Portable Generators

evil_edison

evil_edison

Active member
Hi all. Sorry in advance if this is a dumb question but I was wondering if anyone had ever used one of those portable generators (the kind you get from Lowe's or Home Depot) with their lighting equipment. I have a 2K light which I can't use on most household circuits (15 amp breakers) but I noticed that some of these generators (which are down around $500) are equiped with 20amp circuits. I'm tempted to pick one up but I'm wondering if there are any problems with power fluctuations or things of that nature. If anyone's had any experience with these please let me know.

Thanks,
Sean
 
Re: Portable Generators

I think I've heard before that they are not a good idea. Someone else could probably give you better insight on that. My big concern would be the noise level that you would pick up on the mic. Because those things are LOUD.
 
Re: Portable Generators

I'm no generator expert, but it's my understanding that the quality of the power coming out of the generator may not be as "clean" as you'd like. I believe DC Inverter generators may be the cleanest, delivering a real sine wave. I wouldn't expect the lower-cost generators to be overly clean in their power delivery; a circular saw or other power tool is probably a lot less picky about the quality of its AC than a camera or monitor or lighting instrument. But hey, it might work...
 
Re: Portable Generators

Also, lower quality gennys aren't as likely to deliver a steady voltage, which could lead to your lights changing color and intensity during shooting.

A 2k lamp is going to pull close to 20 amps, and even if a generator has a 20 amp circuit interrupt, there's no guarantee that it can deliver 20 amps, or even deliver 20 amps consistently.

You're asking a lighting question that really falls into the realm of a professional gaffer. The best way to accomplish any sort of location lighting using house power is to tap into the breakerbox at the mains and run two separate single phase feeders to distro boxes. This is the safest way to light using AC current on a location because you're skipping all the house wiring. Let me tell you from experience, there's nothing more sobering then having a house full of stingers plugged into wall outlets in different rooms and then suddenly smell something burning. By tapping into the mains above the individual circuits, you reduce your risk of overloading the house's electric, and because the house electric is inside the walls, there's no way of verifying the quality of materials, and when those materials overload and start to burn...you're in serious trouble, as they're buried inside walls full of dry fuel.

Now, with all that being said, I can't stress enough how much you SHOULD NOT EVER TRY TO TAP INTO A BREAKER BOX.

Besides being incredibly dangerous, it's probably illegal in your location and should only be done by a licensed electrician. You're going to be dealing with twin 100amp circuits in most cases, and if you don't know what that means exactly...INSTANT DEATH comes to mind. Even if you're experienced in doing this (which I am to some degree), ANYTHING can go wrong when you're tapping in or out.

I was standing at the top of the basement steps on one shoot, waiting for the gaffer and AD to finish tapping in when there was a huge blue flash in the basement. It took a few minutes before we were sure everyone was okay, but it turned out that one of the main 100 amp circuits blew up while they were pushing one of the legs in the terminal. The best that we could guess was that it was just an old breaker. It was replaced professionally (at cost to the producer), and shooting was delayed a day.

My point being that electricity is dangerous, and more so...using large lights carries a certain amount of danger (not just a risk of death and injury, but also of serious damage to property).

The average house can handle 1k's well, especially if you're aware enough to space out the load, but getting into the 2k and up range, you need to be very aware of what you're doing to the house electrically. The best thing to do would be to see if you can call in a favor from a licensed electrician to poke around your electric and give you a good idea of where you can safely and reliably attach a 20 amp draw to your electric. A lot of household clothes dryers (if they're electric) are on their own 20+ amp circuit. Most of the time it's going to be a 220 three phase circuit, but you might get lucky and find a single phase 110 in your house you can draw off of.

Open up your breaker box and see what you’ve got in there. If everything’s 15 amp, then you might not want to attach a 2k light…your wiring might not be solid enough to handle it, but it’s more likely that you’ll find a few 30 amp circuits in there. If you can find where those go, you can attach your 2k on to one of those.

But again, don’t take anyone’s advice when it comes to electricity (unless they’re telling you NOT to do something). Electricians are licensed for a reason.

Be safe, be careful, and good luck.
 
