4k hmi off house power

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lagrip

New member
Have a question about 4k HMI and house power. First of all what kind of power cord comes out of the ballast. I work alot of small indy films and would like to give my clients the option of using this beast off of house power.. My question is Is it possible to make a converter box to run off the washer/dryer or stove outlet?

questions/comments any help would be nice

thanks
 
Not knowing exactly what you are talking about makes it difficult. Usually 5k's and higher become stagepin, while lower wattage lights tend to be edison.


My best guess on a 4k is edison (house hold).

It is VERY common to use "lunch boxes" these tap into those higher amp 'dryer/stove' outlets and then break off into (usually) 5 circuits. Lunchboxes are very convenient. Just make sure the lunchbox does not need an adapter, because you would be surprised at how many variations of those connections there are.
842180602_840e53ce70.jpg


This picture is similar to the ones I use, too bad it's facing the other way, because you can't see the connections. Basically it plugs into your 'dryer' connection and then turns that heavy current into 5 circuits on separate breakers. Usually two Edison plugs per circuit.
 
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HOLD ON!

Edison is only rated to 15amps, and can be pushed to 20amps easily. But 4000w (roughly 40amps), are you nuts??

To be safe, you need at least a 40amp circuit juicing this. I assume this needs a 110v supply? You could make a "dryer drop" system but use cables and plugs rated to carry 40amps and use a range plugin (which are usually 50amp circuits).

I regularly power my 2500w HMI off a dryer plug.

Be careful or you will burn a house down.
 
hey shawneous thanks for the reply. yeah thats exactly what im trying to do is run a 4k off a dryer plug. do you have any pictures or instructions on how to make a converter box?
 
lagrip said:
hey shawneous thanks for the reply. yeah thats exactly what im trying to do is run a 4k off a dryer plug. do you have any pictures or instructions on how to make a converter box?
Click to expand...

Pretty sure most dryers are only 30 amp. Ranges are usually 50.
 
cant speak from experience but would a 4kw HMI ballast even have a 120v line connection? Seems to me something that high would require a 220v input.

to answer one of your questions, the power cord coming out of the ballast is a ballast to head connection. The power cord going in is a source or line or mains connection.
 
...well my stove is on a 120/220v breaker so thats why im thinking it could be possible. but then again shawneous says he does it all the time.
 
lagrip said:
Have a question about 4k HMI and house power. First of all what kind of power cord comes out of the ballast. I work alot of small indy films and would like to give my clients the option of using this beast off of house power.. My question is Is it possible to make a converter box to run off the washer/dryer or stove outlet?

questions/comments any help would be nice

thanks
Click to expand...


An Arri 40/25 HMI PAR will draw either 34 amps at 120 volts or 17 amps at 220 volts (depending on how its lamped) so the ballast will most likely have a 60 amp Bates plug which would need to be plugged in to a lunchbox via a 100 amp to 60 amp splitter, or a distro box via the same splitter.

A lunchbox is set up as a "flow though" box fed 100 amps and has 5 circuits of 20 amps each for edison plug use and 100 amp Bates jacks on 2 sides of it.

You could run a 4K off the stove or laundry drier circuit of house wiring at 220 volts.

.
 
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4K hmi off house power

4K hmi off house power

Shawn Philip Nelson said:
I assume this needs a 110v supply? You could make a "dryer drop" system but use cables and plugs rated to carry 40amps and use a range plugin (which are usually 50amp circuits).
Click to expand...


2.5-4kw HMIs with power factor corrected 240V electronic ballasts can be plugged directly into 240V Dryer Outlets with an adaper. But, you have to be really careful when splitting 240 volt circuits with a “dryer drop” to power large 120V HMI ballasts as discussed in this thread. If the 240 volt circuit is a four wire system (the receptacle has four slots: one for ground, one for neutral, and two for hot), one can use a distro box that splits the two hot circuits as long as it is wired so that each circuit has a ground and neutral.

