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Power for mole Richardson 5k fresnel and 2k fresnel


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Okay guys A couple questions. I love to incorporate the mole Richardson units in my photography. I love the vintage look and the beautiful light they produce. Now I have some questions about powering these lights...

 

1. Can I put a less wattage bulb in these fixtures and run them on standard household power? For example can I take the 2k bulb out and say put in a 1500 watt bulb? My light fixture also has a bates connector instead of a Edison plug so I went ahead and bought the adapter to connect the two. This unit is 20 amps.

 

2. Now for the 5k I have pretty much the same question. There is no way I can run a 5k off of a standard household outlet without probably calling out a professional electrician. However what if I put a 1500 watt bulb in the unit ? Would this allow me to do something like that since I am cutting the power down? I also realize I would need a Edison adapter for this since it is 60 amps and it came with a bates plug. I have had no luck finding a 60 amp Edison adapter except from rental houses.

 

The most obvious choice is to scale down my lights and purchase a less wattage light outright but I really like the look of the big units as props on photographs I am taking. Sorry if this is confusing. Thanks for the help!

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Yes to the 2K, you can put a 1500w globe in it, but you can also run the 2K as is off a 20A circuit. Re-lamping the 5K would be more complicated. It would require a socket change and a riser to bring the 2K socket up to the point where the filament would be centered in the reflector.

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Where are you located?

 

 

We've put mounts inside 5ks to hold a flash head. Matthew Rolston shot a lot of his portraits using a Mole 5k with a Profoto twin head inside.

 

 

I also have a 2k Arri whee I drilled through the back and mounted a Profoto adapter ring.

 

Yup 4" Hole through the back of the Arri Studio 2k.

 

 

If you are just using them as props then rigging a different lamp base for a lower wattage tungsten globe inside is relatively easy.

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Yes to the 2K, you can put a 1500w globe in it, but you can also run the 2K as is off a 20A circuit. Re-lamping the 5K would be more complicated. It would require a socket change and a riser to bring the 2K socket up to the point where the filament would be centered in the reflector.

thank you! I look forward to finally being able to try my 2k out! :)
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Thanks Edward! I love both of those ideas actually. I did come across a adapter from mole Richardson that lets you mount 2k bulbs in a 5k fixture. Let me know what u think https://www.bhphotovideo.com/c/product/167597-REG/Mole_Richardson_1921_5KW_to_2KW_Socket.html

 

Could this work?

 

That will work but as you mentioned you'll have to step down from the 60amp bates connector to an Edison.

 

You can get the 60amp bates from Film Tools 32 bux and then wire it to a piece of 12/3 cord and an Edison connector.

 

http://www.filmtools.com/grip-and-electrical/electrical/ba60ampcapl.html

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  • 3 weeks later...

... There is no way I can run a 5k off of a standard household outlet without probably calling out a professional electrician.

 

There is a lot of good information in this thread, but I don’t agree with the premise that a professional electrician is required to run a 5k off of a standard household outlet. This statement is not completely accurate. There are a number 240-volt wall outlets in a typical house, office, or industrial plant that you can safely and legally use to power a 5k. The most common are air conditioner outlets, dryer outlets, range outlets, outlets for large copy machines in offices, and the outlets for motorized equipment and compressors in industrial plants.

 

If you look at the breaker of these circuits on the building service panel you will notice that they use two pole breakers - either 30A or 50A. Each pole of the breaker is in a sense an independent 30A or 50A 120 volt circuit. That is, if you measure the voltage from each pole of the breaker to ground it will be 120 volts, and if you measure the voltage between the two poles of the breaker you will notice that it is 240 volts. The 120 volts of the two poles adds up to 240V because the 120V circuits are on opposing legs (and are therefore additive) of either a single-phase electrical service of a house, or a single phase secondary step down transformer of a office or industrial plant. In residential settings, this is how higher voltages are supplied to household appliances like Dryers, Electric Ranges, Air Conditioners, Motors, etc. that require more power than can be reasonably supplied by a single 120V circuit. Many of these household and industrial 240V receptacles use a three wire system (no neutral) because they are designed to power single phase motors or heating elements that draw a perfectly balanced load and return no current because the single phase service legs are 180 degrees out of phase and cancel each other out.

