I am shooting a interview in a small office. i will be using a my DP3 Jr lighting kit (3000watts). I the past, it never fails; using this lighting kit pops breakers. How can I prevent this from occuring?
cinematography 3000 watts
- Thread starter wparrish24
- Start date
Change the lamps to a lower wattage or make sure you are on different circuits. I have a Lowel 2000 watt kit and frequently have to split the load with 15A circuits.
Boy, it's going to get hot in a small office with that wattage.
Yeah you need to pull from different breakers. An easy rule of thumb (for 120v AC) is 100w per amp is ok. A 20 amp breaker can pull 2000w ok. It can actually oull a bit more, but that's safe.
Bring long extension cords and run power from different rooms. Sometimes bedrooms and offices share breakers, but kitchens and bathrooms usually have their own since water is nearby, so try those if needed.
Another way to lower the wattage without changing bulbs is to use a dimmer. Each fixture should have one anyway since it really helps you shape the light. I built a few recently for cheap, bought the 1k dimmers on eBay for $18 each then another $10-12 each for wire, connectors and box.
Bring long extension cords and run power from different rooms. Sometimes bedrooms and offices share breakers, but kitchens and bathrooms usually have their own since water is nearby, so try those if needed.
Another way to lower the wattage without changing bulbs is to use a dimmer. Each fixture should have one anyway since it really helps you shape the light. I built a few recently for cheap, bought the 1k dimmers on eBay for $18 each then another $10-12 each for wire, connectors and box.
If you want to work with lights that powerful, then you need to learn some basic electrical principles. This isn't a dig at you, just common sense if you want to work safely and efficiently.
What concerns us here is the relationship between power (P, measured in watts), voltage (V, measured in volts) and current (I, measured in amps). In any electrical system, power (watts) is equal to the voltage multiplied by the current.
So: P = V * I
To work out which lights you can run on one circuit, we take its voltage (120V in the US, usually) and times by the rating of the fuse (15 amps, for example), leaving us with the wattage of lights you can use on one circuit. It's often simpler to use 100V instead of 120V in your calculations, as the mental maths is easier and it leaves you a safety margin.
If the above figures were correct, you would be able to safely run 1500W on one circuit - with a 300W safety margin. To use the other 1500W of lamps, you need to look at the breaker box and work out which rooms are on separate circuits, then run your other lights from another circuit and fuse. You have to be careful that no one turns on a kettle or a microwave or anything like that while your lights are on - it's all too easy to forget and trip the breakers.
So, to summarise: you can use smaller lights or multiple circuits, but before you do you need to understand what the limit is and why.
What concerns us here is the relationship between power (P, measured in watts), voltage (V, measured in volts) and current (I, measured in amps). In any electrical system, power (watts) is equal to the voltage multiplied by the current.
So: P = V * I
To work out which lights you can run on one circuit, we take its voltage (120V in the US, usually) and times by the rating of the fuse (15 amps, for example), leaving us with the wattage of lights you can use on one circuit. It's often simpler to use 100V instead of 120V in your calculations, as the mental maths is easier and it leaves you a safety margin.
If the above figures were correct, you would be able to safely run 1500W on one circuit - with a 300W safety margin. To use the other 1500W of lamps, you need to look at the breaker box and work out which rooms are on separate circuits, then run your other lights from another circuit and fuse. You have to be careful that no one turns on a kettle or a microwave or anything like that while your lights are on - it's all too easy to forget and trip the breakers.
So, to summarise: you can use smaller lights or multiple circuits, but before you do you need to understand what the limit is and why.
Here's the cheat sheet I use (US Power) on my sets for new folks... buy a tone generator at home depot/ lowes for electrical outlets that will allow you to trace the outlets you're using back to the panel and Identify the circuit they're on. This will allow you to determine how many amps you have to work with on each circuit (remember any existing devices on any circuit use up some of the available amperage).
In general, for 110/120 power, just take the wattage of the light you're using and divide by 100 to find the amperage of the light with a safety margin for surges and powerup. I've never blown a fuse or tripped a breaker on set using this sheet
If I don't know the circuits, I pull from the opposite side of the structure using REALLY long extension cords to make sure I'm on a separate circuit to have 2 circuits available... and I never load more than 1500watts on a single circuit.
(3 x 500w)
(2 x 650w)
(1 x 500w, 1 x 1k)
Hope this info serves you well.
View attachment amp cheat sheet.pdf
In general, for 110/120 power, just take the wattage of the light you're using and divide by 100 to find the amperage of the light with a safety margin for surges and powerup. I've never blown a fuse or tripped a breaker on set using this sheet
If I don't know the circuits, I pull from the opposite side of the structure using REALLY long extension cords to make sure I'm on a separate circuit to have 2 circuits available... and I never load more than 1500watts on a single circuit.
(3 x 500w)
(2 x 650w)
(1 x 500w, 1 x 1k)
Hope this info serves you well.
View attachment amp cheat sheet.pdf
1500w per circuit leaves a wide safety margin, but a 15A circuit is technically rated for 1875w, and I powered my Mole 2K for days with nary a popped breaker, fwiw.
Alot of the locations I've been on have said they have nothing else running on a circuit, but a closer inspection shows they're not telling the truth (because they don't know)... I account for that in my calculations.
Ah, yes, I can totally see that! For big shoots I don't even ask; just assume that the owner has no idea what a "circuit" is, much less the amperage being drawn on it, and figure it out for myself.
Last shoot the location had a deep freezer on 220. Fortunately it was empty, so we tore apart the 220 socket and wired in two temporary 110's. What they didn't know didn't hurt them.
I was on an indie shoot once in Seattle that was using an old, wooden warehouse as a soundstage. The building wiring was iffy at best and they needed to power a 5K, so the gaffer wired in a 220 and several 110's from the building's main service feed. He was my hero!
...the gaffer wired in a 220 and several 110's from the building's main service feed. He was my hero!
I'm going to point out that he's probably a licensed electrician as well so folks don't go seeing if they can get the breaker box in their next shoot to throw them across the room while stopping their heart and "killing" (pun intended) any chances of them finishing their film.
You can DIY a dimmer box out of a standard dimmer you mount on a wall for about $20 as well.
My last film was shot in a 12 X 15 rooom, at some points there was about 3300 watts of light in use.
My last film was shot in a 12 X 15 rooom, at some points there was about 3300 watts of light in use.
Keep in mind, 1000 watt lights need AT LEAST a 1000 watt dimmer. The cheap household ones are only rated for 600w. At home depot, 1000w dimmers run around $50. Try eBay if you want to get it closer to $20-30.
Also, use good wire. Preferably 12 gauge, 14 should be ok.
Also, use good wire. Preferably 12 gauge, 14 should be ok.