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lighting advice for high power HMI and theory of three phase electricity


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#1 Shermen L

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Posted 25 July 2014 - 12:13 AM

I’m prepare doing lighting for a indie film, somehow I’m still a beginner in lighting, I used to do lighting with small power light, so I used to drag the household power,.Since I prepare to light a large scene , maybe need  to rent some large power HMI (4K or more)  which the household power  cannot afford, so what options can I have ?

 

I’ve thought of generator, but I’m not sure if the power is steady to operate high power light, also the noise issue.

 

I’ve heard of three phase electricity which most of lighting make use of, but I am not sure the theory and how to calculate the power, is there any advice on that ? Also normally where I can get the three phase electricity?

 

Thanks


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#2 John E Clark

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Posted 25 July 2014 - 12:05 PM

 

I’m prepare doing lighting for a indie film, somehow I’m still a beginner in lighting, I used to do lighting with small power light, so I used to drag the household power,.Since I prepare to light a large scene , maybe need  to rent some large power HMI (4K or more)  which the household power  cannot afford, so what options can I have ?

 

I’ve thought of generator, but I’m not sure if the power is steady to operate high power light, also the noise issue.

 

I’ve heard of three phase electricity which most of lighting make use of, but I am not sure the theory and how to calculate the power, is there any advice on that ? Also normally where I can get the three phase electricity?

 

Thanks

 

 

There is a poster here, Guy Holt, who has a number of posts on the topic of general electrical, generators and lighting.

 

I would strongly advise, not doing anything with a type of power you are unfamiliar with. Since most people don't know what 3-phase, is, or how to wire it, the strongest advice would be to hire a certified electrician to direct any 'wiring' for lights using such.

 

At 4K Watts, my guess would be you need at least a 7K Watt generator. That 'excess' power is often required for start up transients where the equipment draws more power than it's 'average operational' power just to start up.

 

In the US the typical house current supplies either 15 Amps giving 1800 W max, or 20 Amps giving 2400 W max so, I would not use a light that takes more than 1K on a 15 Amp circuit, or  1500 W lights on a 20 Amp circuit.

 

Europe  uses 220/240 V at 10 Amps (I think... don't live in Europe, that's what I recall). But in any case, unless you are 'just plugging something into a standard socket... get a certified electrician...

 

And while we are at it... buy liability insurance for your production... and if you are not the producer, get the producer to show proof of insurance coverage.


Edited by jeclark2006, 25 July 2014 - 12:06 PM.

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#3 Leonardo Brocato

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Posted 25 July 2014 - 05:54 PM

To manage electrical distribution on set all over the world you need experienced people because it's really dangeruous, if you are in Usa in 110 v the three phase sistem it's a little bit different from mine and search for the Guy Holt's posts will be very helpful.

On set you must know the power you need and also the way you distribute, with luchbox or switches or simply in the size of the stingers or protections, it's like a puzzle but you need to know exactly all the size of every piece before.

It's sure that for a 4k hmi you need to have a generator at least 6/7Kw in europe generator manifaturers sell 2.5-5-10 kw monophase (the 5k doesn't strike the 4k) and for the threephase 6-12-15-30 until 1000kw.

In Italy for example we use the monophase sistem only for small loads until 10k, and the 10kw can power also a 6kw hmi or two 4kw hmi and a tungsten load until 9kw, but the most used it's the 5kw better if i'ts an Honda 5500 but not for 4k hmi.

The three phase sistem in italy it's like that:
one stinger five wires: R (power line) S (power line) T (power line) N (neutral) Ground (protection) 380v three phase sistem
between RS ST RT you have 380v with very few power loss on long distances.Then there is a big box that split the power from 380v to 220v (european  final voltage) picking R+N T+N S+N you have 3 phases or legs of 220v and you need also to balance them.
Big generators uses 380v and also dimmer racks uses three phase like 12x2.5kw 6x5kw or 3x10kw or 3x5kw
In italy we have 16amp in houses with 3kw of power and on set we use plugs like 16amps (3.5kw) 32amps (5-6kw) 63amps (10-12kw) 125amps (20-25kw) and for three phase it's 16amp (6kw 3x2kw) 32amps (15kw 3x5kw) 63amps (30kw 3x10kw) 125amps (3x20kw) after that we use a sistem simil to the cam lock with single wires called power lock from 250amps to 800amps with different size.
But you are not in 220v so it's for speaking :D 

 

Leonardo Brocato still connecting boxes and stingers of every size with passion and alot of fun 
Gaffer Roma Italy  


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#4 Shermen L

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Posted 26 July 2014 - 12:55 AM

Thanks a lot for reply, I'm in 220V, it seems I need an electrician on set, btw, just wonder if lighting up like ARRIMAX (18/12KW), I know the power is really large, I don't think there's  any portable generator can  support it. Is it normally to hire  a generator truck for that  or any other method to get the power ?