Where you run into trouble is when the 240V circuit uses a three wire system (the receptacle has three slots: one for ground, and two for hot, and no neutral.) Many older household and industrial 240V receptacles use a three wire system (no neutral) because they were wired for the sole purpose of powering single phase motors or heating elements that draw a perfectly balanced load and return no current. A perfectly balanced load doesn’t require a neutral because the single phase service legs are 180 degrees out of phase and cancel each other out – hence there is no return that would require a separate neutral (a later revision to the NEC required all 240V circuits to include a neutral.)

You run into trouble with this kind of circuit because your 120V HMI ballast will invariably pull an unbalanced load on your splitter distro box. That’s because under most production situations you can never perfectly balance your lighting load, especially when it in consists partly of a large HMI. If your load is not perfectly balanced the two 120V circuits that make up this 240V circuit will not have 100% phase cancellation and the extra current of the high leg will not have a safe return path because by necessity with a three wire system you have had to bond the ground and the neutral in the splitter box (after all what else can you do with the ground and neutral of your splitter box but to bond them when plugging into a three wire 240V circuit.) Not only is it unsafe, but bonding ground and neutral after the service side of a main service head is a violation of the National Electrical Code (NEC.) To quote Mike Holt, of Mike Holt Enterprises, Inc. (A Leading Electrician Training Program in FL): “The National Electrical Code requires a neutral-to-ground connection to be made at service equipment only and there shall not be any neutral-to-ground connection on the load side of service equipment [250-23(a), 250-24(a)(5)]” (full excerpt is available online at his website www.mikeholt.com)

The only safe way to pull power from three wire 240V circuits is to run your lighting load through a 240v-to-120v step down transformer. A transformer converts the 240 volts supplied by these industrial and household 240V receptacles back to 120 volts in a single circuit that is the sum of the two legs of the circuit. For instance, a transformer can make a 60A/120v circuit out of a 30A/240v dryer circuit that is capable of powering bigger lights, like the 4k in question. What makes it safe to use a step town transformer with three wire 240V dryer/range/motor circuits is that the transformer automatically splits the load of whatever you plug into it evenly over the two legs of the 240V circuit. Where there is no high leg, the loads on each leg of the 240V circuit cancel out and there is no return that would require a separate neutral.

And unlike 240V splitter distro boxes where you have to meticulously balance your load, a transformer greatly simplifies your set electrics by automatically splitting the load. As long as you plug lights in through the transformer, you no longer have to carefully balance the load over the two 120V circuit/legs because the transformer does it for you automatically. If you outfit the transformer with a 60 Bates receptacle, you can use 60A GPC extension cables, 60-to-60 Splitters, and fused 60A GPC-to-Edison Breakouts (snack boxes) to run power around set - breaking out to 20A Edison outlets at convenient points (rather than one central point.) The best part about using a transformer with a 240V receptacle in this fashion is that no matter where in the distribution system you plug in, the transformer automatically balances the additional load, so that you don't have to.
I use transformers to power bigger HMIs (2.5-4Kw) in situations where a tie-in is not an option and the budget doesn’t permit for a tow generator. Where the production budget is particularly tight, I use a package consisting of two transformers and a portable generator. I use one transformer to access more power through a 240V circuit on location to run lights inside; while the other I use to bring larger HMIs in the windows from outside. This approach eliminates the need for a dangerous tie-in or expensive tow generators, it also greatly reduces the amount of cable that has to be run.

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” : www.screenlightandgrip.com/html/unhisintro.html

American Experienes Typhoid Mary Biography "The Most Dangerous Women in America": www.screenlightandgrip.com/html/tmintro.html

WGBH’s Ben Franklin Biography “Franklin”:
www.screenlightandgrip.com/html/franklinintro.html

Or, use this link for more details about using step-down transformers on set: www.screenlightandgrip.com/html/hd_plug-n-play_pkg.html
By giving you 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, www.screenlightandgrip.com
 
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