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How to blimp a 6500W Honda generator?

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Willy Faes

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I am planning a shoot next month in a forest and I'd like to use a 6500W Honda generator. I have 100 meter (328 feet) of cable at my disposal. The generator is rather noisy so I want to blimp it. Has anyone done this or has any idea how to do this?

Thanks

Willy Faes
 
Not 100% effective, but building an earth wall around it cuts the direction of the sound. if you do three walls with the open away from your shoot direction, then put something like foam or a small mattress or something over it may help a lot.
 
I've built a 3 walls and a roof plywood and foam pad enclosure for the 6500's - It's not that effective, but if it's over a hill and downwind you might get away with it. It's being acceptable mostly depends on how much other background noise there is present. One shoot years ago in Mendocino we were able to rent a solar panel, battery, inverter array that worked pretty well and of course was completely silent.

Matt Uhry
www.mattuhry.com
 
Matt, there is almost no other background noise but I'll do some tests with a 3 wall + roof construction.

Thanks

Willy Faes
 
Being in the woods makes it harder, But a friend of mine did this in a village in Afghanistan with a construction generator -

Rent a bobcat, dig a trench, put the genny in the trench. Cover the top of the trench with 4x4s and a sheet of plywood, put the dirt from the trench on top of the plywood. But really, at this point, just rent a blimped genny ;-)

Nick
 
Willy Faes said:
I am planning a shoot next month in a forest and I'd like to use a 6500W Honda generator. I have 100 meter (328 feet) of cable at my disposal. The generator is rather noisy so I want to blimp it. Has anyone done this or has any idea how to do this?
Click to expand...

A little more information would be helpful. What model 6500W Honda generator do you have access to? What is the gauge of the 100m of cable? Is that 100m per light or does that have to be split up between lights? In other words, how far away can the generator be? What lights are you using?

Peter Berger
 
come out of the 220/240 30 amp plug of the genny , then do a run of that style cable , then a 480240to240/120 step down transformer.. then exit the transformer with 120 bates , you can get hundreds of yards on retail fairly cheap , that should get you very far , generators, do not like ambient heat around them , put a fan on it , if its going to be buried or blimped , and mess around with lag mics, or get a boom op with a 816 that has a super narrow precise pattern , but a novice with a 816 is a whole different problem .
 
Peter Berger said:
A little more information would be helpful. What model 6500W Honda generator do you have access to? What is the gauge of the 100m of cable? Is that 100m per light or does that have to be split up between lights? In other words, how far away can the generator be? What lights are you using?

Peter Berger
Click to expand...

Peter

The generator is a EU65is (European model). The lights we are a 4kW and a 1.2kW. We can use to cables, one for the 4kW and a another for the 1.2 kW. I don't know what the gauge is of the 100m cable is.

Willy Faes
 
weird, i just took 10 minutes, explaining the problems you might encounter , aside from sound, as in 4k and 1.2 k hmis , on one circuit in that genny.
your neutral leg being undersized for the return leg of that proposed circuit . like reducing a firehouse to a garden hose " back pressure " .. so you may have flicker , even if it doesn't pop the breaker from being over-amped.
i would look into renting a 2000 watt inverter also , to run the 1.2 k while the eu6500is runs the 4k , that genny will screeeeeeam while trying to put out 6k for hours

thus , the step-down , thats what i do with mine and why

good luck , it can be done , just not a easy task
 
chad vachter said:
weird, i just took 10 minutes, explaining the problems you might encounter , aside from sound, as in 4k and 1.2 k hmis , on one circuit in that genny.
your neutral leg being undersized for the return leg of that proposed circuit . like reducing a firehouse to a garden hose " back pressure " .. so you may have flicker , even if it doesn't pop the breaker from being over-amped.
i would look into renting a 2000 watt inverter also , to run the 1.2 k while the eu6500is runs the 4k , that genny will screeeeeeam while trying to put out 6k for hours

thus , the step-down , thats what i do with mine and why

good luck , it can be done , just not a easy task
Click to expand...