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#5 Leonardo Brocato

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Posted 26 July 2014 - 05:03 AM

If you are a 220v big size generators uses 3phase sistem (380v) and, for the Arrimax you absolutely need a generator truck because you need at least 50kw to power it, and in italy the 18/12 has a plug of 125amps. This means big boxes and big stingers, so you definetly need an electrician. Here you can request in the street a special line of power attached by the electric distributor of the city, you need a month before to do the request and it's a little bit cheaper than a generator, and the sound man will be very very happy.
Just try the elctrical distributor maybe can provide a special power line in a no long distance from set, in every corner of every street there are electrical boxes but i don't know if in your country there is this service.

 

Leonardo Brocato
Gaffer Rome Italy


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#6 freddie bonfanti

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Posted 27 July 2014 - 05:28 AM

Shermen,

 

like any other cinematographer you would benefit by starting a relationship with a good gaffer who will 'enlighten' (see what i did there?) your way into film lighting. A gaffer will be an invaluable help for all your future projects. If you're just starting out then maybe you can find a set electrician who is willing to step up and work as a gaffer on smaller project.

 

Film is all about collaboration. Surround yourself with good technicians. They have got all the answers you're looking for!


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#7 Phil Rhodes

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Posted 27 July 2014 - 08:57 AM

 Surround yourself with good technicians.

 

Freddie, we all want to do that, it's an issue of affordability.


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#8 timHealy

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Posted 27 July 2014 - 09:15 AM

 

 

I’ve heard of three phase electricity which most of lighting make use of, but I am not sure the theory and how to calculate the power, is there any advice on that ? Also normally where I can get the three phase electricity?

 

Thanks

 

 

If you want to learn about electricity I would do what I did when I got started, read books about basic electricity. Then you can step up to more complicated books about electricity. Its not really that hard to understand. In the film business you don't need to study so much to be an electrical engineer but you need to understand the basics. Then read the Harry Box book. Though his book is "Hollywood" oriented and describes U.S. electrical systems and codes. But it is helpful nonetheless.

 

Best

 

Tim


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#9 Guy Holt

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Posted 29 July 2014 - 06:36 AM

... if lighting up like ARRIMAX (18/12KW), I know the power is really large, I don't think there's  any portable generator can  support it. Is it normally to hire  a generator truck for that  or any other method to get the power ?

 

While the power draw of an 18kw ARRIMAX far exceeds the capacity of a portable generator, there is another option. Arri has just combined their MAX reflector technology with a new power class of HMI lamps to make a light that that can be run on portable generators and is as bright as some 18k Fresnels. This new light is the M90.

 

M90-60-Small.jpg

The light generated by the CAD designed Max Reflector of the new

M90/60 is incredibly bright and sharp.

 

Pairing a new 9 kW HMI lamp with the MAX reflector of the ARRIMAX, the new ARRI M90 creates diverging parallel rays to produce a crisp light with even distribution through a wide spot/flood range. The result is a lens-less open face fixture with a quality of light close to that of a Fresnel. The elimination of spread lenses like those used on HMI Pars makes the ARRI MAX reflector lamp heads comparable in output to par configurations of a higher wattage. In fact, the M90 is brighter than some 18K Fresnels on the market.

 

M90_Ballast_Small.jpg

The Active Line Filtration (ALF) of the new ARRI EB 6000/9000 ballast

makes it an incredibly efficient and clean load.

 

To power the new M90 head, ARRI has engineered a dual wattage ballast (6 & 9kw) with Active Line Filtration (ARRI's system of Power Factor Correction.) The advanced electronics of the ballast makes it incredibly efficient and it generates virtually no harmonic noise.

 

EU_6500_Parallel_Pkg_w_M90_Sm.jpg

 

The combined  100A output of paralleled Honda EU6500s is sufficient to operate

the new Arri M90 as well as additional set lighting.

 

Drawing only 84 Amps, the M90 can operate on the combined 100A output of paralleled Honda EU6500s. Not only is this approach a lot less expensive than using an 18kw ARRIMAX, it is also a lot easier and offers more versatility. It is a lot easier because you don’t have to tow a diesel generator or run heavy feeder. It is more versatile because when you don't need the punch of a 18kw, you can swap the 9kw globe for a 6kw globe making more power available to run additional lights on the paralleled EU6500s. For example, you save 27 Amps when you swap out a 9kw bulb for a 6kw bulb. The 27 Amps you save by burning the smaller 6kw globe will power quite a few more lights when you consider that both the ARRI L7 LED Fresnel and Kino Flo Parabeam 400 use approximately 2 Amps. Use this link for more details about this approach.

 

Guy Holt, Gaffer, Lighting and Grip Equipment Rental & Sales in  Boston


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