Re: Portable Generators

Wow. Talk about having the fear of God instilled in ya! :) I think I'll just stick with the lower wattage bulbs for now. I was definitely concerned about possible fluctuation in the generators and I agree that's probably the case. I would NEVER go poking around in a household electrical box. Yikes! Actually had a pretty scary lighting moment last week. We were shooting inside with an outside light shining in through the window. Part way through the shot the camera guy looks up and says "Why is the light flickering?". We looked out and saw it was POURING RAIN!! I will say I was pretty impressed with the light though (a Lowel DP). Apparently it was water proof :) Didn't go out in a torrential downpour and after we dried it off it worked fine for the rest of the night.
 
Re: Portable Generators

Fear of god, hell yeah. If people use copywritten materials in their films, they might get sued...but if people use non-experienced gaffers on their shoot, they might get dead. You can only recover from one of those two.

In the future, when dealing with rain, you want to look into getting something called "Rain Hat".

Rain Hat is a fine meshed metal screen type material that is usually cut into sheets somewhere around 3' x 4'. It's stiff, but flexible and you bend it into a horseshoe shape and clip it above your light so that it's acting like a little umbrella.

Rain hat will keep most downward rain from hitting the light, and it transfers it down the sides of the material rather then through the mesh. It won't really help that much in driving rain.

Also, to be extra safe when shooting in inclimate weather, tape up all of your connections with electrical tape...very tight. Then if you want added security, tape a sheet of plastic around the connections and elevate them so they don't fall into puddles.

Using rain hat and taping all your connections well will make shooting in the rain pretty safe. Lights are relatively durable and should be able to operate well under mild rainfall as long as you take precautions.

When it's below freezing, you can have problems with lenses and bulbs shattering, but that's another story entirely.
 
Re: Portable Generators

J_Barnes lecture on electricity should be heeded by all.

It's another reason why I despise tungsten lighting, it's so power-hungry and inefficient.  Fluorescents whenever possible... you can hook up eight Kino Flo Diva 400 lights to one household circuit (giving you about 7,000 watts worth of soft light), but only one 2K tungsten light on a circuit before you're in trouble.  That's another reason the Britek Dayphoto's are so interesting: you get about 1200 watts of light out of them (and if you were trying to match their blue look with tungsten you'd need almost 5,000 watts of tungsten light to match one DayPhoto!)  but you can hook up three or four DayPhotos to a single household circuit.  Using fluorescents and HMI's can minimize or even eliminate fretting about circuitry and wiring and amps and breakers.
 
Re: Portable Generators

What's the pricetag on these DayPhotos? And are they hard or soft light? And yes, I agree, JBarnes lecture is well received. Like my grandma used to say "Better safe than six feet under". Actually... she never said that, but I'm sure she'd agree. :)
 
Re: Portable Generators

DayPhoto's are low-cost HMI units. They're open-faced hard lights with barn doors that also include softboxes with them, so depending on how you configure it they could be hard or soft light. The price is $995 but they've been discontinued. Currently there's some people trying to convince Britek to start manufacturing again, they'd need a few hundred interested buyers before it was worth it to 'em to fire up the manufacturing lines again.
 
Re: Portable Generators

[quote author=Barry_Green link=board=lighting;num=1093574888;start=0#6 date=08/27/04 at 11:40:36]J_Barnes lecture on electricity should be heeded by all.

It's another reason why I despise tungsten lighting, it's so power-hungry and inefficient.  Fluorescents whenever possible... you can hook up eight Kino Flo Diva 400 lights to one household circuit (giving you about 7,000 watts worth of soft light), but only one 2K tungsten light on a circuit before you're in trouble.  That's another reason the Britek Dayphoto's are so interesting: you get about 1200 watts of light out of them (and if you were trying to match their blue look with tungsten you'd need almost 5,000 watts of tungsten light to match one DayPhoto!)  but you can hook up three or four DayPhotos to a single household circuit.  Using fluorescents and HMI's can minimize or even eliminate fretting about circuitry and wiring and amps and breakers.[/quote]


The only thing that sucks about Kino's is:

a) They're weak unless you start combining two or three of them and who wants to haul all that around
b) They're big compared to say a Lowel Rifa-Lite
c) They're expensive
d) They're really not THAT light. Check out the weight on some of those models on the Kino Flo website.
e) I don't see how you can put these lights a few feet above eye level and aim them down.

I think I'd probably go for a Lowel Caselite before a Kino because they are more efficient due to the mirror barndoors. A Caselite 4 with the intensifier barndoors has a little more output than my Rifalite 88.
 