While Chad’s approach would work with one of the enhanced 7500W EU6500is (US model), it won’t work with the EU65is (European Model.)
Here’s why. The US model can be modified to generate 7500W at 240V. The company that modifies the generators also builds a custom 240-to-120V step-down transformer/distro that converts the enhanced 240V output to a single 60A/120V circuit (they also now build a transformer/distro that provides a 84A/120V circuit from Hondas new 10kw EB10000 generator.) The transformer/distro has a 60A Bates receptacle so that you can use standard film distro to plug both the 4k and 1.2 HMI into the transformer/distro. If the 4k has a Power Factor Corrected (PFC ) electronic ballast that will draw 38A and the 1.2 also has a PFC ballast that will draw 11.5A, the combined load of 49.5A is well within the capacity of the 60A/120V circuit provided. As an added benefit, these transformer/distros have selectable voltage boost taps that enable you to compensate for voltage drop over a long cable run and the voltage drop you will have on the generator when you fully load it. This feature enables you to operate the generator at a distance where you won’t hear it, yet maintain full line level on set to your lights so that they don’t cut out from low voltage (a chronic problem using HMIs on portable Honda generators.) So, Chad’s suggestion is a good one if you had access to a US model EU6500is.

Chad’s suggestion won’t work with the European model EU65 because that model is configured with three 16A/240V receptacles. A step-down transformer/distro plugged into one of these receptacles will only provide a 32A/120V circuit, which is not large enough to power the 4k which draws minimally 38A at 120V with a PFC electronic ballast. Even though most electronic ballasts are multi-volt ballasts, and will operate at 240V, you won’t be able to operate it safely at 240V off the generator because its’ 240V load of 19A will overload the 16A/240V circuit on the EU65is. The new 10kw Honda EB10000 has a 50A/240V twist-lock receptacle from which you can pull a max of 41.6A at 240V (enough to run even a 6kw HMI), but unfortunately that model is not available outside the US.

I would suggest swapping the 4k HMI for the new 1800W Arri M18 with Arrimax reflector. The M18 will give you output comparable to that of a 4kw Fresnel, but only draw about 10A at 240V, so you will be able to plug it into the 16A receptacle of the European model EU65is. The EU6500is (both US and European models) are quiet enough that you should have no difficulty getting clean audio with proper miking if you run the generator out of your grip truck or van 100m away.

Good Luck

Peter Berger
 
Peter Berger said:
While Chad’s approach would work with one of the enhanced 7500W EU6500is (US model), it won’t work with the EU65is (European Model.)
Here’s why. The US model can be modified to generate 7500W at 240V. The company that modifies the generators also builds a custom 240-to-120V step-down transformer/distro that converts the enhanced 240V output to a single 60A/120V circuit (they also now build a transformer/distro that provides a 84A/120V circuit from Hondas new 10kw EB10000 generator.) The transformer/distro has a 60A Bates receptacle so that you can use standard film distro to plug both the 4k and 1.2 HMI into the transformer/distro. If the 4k has a Power Factor Corrected (PFC ) electronic ballast that will draw 38A and the 1.2 also has a PFC ballast that will draw 11.5A, the combined load of 49.5A is well within the capacity of the 60A/120V circuit provided. As an added benefit, these transformer/distros have selectable voltage boost taps that enable you to compensate for voltage drop over a long cable run and the voltage drop you will have on the generator when you fully load it. This feature enables you to operate the generator at a distance where you won’t hear it, yet maintain full line level on set to your lights so that they don’t cut out from low voltage (a chronic problem using HMIs on portable Honda generators.) So, Chad’s suggestion is a good one if you had access to a US model EU6500is.

Chad’s suggestion won’t work with the European model EU65 because that model is configured with three 16A/240V receptacles. A step-down transformer/distro plugged into one of these receptacles will only provide a 32A/120V circuit, which is not large enough to power the 4k which draws minimally 38A at 120V with a PFC electronic ballast. Even though most electronic ballasts are multi-volt ballasts, and will operate at 240V, you won’t be able to operate it safely at 240V off the generator because its’ 240V load of 19A will overload the 16A/240V circuit on the EU65is. The new 10kw Honda EB10000 has a 50A/240V twist-lock receptacle from which you can pull a max of 41.6A at 240V (enough to run even a 6kw HMI), but unfortunately that model is not available outside the US.

I would suggest swapping the 4k HMI for the new 1800W Arri M18 with Arrimax reflector. The M18 will give you output comparable to that of a 4kw Fresnel, but only draw about 10A at 240V, so you will be able to plug it into the 16A receptacle of the European model EU65is. The EU6500is (both US and European models) are quiet enough that you should have no difficulty getting clean audio with proper miking if you run the generator out of your grip truck or van 100m away.

