone for the hijack...

...
but this little diddy from the data sheet should cover all the bases pretty sufficiently:

Where your moving lights, LED, scroller, or power supplies warranty depends on constant power

Ditty. (And as long as I have my English teacher hat on...)
"your moving lights, LED, scroller, or power supplies warranty depends "
when you can't decide, or don't know, the difference between plural and possessive, just omit those pesky apostrophes. Pay no attention to subject-verb agreement. Mix and match at will.

I hope the power module is better constructed than the sentence describing it.

 

[hobbsies]

This seems a good time to ask if anyone has any experience yet with the ECT Sensor ThruPower modules? For those not familiar with it, it is a dual 20amp dimmer module WITH built in mechanical relays so either side can be switched to constant power.

There was an interesting discussion about those here a few months ago from a dude at design lab in Chicago asking for CBs opinion on them...http://www.controlbooth.com/threads/etc-thrupower-system-design.30290/ ok I guess it was a year ago. Crap, time flies...