Need to rent a portable generator for lights...

[DVX100Shooter]

What would be an ideal generator to use for lighting work? I will be shooting at a location both outside and indoors. For the indoor shoot, I wanted to use a lot of lights. The exact number and wattage is still be planned out. I may need more than one generator. As I am researching this, I am finding that maybe using an Inverter might be better in terms of noise that a generator would make. I was looking at some of the Honda generators that can handle 2-3000 watts. I may need more wattage depending on the kind and wattage of the lights. I can say that I would like to use 2.3 Kino Flo's or possibly 2 LED 1x1's, 3 spotlights, about 3-4 black light bars and a few other lighting mechanisms. Now most of these lights would not need to be on at the same time. However they will need to be on when I am not shooting using the blacklights.

Just trying to get some feedback on what to use and what size generator or inverter would be best to use. I am shooting both outside and indoors. I don't want to plug all lights in the location I am shooting and risk blowing a circuit so I felt going with generators or inverters might be better. I am not talking about the kind that you tow behind your truck. These are small enough for one or maybe 2 people to carry.


Any thoughts.

 

[craigbowman]

I've rented and used Honda 6.5kw generators quite a few times to power everything from HMIs to kinos no problem. You can wheel them around and load 'em on a pickup truck or in the back of a rental van or what have you.

 

[ian dart]

if you are only using flos and leds with a couple of incandescants i would have thought that there would be enough power from the house to run them.

do a recce and find out how many power circuits there are in the house and their amperage limits.(10 amp 16amp etc) they usually run the left side right side/back front/upstairs downstairs to separate circuits.

work out the total wattage on each light, (keno diva 4 x 55w =220w divided by 110v =1.9 amp)....... divide by the voltage to get each lights amperage.

you will then know how many lights you can put on each circuit. always leave a bit of headroom so the fuses dont overheat.

 

[DVX100Shooter]

I am shooting inside a night club so it may be okay to just plug into the house outlets. The shoot does call for some exterior shots. How well do Kino's work outside? I would be shooting early morning just as the sun comes up. Am I better off going with a HMI for a stronger punch? If so, I will probably have to use a generator for those lights.

 

[Paul Hudson]

If you rent a small generator Honda is the only way to go.

 

[slondon]

If you rent a small generator Honda is the only way to go.

Agreed, and if you rent two 2000W Honda inverter generators they weigh 40 pounds each, are quiet and with an appropriate harness you can connect them together for almost 4000W.

I have a Honda EU3000is super quiet inverter generator and it is a gem.

 

[DVX100Shooter]

very cool...Thanks!

 

[nejuicer]

What would be an ideal generator to use for lighting work? .... I am not talking about the kind that you tow behind your truck. These are small enough for one or maybe 2 people to carry. Any thoughts.

DVX100Shooter, use the Honda EU6500is even if you have to go a film rental house to rent it. You could use a home-depot type of generator, but only if you were using incandescent lights (not the most efficient source) and not using the generator as your primary supply for tech and you are not recording sound. But since you want to use HMIs , Kinos, LEDs, and record sound, it matters not only what type of generator you use but also what type of ballasts the lights use. The harmonic noise that magnetic and non-PFC electronic ballasts (both HMI & Kino) kick back into the power stream can have a severe adverse effect on the power waveform of conventional AVR generators like those available from Home Depot. The harmonic noise these light sources generate will not have nearly as bad an effect on the power supplied by an inverter generator like the Honda EU6500is. The Honda EU6500is will also generate less than half the noise of Home Depot type generators – making it easier to record clean audio tracks. For more details on what type of generator to use with HMIs and fluorescent lights read the article I wrote for our company news letter on the use of portable generators in motion picture production.

This article is cited in the just released 4th Edition of Harry Box's "Set Lighting Technician's Handbook" and featured on the companion website "Box Book Extras." Of the article Harry Box exclaims:

"Great work!... this is the kind of thing I think very few technician's ever get to see, and as a result many people have absolutely no idea why things stop working."

"Following the prescriptions contained in this article enables the operation of bigger lights, or more smaller lights, on portable generators than has ever been possible before."​

The article is available online at http://www.screenlightandgrip.com/html/emailnewsletter_generators.html.

