What wire should I use for DMX + power?

[Steven]

My display this year will include DMX fixtures, starting with the Rainbow Flood Extreme. The RFX, and also those inexpensive 3-channel RGB DMX controllers, expect a 4-conductor cable with ground, +12V, DMX+, and DMX-.

I'm thinking that CAT5 cable works well with DMX and other RS485 networks (like LOR), but those thin 24-gauge wires won't carry the 12v power very far. Instead, I was thinking of 4-conductor 18-gauge speaker cable like this from Monoprice, but I'm a little concerned about the 250kHz DMX signal getting attenuated or getting interference, as the speaker cable may not be twisted pair and my not be the correct impedance.

What are you all using for your DMX+power cables, and how long are they?

[Steven]

Jeff Millard wrote:

I used SPT1.

You ran DMX over SPT1? How long of a run? How many fixtures? Any problems?

[bretk]

I have test run over 100' with the speaker wire you mentioned

[olmsb4d2]

I spoke to the folks at Seasonal Entertainment today about using Cat5 (24AWG) for runs of about 25 feet and they're response was that it was okay.

[aemnky]

In the past I ran my mighty mini's with cat 5e and have had no problem with the 12v. They use XLR cable for DMX and there is no problem with no problem. I'm sure 4 conductor wire will be just fine.

[Ponddude]

Steve don't forget you can use our Blenders to inject the power and DMX data into one cable. A couple of people have contacted me and are modifying those cheap 3 channel controllers to accept the connections from our Blenders. That is always an option as well.

[Steven]

Ponddude wrote:

Steve don't forget you can use our Blenders to inject the power and DMX data into one cable.

I already have a blender on order. My question is about the cable from the blender (DMX+power) to the fixture (RFX). I'd like to put a power supply next to my computer in the garage, and run a single cable from the garage to the DMX fixture(s), about 30 feet.

If I use Cat5, I am concerned about the voltage drop over that distance.

If I use 18-gauge 4-conductor speaker cable, I am concerned about the DMX signal degradation over that distance.

Or should I play it safe and run power and DMX over separate cables?

[Ponddude]

OK I see where your going now...

I will say this. The wiring inside our extension cables is 4 conductor 18 gauge wire. It is stranded as well. The Blender's obviously combine the power and DMX into those 4 cables and send everything through one cable. When we tested the RFX's (which is the first of our products to use this 1 wire setup) we tested one light that was connected to around 600ft of our cables. We experienced no issues at all.

I would never recommend using the cat-5 cabling to apply power to the lights, it just isn't heavy enough duty, but the DMX data can certainly be carried over it. I will say that by splitting up the power and DMX, it basically does away with how the lights were designed to be connected. We wanted to make it as simple as possible and 1 cable certaily seemed like the best way to do it.

Greg

[happylighting25]

Everyone is talking about these 3 channel DMX modules on here. What are they and what do they do? Does anyone have a link of what they are? I am new to these parts and trying to gather as much information as possible to get the lighting projects started!!

Thanks,
David

[Steven]

happylighting25 wrote:

Everyone is talking about these 3 channel DMX modules on here. What are they and what do they do?

Here's a link to HolidayCoro.com.

They currently are selling for $7.99. They seem to be weatherproof. Each has 3 cables: 12v power, DMX input, and RGB output. They will drive up to 2 amps per channel.

[gizmomkr]

I do appreciate the idea of 1 cable for everything, but my experience as an AV tech with long DMX runs and power runs will usually lead to my keeping things seperate for any show.

Chances are combining especially shorter distances, things will be fine.

I have cat-5 coming out my ears, so that covers all my data. for some smaller items I run power over seperate cat-5, sometimes even twisting several pairs together.

This past season, I had some DMX stuff in the yeard that was 12v, I ran cat5 for data, and a seperate 4 conductor 18Awg wire for power.

I have never had issues with random lights, channels whatever turning on, or controller loosing unit ID's... I suspect these are EMI related.

As for the 3 channel controllers - I am guessing most are talking about a 3 channel DMX controller like :http://www.ecolightled.com/product/dmx_driver_rgb_led/dmx_led_drivers for driving some "dumb" led's. Smart and dumb LED's are all the rage now that LOR does DMX for cheap. The old iDMX was too expensive for most, and if you needed 2 or 3.. forget it.

[CLD Kevin]

I asked this very same question last year and was told by zman and dr. jones that I should NOT use standard 4-wire for dmx. DMX needs to be run on 100-120ohm cable. This is the reason why I changed my whole setup as I was originally going to use 18awg 4-wire. Using 18awg 4-wire may not be a problem for 1 single dmx unit that is not far. But if you have multiple devices on the same branch...I don’t have an answer for that. I never got to try it. I assume NO per the posted advice.

