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20A power strip (newbie question)


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#1 Anton Delfino

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Posted 28 March 2014 - 01:08 PM

Apologies for the super n00b juicing question. Our office has a small studio space with with 2 20A circuits with Edison outlets spread throughout. I've flipped the breaker a couple of times and it's an ordeal to get the building maintenance guys to come out, locate the breaker and flip it. 

 

Can anyone confirm that setting up a 20A power strip (like this) between the wall outlets and the lights would avoid 

flipping the building's breaker if overloaded? 

 

Thanks!

 

 


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#2 Don Bachmeier

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Posted 31 March 2014 - 07:47 AM

Chances are that the room's '20 amp' circuits are actually more like 15 amp breakers so they would trip before a 20 amp breaker on an outlet strip. Watts/voltage-amps. 


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#3 Anton Delfino

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Posted 31 March 2014 - 12:02 PM

Thanks for the reply, Don. The last time it flipped, I was in the breaker room with the maintenance guy and saw that it was labeled with a "20". It looked like there was a bar that connected both switches, so you couldn't flip one without the other.


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#4 Edward Lawrence Conley III

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Posted 04 April 2014 - 10:45 AM

You would be better off using a 15amp Power strip. The 20A power strip you linked to might not trip before the office CB.

 

What all do you have running off the wall receptacles?


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#5 Anton Delfino

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Posted 04 April 2014 - 01:49 PM

We have mostly tungsten units - (2) 1K soft boxes, (1) 1K fresnel, (2) 650w fresnels, (1) 750w Rifalite (2) 300w fresnels - and a couple of Divalite 400s.

 

We do have a small chroma green cyc one one side of our studio, so our usual set up is the soft boxes lighting up the green screen, the Divas for key/fill, and a combination of 300s or 650 as a rim/kicker. There are no issues with power for these set ups. We start running into trouble when we want to go for a different look and start throwing up the smaller units to do different things. 

 

We do have some budget to build out our studio, so I was thinking that some low cost fluorescents for the green screen would save us from using both 1K soft boxes. 


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#6 Mark Dunn

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Posted 04 April 2014 - 02:04 PM

Unless I've got this wrong, you can only run about 2.2kW off each 20A circuit at 110V. You list nearly 6 kW of lighting.

Watts= volts x amps.

So you are just getting by with your cyc setup if the 1Ks are on different circuits. I'd say you need to find more circuits to spread the load. I'm not in the US so I don't know what you have, but domestic installations here have a 30A circuit for electric cookers (220V) - you must have something similar, the equivalent would presumably be 60A. But that's a job for a sparks.

That extension lead is just that- it doesn't make any difference to the load.


Edited by Mark Dunn, 04 April 2014 - 02:06 PM.

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#7 Anton Delfino

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Posted 04 April 2014 - 02:26 PM

Yes, Mark, you're right. I forgot to mention that there is another circuit in the room as well - at least 15A. I'm doing my best to spread the load, but I feel like I'm walking on a tightrope each time. 

 

Maybe going the fluorescent route to light the green cyc is the best way after all. Thoughts?


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#8 Toby Orzano

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Posted 04 April 2014 - 07:32 PM

I guess it depends on what type of work you do and what you project for the future but if you foresee sticking around for a while and want to allow room to grow, perhaps consult with the building management about getting an electrician to put a camlock drop in your studio. Then you could split off and run a few lunchboxes/woodheads wherever you want them. You'll have plenty of overhead as far as amperage and total security about how much is on each circuit, plus reliable breakers at your fingertips. That would also give you freedom to use large lights that draw more than 20A, if you ever need to.

 

Honestly I have no idea how much that would cost. Switching to fluorescents would also be a decent-sized investment, but I think that would eventually limit you if you were doing bigger shoots. If you're doing well now and want room to expand in the current space, I think getting more power and proper distro is the way to go.


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#9 Guy Holt

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Posted 04 April 2014 - 09:03 PM

perhaps consult with the building management about getting an electrician to put a camlock drop in your studio. Then you could split off and run a few lunchboxes/woodheads wherever you want them. You'll have plenty of overhead as far as amperage and total security about how much is on each circuit, plus reliable breakers at your fingertips. That would also give you freedom to use large lights that draw more than 20A, if you ever need to.

 

Now a days you don't need to put a camlok drop in your studio to have everything Toby mentions above. Like the loft pictured here where we shot a Bose spot, most commercial spaces have plenty of power, you just need to be able to access it. The first step is to determine the maximum  your  electrical service has to offer.  To determine this look at the main breaker of the service head (main electrical panel.) Commercial wiring is almost always three phase, meaning it has three hot legs that are 120 degree out of phase. 

 

 

Transformer-Distro_Sam2.jpg

 

4k & 1.2ks HMI Pars  powered from 30A/240V dryer outlet through step-down transformer/distro for Bose still shoot.

 

A small space would have either 100 or 150A Amps per leg, which means that there would be either 300 or 450 Amps available. While that’s a good amount of power, it is nearly impossible to access it all. The problem is that you can only use the small 120V branch circuits of 15 or 20 Amps. For this reason, you end up not being able to utilize large lights or even a lot of the power that is available at 208V.

 

One way to utilize larger lights, or more of the available power, is to step-down the available 208V power to 120V with a transformer. Most commercial spaces have 208V circuits for motors, machinery, compressors, electric ranges, electric dryers, and special receptacles installed for Window Air Conditioners. Like it does with the enhanced 7500W/240V output of our Honda EU6500is Generator, a step down transformer will convert the 208V volts supplied by these receptacles to 120 volts in a single circuit that is the sum of  two of the phase legs of 30/50 amps each. Now that you have a larger (60A or 100A) 120V circuit, you can operate larger lights, or more smaller lights, than you could otherwise. If you outfit the transformer like the one we manufacture for the Honda EU6500is and EB10000 generators with a bates receptacle you can use standard  film style distro like 60/100A Bates Extensions to run power around your studio - breaking out to 20A circuits wherever you want. By giving you access to more "house power" through common 208V outlets, a Transformer/Distro can eliminate the need for dangerous tie-ins or expensive tow generators (use this link for details.)

 

Guy Holt, Gaffer, ScreenLight & Grip, Lighting & Grip Rental in Boston

 

 



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#10 Edward Lawrence Conley III

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Posted 07 April 2014 - 11:56 AM

Where in Los Angeles are you?


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Metropolis Post

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rebotnix Technologies

Opal

Aerial Filmworks

Glidecam

Technodolly

Gamma Ray Digital Inc

Ritter Battery

CineLab

Rig Wheels Passport

Abel Cine

Wooden Camera

Willys Widgets

Paralinx LLC

Broadcast Solutions Inc

FJS International, LLC

Tai Audio

Media Blackout - Custom Cables and AKS

Visual Products