Cinematography Mailing List - CML

Dimmer Boards and Control

20th May 2007

Asking a bit of a refresher question, since I never did any dimmer board stuff when I was a best boy, I thought I would ask.

Now I just wanted to know what is the most common set up for dimmer board control. In other words, what do you normally order. I know you need the board, DMX cables, remote distro box for all your 20 amp's, socapex stuff, am I missing anything here?

Also, what happens if you have more than (24) 20amp circuits? Do they make bigger boards, do you get two boards. What problems are there to watch for, etc. And anything else you can think of.

I have done a few gigs as a gaffer, where we used dimmer boards but didn't get too involved in the distro side of things, so I thought I would ask. Don't really want to ask my "way too busy" best.

Maurice Jordan

>>Now I just wanted to know what is the most common set up for >>dimmer board control. In other words, what do you normally order.

Hi Maurice

You ask about dimmer board control, do you mean power distribution for the dimmer pack/racks or the control board. It sounds like you know you need the control board, so I will assume you mean the distro for the racks.

Dimmer racks come in various sizes--24 2.4Kw, 48 2.4Kw, 96 2.4Kw, and then there are 60A dimmers and 100A dimmers, as well as 100 Amp 240V dimmers for 20Kw/24Kw. If you are running a 48 channel 2.4Kw dimmer rack--at full capacity you would be drawing 960 Amps--so a typical 1200Amp three phase run of 4/0 with Cam-Lok should do the trick. Keep in mind some racks have both reversed neutrals as well as ground, and some racks have the capability of double neutrals which come in handy if you will be doing any ques that will get your load out of balance.

If you are running multiple packs alot of times an opti-splitter is a good idea to have, as this will make sure each of your packs is getting a good clean DMX signal. Obviously larger rack systems will require more elaborate distro systems, and sometimes you can put multiple racks on one service if you know you wont be maxing out the power supply due to low loads such as dimmers running practicals, or smaller loads than their capacity. It may be a good idea to coordinate all of this with your very busy best boy--he might actually thank you for taking the time, and ordering all the right equipment the first time thru!

All the best!

Mike Ambrose
LA Based

Don't forget, if you're using more than one dimmer pack, to get the jumpers so you can hook them into your power.

And the small DMX cables to daisy-chain the packs together.

And yes, they make bigger boards than 24 channel. Many boards are 96.

Harry Box's book on lighting has a really good overview of this stuff.

Phil Badger
gaffer, LA

Here we go . . .

Adequate size feeder for total anticipated load, not total capacity of dimmers.

Camlok tee;s to break out power for each rack.

Short DMX jumpers to daisy chain control signal. Long enough DMX to get from first rack to control position.

2.4k Racks are available in touring packages in 12X, 24X, 48X, and 96X

Usually, but not always they will have ports for plugging 6 ct. socapex directly into the rack without male break outs.

Order 6 ct soco's in whatever lengths you need. Usually 150' is the longest available, or that you want to carry. Order 1 female breakout, for each 6 circuits your using , not every piece of cable. You'll need to come up with a numbering scheme for the cables to plug to the rack, usually a letter followed by the circuit number on the breakout, i.e. Multi A1-6 plug to port A which is dimmer 1-6, Multi B1-6 become dimmers 7-12 etc. Get a couple of spare breakouts as well

Usually breakouts are 2P&G unless otherwise spec'ed. Order adapters to plug heads if necessary.

Consoles - Given your newbie status I would suggest trying to get an ETC Express 48/96. As well as having the ability to record and playback cues, it has 96 manual faders that can be used to control 96 channels in single scene mode or 48 channels in 2 scene mode. It will save you the necessity of having to learn to used the "computer" side of the board. If you have more than 96 simmers, you will have to "soft patch" multiple dimmers to each channel to control them all, I.e. dimmers 1&2 controlled by ch 1. Easy unless you don't know how to do it.

Higher end consoles, which you probably don't need include ETC Expression 3, or express 250.

All that bewing said, I really suggest you hire a dimmer guy who already knows this stuff, especially console operation.

Bill Berner
IA 600 DP

Thanks for the input guys and gals ( A few people called me too).

I haven't whipped out the Harry Box in a while but I will take a gander.

A good portion of this stuff I knew and some I didn't. I haven't been around dimmer boards since I lived in NYC (about 6 years ago) and even then, my hands on was minimal. All your info has made the dimmer board picture clearer for me... I will be letting my best deal with the most technical parts of all this, I just wanted to make sure I know, what I know and the pick up the rest that I don't.

Thanks again.

Maurice Jordan

Bill Berner wrote :

>>I would suggest trying to get an ETC Express 48/96.

That's a great board. Make sure you get the manual and you can very quickly figure out how to do submasters and that sort of thing. It can be a great deal of fun.

Sometimes when you order the packs you get a mix of the socopex ins and the bates. Make sure you know what you're getting, or make sure you go ahead and order the breakins and breakouts to cover yourself. You can always send them back -- much quicker than waiting for them to show up if you don't get them in the first place. Make sure you get enough female Edison to male bates adapters. They also make the Edison breakins, but if you get those remember you can have lights that already have bates (like Leikos and parcans), so make sure you get female bates to male Edison adapters just in case. Also it's good to order a spare CD80 pack since sometimes they can have some problems.

Also it's important to make sure you're either single phase or three-phase, because the packs can be switched from one to the other.

The last job I did like this we were stuck using single phase power at Universal and the rental company switched them all over ahead of time, which was nice.

Phil Badger
gaffer LA

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