Re: Portable Generators

Actually, as the caselite and it’s closest cousin, the kinoflo Diva weigh almost exactly the same. 14.2 lbs for the caselite4, 14 for the diva 400, so weight isn’t an issue between them. Furthermore, the kino 4’ 4bank system is more often used then the diva, and because it’s a separate ballast/lamp system…the head with all it’s components weighs about 10 lbs on a stand versus the caselite’s stand weight of 14 lbs.

As far as light output, lowel doesn’t publish volumetric data for these lights. Kino does, and from my experience…I didn’t find the mirrored barndoors to increase the output of the caselite over the kinos.

You can say kino’s are big compared to a rifa light, but they’re completely different types of light. Kinos are long and flat with a huge surface of light, rifas are deep chimera style lights with a smaller luminous area. Because of their depth, chimeras defiantly take up more airspace on set while providing a smaller projection of light.

Also, softbox lights are inherently inefficient, as they require so much more wattage to blast through the diffusion compared to an already diffuse light source. At 6’ a kino select 4 bank is putting out 70 fc’s of soft light…but it’s also only consuming 3.5-5amps versus any 1k light through a soft (close to 10 amps).

Last but not least, any lighting tech worth his salt can put a kino anywhere you want it to be. Being so light weight, they’re almost infinitely position able. If you somehow find a position that a stand can’t get to, you can always pop the lamps out of the housing and tape them where you need them to be. Try doing that with a rifa, or any softbox.

Kinos, or any soft source for that matter, shouldn’t be the primary light in a kit. They’re great close source keys, fills, and accent lights…but they’re not designed to cover all bases. And if you spend the extra money, you know you’re going to have a very durable workhorse.

Lowel makes nice stuff for lightweight production, but there’s a reason you don’t see a lot of lowel equipment on professional productions.
 
Re: Portable Generators

also, this isn't knocking the rifa...just pointing out that they're different lights with slightly different uses.
 
Re: Portable Generators

As for generator usage. Incandescent lighting does not suffer, per se, from use with generators. They won't blow up or flicker. But they will draw down the voltage if there isn't enough reserve power to properly run the gen with your draw. What that means is that if you want to run a 2K use a 3500w generator or higher. The reserve will keep the voltage up to acceptable levels and thus keep your color temp close. With the 2k generator you mention, I wouldn't put more than about 1000w draw on it. Incandescant bulbs will work fine with lower voltage but will have major changes in the color temp.
I did a show for a plumbing manufacturer at a site with no power. We rented an 8k generator from a rental place and ran about 5k worth of lights with no problems. No sound recording. The bigger the generator, the less of a safety margin you'll need.
As for the 15 amp circuits and the 2k. Look around the house, there's usually one or two 20 amp circuits. Try the kitchen and the bath. Make sure there's nothing else on the circuit. A 2k draws about 17 amps.
 
Re: Portable Generators

Thanks Xort. I think I'll see if Home Depot will rent one of these generators so I can try it out. Sound will definitely be a consideration. Does anyone know of a brand of generator that is a little quieter?
 
Re: Portable Generators

motion picture grip and lighting rental houses usually carry large 'blimped' generators. They are not silent but extremely quiet for the power they put out. We're talking 20,000w and up. They have a chrystal control to keep the power at 60 hz.
Rent for $350/day and up, need to be towed by full size truck.
Many folks have built sound boxes for the smaller generators. There are some big differences in sound level between generators. Some are pretty quiet and some are extremely loud. The quieter ones can be helped by several things. 1st is distance. Get it far away. Second, put it behind a building so the building acts as a big block. Third, aim the exhaust away and fourth, build a box around it with plywood and maybe furniture pads. Be VERY careful with this step. You must provide ventilation for the generator to prevent overheating and you must keep the wood and pads from catching fire!
 
Re: Portable Generators

> If anyone's had any experience with these please let me know. <

Yes, I have. I ended up with the newest, Honda generator. (I forget the model, but they sell 'em at camper places.)

They have the lowest noise level.Made to not annoy folks at camping sites. However, you still need your extension cords to be really long and to get that sucker way out of ear shot.

I have to do some night stuff soon and I'm going to build a little box with some acoustic tile inside to buffer even more.

Nice thing is that it will run 3 650 k frenels. That is as far as I have pushed it though.
 
Re: Portable Generators

For your 3 650's, How long did you have them on using that generator? How much gas does one of those generators take? What is the max limit of wattage you can or should run using a portable generator? Right now I just own a Arri 1K but I am planning on getting more lights soon.
 
You must log in or register to reply here.
Back
Top