Building your own lighting board

falcon

Active Member
We commonly do fashion shows in my schools cafeteria and we have to bring in stage lights. We usually have 4 6" fresnels and 2 36 degree strand sls (i think thats the strand light) and we convert their twistlock plug into standard edison and leave them plugged in for the enitre show. Afterwards, we have to scramble to unplug them all and some of the outlets are difficult to reach to let them cool down before we can derig everything for the night.

My TD was thinking about building a lighting board with standard wallmount household dimmers to plug the lights into and then into the 40 amp drop box. Does anyone know a SAFE way to go about doing this. We both have electrical experience so between us we can wiring just about anything properly, but what are the dangers that would go with this project and how to prevent such dangers and all those liabillity issues and so forth.
 
I really dont think there is a safe way of doing this. most household dimmers will not handle more than 600w load, so are by no means good enough. also, household dimmers, or any control equipment for that matter (from Home Depot) will not be rated for theatrical use. You would be much safer just buying an inexpensive lighting board. You will save in the long run.
 
i've already read the post, thats waht remined me of what my TD wanted to do.
If we go with an inexpensive lighting board, we would have to buy portable dimmers. If we go that route we might as well just get the dimmers and use our own board, but their is no place to plug the dimmer pack in. Sure there is a 40 amp drop box but that is above a ledge, difficult to get to and doesn't match any plugs i've seen on portable dimmers. this is a really weird drop box, it has 5 prongs and its a twistlock type deal. but we do have a plug in it that goes to regular edison, 20 amp edison and one more type which i can't figure out what it is. I ahve to look when i'm alone in teh caf again.

We just need something to run the 6 six without having to buy anything that is too expensive. As it stands right now, our production this year is the only one in the last 4 years that turned a profit.
 
There are dimmers made by leviton that can handle over 600w. Most of the fresnels and lekos at my h/s were 500w.
 
I don't think it's worth the risk of something bad happening. It wouldn't cost that much to get a couple of small dimmer packs, and a little dj light board.
 
5 prong twist lock looking receptacle is not something you want to plug your gear into. Given your description, I'm inclined to believe this is a tie in for all three phases of a wye plus ground (got a straight pin in the center?). 208V between the hots, 120V between a hot and the neutral. Might also be 480V between the hot legs and 277V between a hot leg and the neutral. Your gear will not like this.

The panel will be marked in the notation 208Y/120 3Ø or 480Y/277 3Ø assuming this is the case.
 
Do you guys not have 4 PAK dimmers out there?

I have a few of them that I use on smaller shows. Keep in mind that the link is for the Jands ones which are 240V 10A, which is 2400W. The new ones (as per the link) has it has sound to light chases as well as the standard pre-programmed chase.

I know Geni also make something similar but in a rack mount version. Has 4x10 program modes (std dimmer, hold on sound, sound to light, chase). Also 2400W.

For small shows or for portability these are value for money. I use them a lot for outdoor feature lighting (trees, walls etc).
 
Given a drop box in adiquate power and a wish not to do remote dimmers, there are many light board/dimmer boards on the market such as those by Dove Systems that are inexpensive and include both light board and dimmers in one light board. Given you specify what form of power you have available the board can either be configured for this or the lighting supplier can recommend another course of action in plugging into it. Probably some form of AC distro or portable sub panel that is possible for you to construct potentially.

I say potentially in that it must comply with all rules about both sub panels and portable/temporary distribution equipment. Lots of little rules to follow but overall such equipment given supervision and experience is not difficult.

Another option might be something I'm also fairly certain is on the market and that's a professionally made single or up to four pack plug in dimmer or switch which has both control and outlet at the place it's plugged in. This way at least instead of hot patching the fixtures into wall outlets which is really bad all around for fixture, plug and outlet, you will at very least with even a in-line switch be able to shut off the current draw before un-plugging.

Still the most cost effective given a power drop of one form or another would be some form of the above Dove board, or even in having a remote light board just plugging the dimmers into that drop of power and sending signal to the dimmers by way of control signal.

Taken as a given you have experience and training in wiring stuff, part of that is also in doing what is acceptable by code.

Now given I have made some architectural wall switch remote in-line dimmers and they get used professionally. Such gear is made to the best quality possible to the extent of even being in weatherproof boxes with weather proof covers at times to protect them from all forms of abuse. Much less otherwise such components will have internal fuse or breaker protection on it as a complete wiring device. The training specific to these items in making such gear over the years is a bit different from in general knowing how to wire it. My recommendation would be in ensuring both compliance and listed or engineered equipment to be used by your theater, that should even line dimmers be necessary, buy them constructed for you rather than making them. At very least buy one and study than with supervision you have, make more to the exact same component standards. Them little details are often large differences between what's electrically safe and what will not be safe once dropped a few dozen times and dragged around the stage.
 
There are a few commercial grade boards that are along the same lines as the build-it-yourself type described here. Dove made one that had 12 channels and plugged into two 20a 120v circuits. If they were 500w fixtures there would be plenty of capacity. You would know that all the internal wiring, bussbars, etc. would be up to the task, and wouldn't need any dimmer packs.
 

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