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How to avoid tripping breakers

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joseph wilkins
How to avoid tripping breakers
on Jan 15, 2006 at 12:54:11 am

I am a one man band with a cheap Britek video lighting kit.

I usually use 4-5 lights - I think they are 1000 watts a piece.
I need to pre-empt this question by saying I know nothing about electricity, but think I need to learn fast!

I just bought a studio that runs on 220v. I want to know how I can avoid tripping breakers both in the field at peopples houses and offices and also at my studio

I would really appreciate as much info as possible


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john sharaf
Re: How to avoid tripping breakers
on Jan 15, 2006 at 1:25:47 am


If your new studio is wired for 220 volts it surely is not in the US! You are lucky though as 220v countries allow for more powerful lights to be used in typical household environments.

What you need to learn first about electricity is the simple formula that:

Watts = Amps x Volts

This way you can calculate that your 1000w lights at 220 volts use slightly less than 5 amps. Theoreticly you should be able to plug four of them into a twenty amp circuit. In the states, you can only plug two into a twenty amp circuit at 120v.

One way of course to keep from blowing fuses (or breaking breakers) is to relamp several of your instruments with 500w bubbles instead of 1K's. They could be used for the fill light or backlights, where you might otherwise be scriming or diffussing a 1K to create the proper lighting ratios. Alternately, you might replace (or add) several of your 1000w units with smaller ones like 200, 300 or 400w instruments for these purposes.

In your studio, if you own it, you might consider having an electrician install some extra circuits for your lighting needs. Perhaps here you might want to install a 2000 or 5000w light for special shoots and a dedicated receptical might be required.

On location of course one must always be concerned about blowing fuses; especially in an office where computers are working and a service interuption might cause loss of data. It's a good idea at all location shoots to warn the people there before you start lighting that there's always the chance your movie lights will overload a circuit so they are forewarmed and can at least save what they have done to that momoent and save more often than they might if you weren't there for the duration of your shoot.

It's also a good idea to query the occupants as to whether they know where the fusebox is; you'd be suprised how many folks don't have a clue in thus regard, and sometimes in offices they are locked up. If either of these is the case it's worth some effort to find the service and/or the key, before you blow the fuse, and if you can't you must be extra vigilent.

Having found the fuse box it's a good idea to open it up and gauge the size of the fuses/breakers. This will give you some guidance about how many lights (using your formula) that you can safely plug in. Also there is often nomenclature in the box that shows you how the circuits are divided in the house or office. Treat this information as a "guide" as it's often not correct or complete. The only way you'll ultimately find out is by blowing a fuse!

In the states, building codes require seperate circuits in bathrooms and kitchens. It's logical to assume that the service upstairs is different than downstairs, but this is not always the case, and many locations are wired in violation of code and logic. Having enough long extention cords is helpful in finding seperate circuits to bring to your set.

Nowadays most fuse boxes use cicuit breakers, but occasionally we still find in older homes and apartments the old style fuses. It's a good idea to carry a few spares of these types in your kit to cover the eventuality of your blowing an actual fuse and their nor being a spare. This way you won't leave the people who were nice enough to let you shoot in their home or office in the dark when you leave, making a return trip for you or another filmmaker more possible.

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joseph wilkins
Re: How to avoid tripping breakers
on Jan 16, 2006 at 1:14:24 am


Thanks so much for the detailed explanation - I really appreciate it! As always, the cow proves to be one of the best resources for tricky questions!


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