Dimmer Racks

midgetgreen11

Active Member
So I've mentioned this in threads before about the location of our Dimmer Rack. Its directly Backstage in the SR Wing, and has no door on it. The door was broken off by my predecessors. What does everyone think of this; Where are Dimmer Racks in other people's theatres?
 
Our rack is in our electrical room, which is off the SL wing. Usually students aren't allowed in. Good thing I have access to a key.

I think you should have something covering the rack at least, lest any foreign particles or bodies get in.
 
Yea, what kind of dimmer rack is it? I'm not so concerned with bodies / it is probably safe, but all of the dust and gunk will get inside the dimmers and slow up the ventilation inside it rack eventually tripping the overtemp sensor and temporarily shutting down the rack. Luckily this only happens every once and a while. Unluckily it happens when the rack is being used heavily, such as during a performance.

I would make a cover out of wood with an opening in the front and put HVAC filters someting like this one on the front. This will keep out all then unwanted badness but not restrict airflow any more than the original front door. (all of this is assuming it is something like a CD-80 or Sensor 48pk)
 
If it were at my school I would be much more concerned about bodies-- they tend to find the one way to either shock themselves or mess up the show. On our spring shows where we brought in a ML rig and distro ALL the junior crew wanted to do was play with the distro. Seriously, we had to use large amounts of Gaff and scrap wood to cover up anything that would have bad consequences if a finger were stuck in. Then we finally kicked them out because they pulled off the tape and were messing with it. I don't want to know what the results would be if somebody stuck there finger in a 240V 50A main output...
 
Seriously, we had to use large amounts of Gaff and scrap wood to cover up anything that would have bad consequences if a finger were stuck in. Then we finally kicked them out because they pulled off the tape and were messing with it. I don't want to know what the results would be if somebody stuck there finger in a 240V 50A main output...

Should just lock them in a room with a stack of pennys.... Also, there should NEVER be any way to get in contact with a hot terminal without trying very hard.

If there are open terminals on the unit, there is a much larger issue, if the ventalition door is gone, then either built a new one (I would not go with wood, and dont use just any old filter, it might hinder airlow more then it helps and could lead to more over temps). Otherwise, go without and just blow out the dimmers more often then you usually would.
 
It seems like a huge safety hazard. A few months back a dimmer actually caught fire because kids preparing for the German Club play were screwing with the breakers. They are EDI 2.4k Dimmers. The Maintenance Supervisor keeps telling me he's going to build a cage around it; but never does.
 
In the touring world, you'll find that most dimmer beaches are stage right. Monitor world is usually stage left. I'm told that Willie Nelson prefers monitors stage right. I try to keep dimmers upstage as far as possible. Some people like them downstage. I've also set up dimmers on the wing of the deck downstage of any curtains and exposed to the audience because there was no wing room, or no wings at all. But in rock world, having a cable pick visible to the house isn't such as big deal.

And yes, both sides are always covered except where connections are made. We don't cover unused multi-pin connections. The camlocks have safety covers which are spring loaded. Fortunately, I don't have to worry too much about curious George sticking his fingers in where they don't belong.
 
Last edited:
Hi there,

I have seen dimmer racks USL, SR and SL, in basements and in small shacks (outdoor theatre). The location doesn't really matter, as long as they don't make too much noise and are ventilated properly.

If the location of your dimmer rack is a safety concern, you could ask your boss if you could post a sign on it that says something like, "CAUTION Danger of Electrical Shock" in red. Or put some Caution tape in front of it.

Another thought, if there is a jam for a door since the door has been torn off, why doesn't your maintenance supervisor just put another door on it with a locked knob?

Good luck!
 
In my school, the dimmer racks are in a room halfway up the staircase to the catwalks. Then the racks also have doors on them. However, we have to keep the door to the room open to allow air to continue to circulate and to keep the room from overheating.
However, in order to get to the staircase, you have to have a key so it is pretty safe. (Plus no one ever plays with it unless there is a problem with the dimmers)
 
The hooks that the hinges were supposed to be on are completely ripped off; he's been saying he's going to put a chain-link cage around it.
 
Where I am, the dimmers are in the booth, where it gets very hot. We don't have a dimmer rack, per se, since we have 12 individual boxes that control 6 channels each.

I've also seen them in an electrical room backstage, and in a room just off upstage left.
 
For us the crap-tacular TTI rack we have lives in a room off stage left. It is a room you can only get to through our piano/sound shell storage room. So of course students are NEVER in a room to which they are technically barred access....:rolleyes:
 
At my school we've got the dimmers in a chain-link-style metal cage with a lock - ventilation works fine, and no one's gotten in without permission, as far as I know. We've got the whole setup in a SR sound/light equipment room that we share with some main school HVAC equipment, as well as storing mics, cables, lamps, etc. If you can get the dimmers locked off, that would probably be best, if you have people messing with them - we've never had that problem.

Cheers,
Ilya
 
Somehow you want to put doors on the thing, but if there is enough space to do so, I would put a cage or at least chainlink fencing with a door on it around the racks. You could get one of those chainlink dog kennels to go around it, that way no body could touch the racks unless they have a key or they climb over the fencing and it would be pretty obvious if someone did that!
 
If there is room around the racks and you know you can put a fence or something around the racks, then it would be a good idea. Especially in high school. Find a way to put a door on or something to cover the front and then possibly a cage. Or like I said earlier, just get one of those chainlink dog kennel enclosures that will fit around it.
It all depends on if there is enough room you can spare around the racks. I would be concerned with kids playing with the dimmer racks or trowing trash inside it. (kids do that dont ask me why)
 
I would be careful using any standard HVAC filter because often they quickly become too clogged. Dimmer fans are not as powerfull as HVAC fans and cannot move enough air for propper airflow. Usually the filters used on dimmer racks are designed for electronic equipment and look more like a fine screen than paper. It is also a good idea to clean these filters anually, or more often if in an open space. I try and check filters every month in our racks that are located in the SR midrail gallery. We have old CD80 dimmers (Still mostly working great after 18 years) with "hog hair" style filters. The dimmer manufacturer should be able to provide you information reguarding the propper filter material.
Good luck!
 
I personally think that putting doors between you and the dimmers can be a bad thing, if you trip a circuit mid show, and you can't get to the dimmers, that's bad! I have seen signs that say "Warning, Playing with Amp Levels can cause Sterility" and that stopped most people from touching it. If your kids aren't responsible enough to know that finger+power= bad then they really aren't mature enough to be let in.
Nick
 

Users who are viewing this thread

Back