Adding a Circuit to a Distro Box....


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Note I WILL NOT BE DOING THIS UNSUPERVISED, This is just for my own knowledge and curiosity.

How would you go about adding a circuit. Lets take a Regular Distro Box with a few empty spaces. If i wanted to wire in a Dimmer rack. How would i do this? I know i need feeder cable with Cam-Loks to go into the dimmer...but how do you wire it into the distro-box to draw power

again i will not be doign this it is only out of curiosity
That'd be my vote, too. If you want to run the wire from one place to the other, a lot of electricians are fine with that, just having them do the final connects. But let a pro do it.

it isn't that hard

From my understanding of distribution box's they are just basically a circuit panel that is portable. Know that you would do it the same way you would add a circuit to a panel. You would have to ensure you are buying the proper size of breaker [physically and electrically]. If you know how to add a circuit I would assume you could do this. When all else fails google it.
There's a lot of issues that can't be explained in a short internet post. A sound guy and I had this very discussion earlier this week. There's single phase, 3 phase, and high legs, and this and that, and a whole lot of variables, most of which I already can't remember. If you don't know how to do it, find an electrician who does. If the panal is live, you don't want to make a mistake. If it's a distro, you can make a mistake and it won't kill you. Until you give it power. Then it could kill you. So don't screw around. Get an electrician.
“Note I WILL NOT BE DOING THIS UNSUPERVISED, This is just for my own knowledge and curiosity.

How would you go about adding a circuit. Lets take a Regular Distro Box with a few empty spaces. If i wanted to wire in a Dimmer rack. How would i do this? I know i need feeder cable with Cam-Loks to go into the dimmer...but how do you wire it into the distro-box to draw power

again i will not be doign this it is only out of curiosity” - JP12687

Given his notes and that he is curious, I will answer as best I understand to this point and expect more refinement in further help. If Ron and others with experience, much less that licence are still active perhaps they will also chime in in a general educational way once the subject is further refined.

Just out of curiosity, and as someone that does this type of thing for a living in responding, again, if you have not been trained in such things, don’t attempt it. Large difference between someone on line you don’t know saying how he would and how you should do things. Much less the company I work for in ensuring my work has a million dollars in general liability in addition to no doubt more for stuff we create. Hack work can and is often very dangerous even for the experts. At the moment a major company for this type of thing is two at a time taking back all over 16 of our $1.6K AC Distros due to electrical engineer specification mistakes I have helped to refine given problems with 400A three phase AC-Distros have been blowing up in recent years on some very major high profile rock tours. Sometimes even a electrical engineer in designing a system can forget something as simple as a lock washer or ferrules in preventing screws from coming loose, but such things can cause a rack to go up in a puff of smoke. My warranty refinements are based on what’s seeming to go wrong but I am not a electrical engineer in designing and certifying such things for use. Just adding a three phase 30 amp circuit to above racks involved asking the engineers what’s best - a tap off the lug or off the main given a already balanced load? It’s not just a electrician, it’s a electrical engineer with even larger liability than my company has that is doing the design concept work on such things.

(By the way, watching Blue Screen TV with Richard Simmons at the moment, most of you won’t remember his TV show many years ago, but this guy has the timing that could throw off any show.) Ok, scene over. Wait a minute, not over yet.... Ok, Richard Simmons has officially stolen the show.

I think you are confused in terms and concept at the moment. This could be a problem requiring more refinement by you. First you mention a AC distro box but refer it more in a way of distribution panel somewhere in the theater in adding more circuits to it after the dimmer. Or is it a AC Distro unit with empty space you also want to add a set of dimmers to? Very different things as those above in responding have noted sort of. Above this is the other, third option of a sub or main panel for power coming into your theater with empty slots potentially used to powering up more dimmers. A third question thus in different subjects. Speaking as one that has melted down a dual phase 100 amp breaker, empty slots don’t mean you have more power, much less you still have to balance the load.

