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[Hank Staples]

I have recently aquired 3 Lightronics RM-121 rackmount dimmer packs, 4-10' spans of single hung Penn trussing with 8 short par 64's per bar in the truss (32 total ), and all the socapex cabling etc from a local church. I am aiming to use this on some bigger gigs. Since I am a total noob when it comes to lighting I need to know the best way to plug in the dimmers. According to the manual these draw 60 amps and will need to be wired
as follows
"Each RM-121 requires SINGLE PHASE 240 VOLT AC or TWO PHASES OF A THREE PHASE 208 VOLT AC
service. The neutral conductor is shared by two hots so it is important that the two hots used are of different phases.
EACH PHASE must be capable of providing 60 AMPS" via the manual 

As little as I know about lighting I know less about the electrical aspects other than calling the local electrician at venues to wire in my distro. what is the easiest way to integrate these (read..plug in)so I can use the dimmers ? 

[James Feenstra]

I have recently aquired 3 Lightronics RM-121 rackmount dimmer packs, 4-10' spans of single hung Penn trussing with 8 short par 64's per bar in the truss (32 total ), and all the socapex cabling etc from a local church. I am aiming to use this on some bigger gigs. Since I am a total noob when it comes to lighting I need to know the best way to plug in the dimmers. According to the manual these draw 60 amps and will need to be wired
as follows
"Each RM-121 requires SINGLE PHASE 240 VOLT AC or TWO PHASES OF A THREE PHASE 208 VOLT AC
service. The neutral conductor is shared by two hots so it is important that the two hots used are of different phases.
EACH PHASE must be capable of providing 60 AMPS" via the manual 

As little as I know about lighting I know less about the electrical aspects other than calling the local electrician at venues to wire in my distro. what is the easiest way to integrate these (read..plug in)so I can use the dimmers ? 

first of all, get an electrician that's familiar with entertainment power distribution (say, someone ETCP certified with a master electricians ticket from your area) to build your dimmer rack for you!! That way it will pass whatever the electrical codes state in your area.

that being said, you basically want to divide up the 6 hot lines (3 dimmers, 2 hots each) between your 3 phases...something like this would work;

Ground; all dimmers
Neutral; all dimmers
Black; Dimmers 1+3
Blue; Dimmers 2+3
Red; Dimmers 1+2

In that configuration using any number of the dimmers in the rack will leave you with 208v and a relatively balanced load across all the phases.

Like I said though HIRE AN ELECTRICIAN!!!

[Hank Staples]

first of all, get an electrician that's familiar with entertainment power distribution (say, someone ETCP certified with a master electricians ticket from your area) to build your dimmer rack for you!! That way it will pass whatever the electrical codes state in your area.

that being said, you basically want to divide up the 6 hot lines (3 dimmers, 2 hots each) between your 3 phases...something like this would work;

Ground; all dimmers
Neutral; all dimmers
Black; Dimmers 1+3
Blue; Dimmers 2+3
Red; Dimmers 1+2

In that configuration using any number of the dimmers in the rack will leave you with 208v and a relatively balanced load across all the phases.

Like I said though HIRE AN ELECTRICIAN!!!

Oh I agree..this is not something I will be jakelegging  . Just trying to wrap my head around how to best get from the distro to the rack where I will be putting the dimmers. Is there a socket/plug rated for the 60watts/208v?

[James Feenstra]

Oh I agree..this is not something I will be jakelegging  . Just trying to wrap my head around how to best get from the distro to the rack where I will be putting the dimmers. Is there a socket/plug rated for the 60watts/208v?

I assume you mean 60 amps...as 60w is equivalent to your average household light bulb

your *best* bet is to have camlock inputs on the dimmer rack that feed all three dimmers straight off the cams

as for 60a connectors, there are several, although like I said you're better off feeding the whole rack camlock and you're potentially drawing 360amps off those three dimmers (if I read the manual right...60a/phase, single phase dimmers...3 dimmers x 60amps/phase x 2 phases each)...you're looking at a 2/0 3 phase connection to run all three dimmers off one supply, or three 4 gauge single phase supplies, one to each individual dimmer.

I've seen very few dimmer racks that have anything except camlock inputs, although you could also use ceeform or twist lock connections provided they're rated for enough amperage. Cams are still your best bet though as they're very unlikely to come out unless someone puts some effort into it.

[Hank Staples]

James...yes 60a That's what I meant. Like I said .."total noob"! lol  After I posted I figued you were talking about direct camlock in..although I have not "done up" a rack with power before..just used a distro and fed off it to my amp racks. That looks like the easiest way to go for sure.

 

I assume you mean 60 amps...as 60w is equivalent to your average household light bulb

your *best* bet is to have camlock inputs on the dimmer rack that feed all three dimmers straight off the cams

as for 60a connectors, there are several, although like I said you're better off feeding the whole rack camlock and you're potentially drawing 360amps off those three dimmers (if I read the manual right...60a/phase, single phase dimmers...3 dimmers x 60amps/phase x 2 phases each)...you're looking at a 2/0 3 phase connection to run all three dimmers off one supply, or three 4 gauge single phase supplies, one to each individual dimmer.

I've seen very few dimmer racks that have anything except camlock inputs, although you could also use ceeform or twist lock connections provided they're rated for enough amperage. Cams are still your best bet though as they're very unlikely to come out unless someone puts some effort into it.

[James Feenstra]

James...yes 60a That's what I meant. Like I said .."total noob"! lol  After I posted I figued you were talking about direct camlock in..although I have not "done up" a rack with power before..just used a distro and fed off it to my amp racks. That looks like the easiest way to go for sure.

for amp racks with a relatively low power draw that makes sense

for a dimmer rack running 100a+, camlocks are the way to go

[Tim Weaver]

Just because your amps are capable of pulling 60 amps per leg from the mains supply doesn't mean that they always will. Your supply side doesn't have to be that beefy if you realize what your total draw is. You have 32 par cans that you will be running off of this dimmer, right? Lets assume that they are 1000 watt lamps. What does that tell us? 32,000 watts / 120 volts = 266.6 amps when running it full on. That is 100 amps less than the total capacity of the dimmer rack.

So as long as your disconnect or gennie is of a proper size and the feeder is big enough to support around 300 amps you'll be fine. If you use 500 watt lamps you can cut this in half, but 500 watters may not get the job done if you have a large trim height, or are outdoors at sunset.


Everything is relative.....

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