Good Luck

Peter Berger
Click to expand...

Peter, thank you for your explanation but we already us our 4kW + 1.2 kW with success with the 65EU generator. I think there is one 20A receptacle. My main concern is how to make the generator less noisy.

Willy Faes
 
Willy Faes said:
…we already us our 4kW + 1.2 kW with success with the 65EU generator. I think there is one 20A receptacle.
Click to expand...

Unless your particular machine was modified by a third party, according to the wiring schematics for the EU65is in front of me, there are only three 16A receptacles. Since, according to the wiring schematics there is no over current protection for each 16A receptacle, you are probably overloading the 16A receptacle without realizing it (have you ever put an amp probe on your ballast?)

We do the same in the US with 1200W HMIs on our 15A receptacles. That is we are able to successfully operate (for the most part) non-PFC 1200W HMIs that draw about 18A at 120V on standard 15A U-Ground Edison connectors. Where we run into trouble is when we try to use long cable runs. Since most electronic HMI ballasts are what are called “constant power” ballasts, as voltage drops from line loss over a long cable run, the ballast draws more current (Amps), to maintain constant power to the head. Over a long cable run, the non-PFC 1200W HMI that drew about 18A at 120V, draws over 20A at 105V and melts the 15A connectors on the extension cable. The same may happen to you if you try to operate the generator at a great distance from your set without using a transformer to compensate for the voltage drop on the generator and line loss over the long cable run. For that reason I would use a "buck boost" transformer on set to compensate for the voltage drop so that you can operate the generator at a distance where you won't hear it.

Peter Berger
 
Peter,
Blimping a generator means making it quiet enough to be able to record on-set sound while it is running. That could mean moving it very far from the set, putting it into a more soundproof container, or a combination of both.
 
Thanks Peter. I'm not really a tech guy so I check this with my gaffer. I know we have PFS ballasts so this will help.

Willy Faes
 
If you dig a trench to place it in as Nick says, PLEASE be careful. The CO from the exhaust, being heavier than air, will collect in the trench, making a "death zone" for the hapless electrician who climbs down to refuel the Honda. Running a metal ductwork up and out from the exhaust pipe MAY or MAY NOT help. Don't let someone go down by themselves.
Honestly, by the time you rent a bobcat, buy plywood and build a shelter, or some other such technique, you probably are close to even money on a real blimped genny. The small difference is probably worth the hassle factor. And as Peter pointed out, the voltage drop from running long extension cables can produce show-stopping results (melted plugs, lights that will not fire, lights that flicker)
Check for independent owner operators near you. I know guys who put small blimped models (under 700 amps) inside Sprinter vehicles. Very compact, and usually a pretty good bargain.
Cheers,
Harry
 
Willy:

The EU65is is a pretty darn quiet genny to start.

I have a collapsible blimp kit for that very genny. Go to a DIY hardware store, like Home Depot and get a few pieces of 1 to 1.5" PVC pipe and some 3-way corner tees. With these, you can build a skeleton frame that goes over the genny. Drape sound blankets over the frame. Make sure to build a frame large enough to leave space between the frame and the genny. Also point the exhause side away from the scene and, leave an opening in the sound blankets for the exhaust.

They also sell 3rd party exhaust kits for the Honda on Ebay. With these, you can build a permamnant soundproofing enclosure.

Peter: Honda makes at least 4 different versions of the EU65 for the various EU countries. I have all of the wiring diagrams and there are different combinations of receptacles and overload protection.
 
You will want to leave a 3' air space around the generator for cooling. Also when trenching line the bottom or you may have a hard time getting your 300lb generator out at the end of the shoot when everybody is tired.
 
Michael Panfeld said:
The EU65is is a pretty darn quiet genny to start.
Click to expand...

I have to agree with Michael. A mountain is being made out of a mole hill. The Honda EU65 is extremely quiet by portable generator standards and nearly as quiet as a full size Crawford movie blimped generator. But you can't park a Crawford right on set and record sound without picking up the generator either. To record sound without picking up generator noise you will need to move the EU65 well off set just like you would a Crawford. If you run the generator out of your grip truck or van at a good distance from set and use a buck boost transformer to compensate for voltage drop (they are readily available from rental houses), with proper miking you should have no difficulty getting clean audio.

Peter Berger
 
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