Rule of thumb for Max's of 20a, 60a, 100a, Edisons.

sheeep

Active member
Anyone have a formula or rule of thumb of just how much can get plugged into what? If you want to accompany your answer with a physics-degree level explanation too please do.

I heard from a studio guy that any combination 2k+ should go on a 60a line, so 20a can take up to 2000w. I'm sure that varies on the lights, etc.
 
well if you are talking about how much before you blow a circuit, for every 1000w you are using 8.3amps, so most people just say paper amps, which is rounding up so it'd be 10amps

Most houses are 15 or 20 amp circuits, so you can get about 2 - 1k's max before you trip the breaker.

if you have cables and stingers with max amps, (all do) then you can follow the same rule, otherwise you can over heat the cables and they'll melt, catch fire, short out, kill someone, or all of the above.

simple way at looking at it, takes the wattage, divide by 100, and thats your amps

hope that helps.
 
I might add that when you max out a breaker it heats and will trip and the more often you max it the more often it will trip. Best rule along with Nomadic`s math is bring lots of stingers and spread it around if shooting in a house. If shooting in an office , buy the building maintenance person a coffee, find the breaker panel and do the same thing spread it around, No one will be happy with you if their PC goes down because your two Totas tripped the breaker. IF the situation calls for that much light, building your budget to allow for a pro to do a tie-in from the box with proper cable etc. is worth it.
Or,
use more effecient higher output per amp instruments, like hmi lights or kino style or quartz hallogen.
Brian
 
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and use heavy duty stingers (14 gage or better). Smaller wires heat up faster, and therefore use even more current, then NOMADIC disaster (see above).
 
........
simple way at looking at it, takes the wattage, divide by 100, and thats your amps
hope that helps.

That's the easiest to remember. Also the safest way to look at it because your actual current draw (from a 120v circuit) will be a few amps less leaving you a little room for voltage spikes, i .e. switching stuff on/off.

Oh yeah, and as Dick mentioned "14 gage or better" meaning a smaller number like "12". Smaller number = bigger wire.
 
I made my own 10 gauge stingers. They are the most macho stingers I have seen short of banded, they are huge. Problem is a crate of them in 25' and 50' gives you a hernia to lift. But great for my Mighty.

Dan
 
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