Guy Holt, Gaffer, ScreenLight & Grip, Lightng & Grip Rental in BostonGrip

 

[mkfotos.com]

Another vote for Honda EU series generators. Basically any sensitive electronics (HAM radios, studio lights, etc.) can run smoothly and safely from them. Typical/cheap generators produce what's known as a square wave (the ugly looking green trace in the above left pic), while the EUs produce a true sine wave (the nice, smooth looking trace on the right).

 

[nejuicer]

As I am researching this, I am finding that maybe using an Inverter might be better in terms of noise that a generator would make.

An inverter has limited capacity. The largest true sine wave inverter available is only 1800W and would require a bank of 70 Amp Hr marine cells to run very long. I built the rig pictured below to operate just four 4’-4 Bank Kino fixtures in an airport shuttle bus for the feature “Shuttle.”

1800W "Batt-Verter" Rig wired into the back of Shuttle​

The only reason we were able to get by with just two marine cells is that we tied the batteries into the alternator of the shuttle so that it charged the batteries while the engine was running. If we hadn’t done that we would have needed a lot more batteries. Where you are not moving like a shuttle, I would recommend a generator over inverters.

If you use a Honda EU6500is inverter generator, it is possible to record location audio without picking up generator noise - especially if you use them with a transformer/distro. The Honda EU6500is inverter generator to begin with is much quieter than the other portable generators and even Honda’s older movie blimped Honda EX5500. Part of what makes the new Honda EU6500is so quiet is it's "Eco-Throttle." The Eco-Throttle's microprocessor automatically adjusts the generator's engine speed to produce only the power needed for the applied load. It can do this because the inverter technology of the Honda EU6500is enables it to run at different RPMs and maintain a constant frequency and voltage. Where conventional generators like the Honda EX5500 and ES6500 have to run full speed at a constant 3600 RPM to produce stable 60 hertz (cycle) electricity, a Honda EU6500is only needs to run as fast as required to meet the load demand. Since their engines do not have to run at full speed, and given the fact that an inverter generator generates 20% more power per revolution of the engine, makes the Honda EU series of inverter generators substantially quieter than conventional models.

The net result is that the EU6500is operates between 34 to 44 dBA at 50 ft. - half as loud (ten decibels) as the comparable EM7000is and ES6500 generators and comparable to our Crawford 1400A. But you can't park a Crawford right on set and record sound without picking up the generator either. With sound specs this good all you need to record sound without picking up generator noise is a real distro system that will allow you to move the EU6500is off set (like you would a Crawford), minimize line loss over a long cable run, and provide plug-in pockets conveniently close to set. That is where the transformer comes in.

A Distro System consisting of a 60A Full Power Transformer/Distro, 2-60A GPC (Bates) Splitters, 2-60A Woodhead Box distributes power from a modified Honda EU6500is. Even though the generator is 100' away to reduce noise, plug-in points remain conveniently close to set.​

To record sync sound without picking up any generator noise, all you need to do is add 200' of heavy duty 250V twist-lock extension cable between the generator and a transformer/distro. This is usually enough cable to place the generator around the corner of a building, or to run it out of a van or truck - which is usually all the additional blimping you need with these generators. The heavy-duty 250V twist-lock cable eliminates multiple long cable runs to the generator and minimizes line-loss; as well as, eliminates the voltage drop you would have using standard electrical cords.

60A GPC (Bates) Splitters and Woodhead Box.​

To assure full line level (120V) on set, use a transformer/distro designed to compensate for line loss you will have over an extended cable run. That is, use one designed to slightly boost the voltage on the load side (secondary). With these "boost transformers," if you were to feed the supply side (primary) of the transformer 240 volts from the generator, 127 volts would come out on the secondary side where you plug in the lights. This slight boost enables you to place the generator further from set where you won't hear it, yet assure that the supply voltage on set does not drop too low. Make sure the transformer/distro is equipped with a 60A Bates and three 20 A Edison circuits so that you have plug-in pockets conveniently on set.

60A Woodhead Box running Power-to-Light PFC 800W ballast (left) and PFC 1200W ballast (right.)​

For more details on the use of transformers for set power, I suggest you read the article I mentioned previously. Use this link -
www.screenlightandgrip.com/html/emailnewsletter_generators.html - for more information about using inverter generators with transformers for motion picture lighting.

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