Electricity Cheat Sheet-Virtual PDF

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Electricity Cheat Sheet-Virtual， this is for film and tv production crouse...

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PRODUCTION SAFETY AND SET PROTOCOL ELECTRICITY AND ELECTRICAL DISTRIBUTION CHEATSHEET Review Ohm’s Law and how it applies to extension cords.  

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Amps (I) = Volts (V)/Ohms (R-resistance) Compare this to a garden hose: Amps (is the amount of water coming out of the garden hose. Volts is the water pressure pushing the water through the hose. Ohms is the length of the hose and the size of the hole in the hose. The longer the hose, the more resistance. The smaller the hole in the hose, the more resistance. Do not plug one extension cord into another unless they are rated for such use.

Proper Grounding.   

Use a ground tester to check an outlet. Any light over 100 watts must be grounded. If an outlet does not have a ground receptacle, use a 3 to 2 adaptor and connect the green ground wire (or horseshoe clip) to the small screw holding on the faceplate. Never modify or remove a grounding connector (the third prong) of a plug. Check with the ground tester.

Polarity. 

Proper polarity means that the on/off switch of a light fixture or electrical appliance is on the hot wire (black), not on the neutral wire (white). When the switch is off and polarity is correct, electricity will not be present at the fixture or appliance.

Electrical Distribution in a Practical Location, where the power being supplied is coming from the normal household circuits.    

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Be sure to bring the gaffer (electrician) to the tech scout before production starts. The first thing that the electrician will do is locate the circuit breaker (or fuse) box. Open the box and determine if it is circuit breakers or fuses. If it is circuit breakers, only breakers rated with either 15 amps or 20 amps will be used (those numbers will appear on the circuit breaker switch). All other circuit breakers are for dedicated circuits for central air conditioners, freezers, and etc. Check to be sure no computers without battery backups or life support systems are on those 15 or 20 amp circuits. Turn off all 15 and 20 amp circuits, and then turn one number 1 circuit. If it is not labeled, take a piece of tape and label it #1. Try to turn light switches on. If

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they come on, that is on circuit #1. Label it #1. Check the outlets with a ground tester. If it comes on, that is circuit #1. Label it #1. Turn on switch #2 and repeat the process. And #3 and #4 and so on until you have determined where all of the circuits are. If the circuit box has fuses, use the same process to determine the circuits. Only use 15 or 20 amp circuits. If you find that there is a 25 amp fuse on a circuit that you can access, do not trust it and do not overload it. No more than 20 amps allowed on any circuit you can access. Use the following formula to determine the maximum load allowed on any circuit: Amps (I) = Watts (W)/ Volts (V). 100 W/120 V = .83 Amps. We use “Paper” amps to make the math easier and for additional safety, because we burn our lights all day long on a film set, and the wires continue to heat up. 100 W/100 V = 1 “Paper” Amp. 500 W = 5 Amps, 1000 W = 10 Amps, and so on. Do not overload any circuit and only an electrician is allowed to plug anything in on a film set, not the wardrobe person, hair and make-up, or production management staff.

Ad di t i o n a ln o t e s .  

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