 

You have two options when it comes to running 5ks on these common residential 240V circuits. The first is to use a 5k with a 240V bulb. The 5k head has to be specifically designed to operate at 240V with a double throw switch (switches both hot and neutral simultaneously. So before you throw a 240V 5k globe in that Mole 5k, you need to confirm that it has a double throw switch. If not you will have a hazardous situation where the lamp is energized without a return. You don’t want to become the return path to ground. If it does have a double throw switch you will also probably need an adapter to plug into the 240V outlet because most 5ks are wired with a 60 Bates plug.

 

The second and safer option is to use a 240v-to-120v step-down transformer to power a standard 120V bulb. A transformer will convert the 240 volts supplied by the 240V receptacle to 120 volts in a single circuit that is the sum of the two single phase legs. A transformer can convert a 30A/240V Dryer Receptacle into 60A/120V Amp circuit which will be sufficient to power a 5k 120V globe since it draws 42 Amps.

 

I regularly use transformers to power not only 5ks, but also big HMIs (2.5-4Kw) in situations where a tie-in is not an option and the budget doesn’t permit for a tow generator. For example, I have used this approach repeatedly at a historical mansion in Easton MA called the Ames Estate.

 

Transformer-Distro_Sam1.jpg

Scene from "Unsolved History" powered from 50A/240V range outlet through step-down transformer/distro at the Ames Estate.

 

A popular state fee free location, the Ames Estate, like many historical house/museums, does not permit tie-ins and the electrical wiring in the house is so antiquated that it is unusable. Fortunately, they have a 50A/240 volt circuit in the carriage house for a welder they use to repair the mowers they use at the park. Our standard mode of operation when shooting there is to run 250V extension cable from the welding receptacle to our 60A Full Power Transformer/Distro placed in the entry hall of the house. Using a 60A Siamese at the Transformer/Distro, we then run 60A 6/3 Bates extensions, down to the library, to the second floor, and back to the maid’s pantry. At the end of each run we put another 60A Siamese. A 60A snackbox on one side of the Siamese gives us 20A branch circuits. The other side we leave open for a large HMI or Quartz Light. Now we can safely plug 1200 & 2500W HMIs, or even a 5k Quartz, into our own distribution anywhere in the house.

 

tmfilmstrip1lg.jpeg

Typhoid Mary in quarantine on an island in New York's East River. Note the view out the window of the East River shoreline at the turn of the century.

 

To maintain continuity between shots on these dramatic historical recreations, we usually bring a 4kw HMI Par or 5k Tungsten Fresnel (depending on the effect we are after) in a window on one side of the room as a sun source and a 1200 par through a window on the other side as a northern light source. Lights positioned outside, we power off of our modified Honda EU6500is through a Transformer/Distro. We are able to power both lights off our modified EU6500is because our 60A Full Power Transformer/Distro steps down the enhanced 7500W output of the generator to a single 60A/120V circuit (for more details on how this is accomplished I suggest you read my newsletter article on the use of portable generators in motion picture production available on our website.)

And, since the Honda EU6500is can be placed right on the lawn, we are saved from running hundreds of feet of feeder back to a tow generator in the drive.

 

tmfilmstrip2lg.jpeg

The exterior of the actual location used for the quarantine island. A 30' blowup of a picture of the East River at the turn of the century was rigged outside the windows of a house in Arlington MA.

 

We have been able to use this same basic distribution package (two Transformer Distros, 1- modified EU6500is) at numerous museums and historical houses throughout New England including Sturbridge Village. Fortunately for us, to make ends meet, many historical houses rent themselves out for events and weddings. For that reason, they usually have at least one updated service with 30 or 50 Amp 240 volt circuit for the warming ovens of caterers. I have included in this post several production stills from these shows. For those who would like to see samples of what can be accomplished with this basic package, I have attached these links to production stills of the PBS and History Channel historical documentaries shot entirely, or in part, with just a couple of transformers and a Honda generator.

 

The History Channel’s “Unsolved History” episode “Presidential Assassins”

 

American Experienes Typhoid Mary Biography “The Most Dangerous Women in America"

 

PBS’s Ben Franklin Biography “Franklin"

 

Or, use this link for more details about using step-down transformers on set.

 

By giving you safe and legal plug-in access to more house power through common 240V house outlets, a transformer can quite often eliminate the need for tie-ins or generators.

 

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

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