For my setup, I had 27 dmx devices all on 1 branch. I ran power and dmx on the same cat5 cable. I inject power every 9th device. Each device was 3 RGB LEDs so power load was very minimum. If I tried this same setup with say several RFX and RGB strips on one DMX branch...I would use cat5 for the dmx signal only and separate cable for the power.


Steven…you chimed in on my post but not about this specific question.

http://forums.lightorama.com/forum75/27001.html

Kevin

[Steven]

Cracker wrote:

Steven…you chimed in on my post but not about this specific question.

http://forums.lightorama.com/forum75/27001.html

That was before I considered using DMX. Now that I read that topic, I see that it answers my question, and that is that I should keep any DMX runs over 18-gauge cable very short.

[happylighting25]

Thank you Steve for the info on the DMX modules. They seem nice but very cheap. That always concerns me.

I know I am new here but I have been doing DMX lighting in college for a few years now. I certainly don't know everything about it however I do know a bunch of things related to it.

I mentioned in some other posts that I have a Rainbow Flood Extreme which was given to me as a gift. I ended up using it in a winter production this year of "The Winter's Tale to light up some back drops. The setup involved connecting the Blender thingy to our in house junction boxes. (we used one of the 3 pin XLRCAT5 adapter from Seasonal Entertainment) From there I ran just 100ft of the cabling from Seasonal Entertainment and connected it to light at the back of the stage for the back drop. It worked flawlessly for the 2 weeks of the production.

Again, I am no expert but even in a complete in house theater setup it worked great.

David

[gizmomkr]

I think like many things there are "Best Practices" and there are Laws of science.

You cant power a 1,000 Watt flood with a 2 conductor 22 Awg wire. If your holding it in your hand, you will get hurt, your an idiott.
LAW OF SCIENCE

Its a good idea to change your oil and rotate your tires every 5,000 miles ( or is it 10,000) Is your car going to explode like the melting wire above ? NO. Is it better for your engine - Yes.
BEST PRACTICE.

Another way I could say it is : Should be fine, best of luck - if strange things happen, you should look at this as a potential cause

Now where is that post from the guy that wanted to run power to his controllers over cat-5

[Dr. Jones]

There is a specific cable that is used in the entertainment industry that does just what you want to do. It is generally called scroller cable or color changer cable. The good cable uses a 22ga twisted pair for data and 14ga for power.

Here is a link - it is the pccct cable - http://www.tmb.com/Pdf/ProplexP-web.pdf

[bretk]

Dr. Jones wrote:

There is a specific cable that is used in the entertainment industry that does just what you want to do. It is generally called scroller cable or color changer cable.  The good cable uses a 22ga twisted pair for data and 14ga for power.

Here is a link - it is the pccct cable - http://www.tmb.com/Pdf/ProplexP-web.pdf

Nice cable but ouch on the price:shock:

[gizmomkr]

Wow.

Color Scrollers- what a blast from the past!

What an AWFULL product. Those things broke more than they worked. Thank god for pixelpars.

[Dr. Jones]

gizmomkr wrote:

Wow.

Color Scrollers- what a blast from the past!

What an AWFULL product. Those things broke more than they worked. Thank god for pixelpars.

you still cannot get the output of a incad with an led. Scrollers will be arround for some time.

Case - a SpectraPar although can change to millions of colors( no one can percieve all of those colors) - point - does and will not have the same lumen output of a 1k par64 at a standard distance

Also - a major manufacture of high output moving lighs still uses scrollers to change color and paterns

[dmoore]

Steven wrote:

My display this year will include DMX fixtures, starting with the Rainbow Flood Extreme. The RFX, and also those inexpensive 3-channel RGB DMX controllers, expect a 4-conductor cable with ground, +12V, DMX+, and DMX-.

I'm thinking that CAT5 cable works well with DMX and other RS485 networks (like LOR), but those thin 24-gauge wires won't carry the 12v power very far. Instead, I was thinking of 4-conductor 18-gauge speaker cable like this from Monoprice, but I'm a little concerned about the 250kHz DMX signal getting attenuated or getting interference, as the speaker cable may not be twisted pair and my not be the correct impedance.

What are you all using for your DMX+power cables, and how long are they?

I have used thousands of feet of CAT5 in my display since 2010 to carry the signal+power. I've carried signal over 90 controller with nearly 200 splice points with power injected every so often without issue. If you generally stay around 3 amps on three pairs of wires, you'll be fine. Of course how far you can go depends on the number of items along the wire and the overall length of the cable.

CAT5, IMHO, is the way to go with RGB. Cheap, easy to hook-up with both signal and power in a single cable, you can get "extension" cords in any color and length.