It most seems like a question of powering up more dimmers from a house service panel with empty breaker slots than a remote service panel (AD-Distro) or adding dimmers to a empty slot in a AC-Distro. Given this service panel with empty slots - others will possibly tap into, in powering up more dimmers, it’s mostly a question of the panel in it’s supply amperage and phasing available and load than empty breaker panel slots. Just because you have an outlet not plugged into does not mean you have more power available. Ignore the CamLoc for the moment. It’s a name brand like Leko is to Strand as a brand in describing a trade name for a specific piece of equipment but in general not useful at the moment. Describe what it is that you would intend to power up from, it’s potential and load. A licenced electrician can determine this but in general any stage hand in describing his system should know the basics of. Perhaps a 200A three phase panel? Empty slots, what do you have already powered up by it? Say a 96way 20 amp dimmer system? This given three phases would already equal 640 amps per leg of power that’s dependant upon not all of the circuits being on at the same time or you would blow the main breaker easily. In fact, no more than 1/3 could be on for more than moments in supply power. Adding to such a system that no doubt is not a fact of where you are would be out of the question. But given even a 600A system, it’s a question for a licenced electrician and his liability coverage that he pays for given the licence and training to determine available or safe power for. Certainly there is lots of systems where you can’t go above 50% on all circuits available and they are as in use and control somewhat safe, but still what happens if the errant director wanders up to the booth and decides they need more light? What happens if the breakers get old and don’t trip, just melt down in a spectacular way? Adding more dimmers is not always an option even if there is more breaker slots to plug in another dimmer to. This is something again for a electrician to determine according to the National Electrical code - they base their licence upon understanding, and something in advising it’s possible, they stake their liability insurance upon saying you can do it.

So how do you do it? You add a breaker sufficient to cover the load, punch a knockout and add either a sub panel or switch panel for the dimmer or if the case of a temporary loading on the tap - 60 days maximum, wire your CamLocs directly to the panel breakers. Must have either an outlet panel for disconnect or tails no more than arms reach from the loading. Lots of ways to wire up a dimmer pack. Some are done temporarily, others are permanent install. Don’t confuse the necessities of either. In the case of tails’, as mentioned for anything over a 60 amp loading, you are allowed and wise to do separate connectors for each phase of power. CamLoc style is entertainment and even in some cases welding standard way of doing this. There is also multi-pole large plugs on the market for over 60 amp loads which can also be done. In addition to this, since it’s no doubt a permanent install, conduit of some type in covering the wires directly wired to the breaker panel can also be considered a means of power and disconnect if within arms or 10' reach. In other words, CamLoc while necessary for a temporary access to power on loads above 60A, is normal above very expensive pin and sleeve alternatives, it might not be necessary for a permanent install. It also might not be necessary for temporary loading where a cut-off switch/sub panel is available to kill power to that individual circuit as long as the temporary loading is of listed type of cabling equipment for a temporary loading. In other words, there is lots of ways to skin a cat. Still it’s a question of what you have and intend.

In the end, that’s about some of the factors in doing so. How do you do so is not something I can state here or off line in ensuring you don’t kill yourself in installing such a thing as you ensure you would not attempt anyway. Sort of like doing the mythical hot tie in. Yes it’s done, but of those qualified to do so of which I count myself, you won’t find anyone available to other than instruct you in person.
Thank you, I have always been curious about that. For some of my shows we have to Rent Dimmers but the city electrician always comes when i am in class so i can never observe him doign the install. I've looked at it and understand the basics, but was just wondering "why" i like to learn as much as possible, yet i do know not to try things without being supervised and trained MANY times before doing it on my own.

More specifics about my theatre. My dimmer room has 3 Different Panels and one Main Shut off for all 3. one panel controls our 96x1.2kw Dimmer Rack; another panel controls stage outlets, work lights, has abou 10 empty slots. and the 3rd controls Emergency House Lighting, Aisle Lighting, and office outlets.

Each of the 3 boxes say 200amps on them. And each besides the 96x1.2kw have seem to not be using anywhere close to the max. power. But again i could very easily Be wrong. Even the 96x1.2kw panel has 4 openings on it.

So i guess the question would be how to under those situations set up the ETC Sensor Rack that the electrician always installs.

I wish i could just watch him one day...maybe for the next show.
First guess he is tapping off the house work light/receptacle power, second guess is off the emergency light power though that's no doubt poweering the sound system given it's not coming from a seperate transformer.

So in any case in assuming the "sub panel" that powers you dimmer packs is maxed out for power available to tap into, the electricians when you are gone are tapping one of the other sub panels off the main to temporarially power up the extra dimmers. This relies upon the concept that there is extra capactiy available to one of them say the house work like panel during shows. It's than as you theorize only a question of installing a breaker into the empty slots and wiring off it by way of Cam Locs into the rented dimmer pack it would seem. Simple enough as long as the sub panel can handle the load and the main where all three panels are drawing power from can than handle the combined loading. This would be a electrician question in not only installing cable but calculating maximum safe loading.

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