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Fundamentals of Electricity. Or…how to wire a plug without electrocuting yourself or half a dozen of your co-workers!. Electromotive Force (EMF). Measured in: Voltage (E) Amperage (I…for inductance) And Resistance (R). Electromotive Force (EMF). Voltage or Electromotive Force
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Fundamentals of Electricity Or…how to wire a plug without electrocuting yourself or half a dozen of your co-workers!
Electromotive Force (EMF) • Measured in: Voltage (E) • Amperage (I…for inductance) • And Resistance (R)
Electromotive Force (EMF) • Voltage or Electromotive Force • Measurement of potential at any point in a circuit • Another way to understand it is as pressure. • Measured in Volts
Electromotive Force (EMF) • Amperage or Inductance • Measurement of the flow of current through a circuit at any given point. • Sort of like volume or flow of water through a pipe. • Measured in Amps • Inductance is the generation of an electromagnetic field by the flow of electricity through a wire or coil of wire.
Electromotive Force (EMF) • Resistance • Resistance to the flow of electricity at any given point in a circuit. • Measured in ohms. • Ohm’s Law: As Voltage increases, Current increases; As Resistance increases, Current decreases.
Electromotive Force (EMF) • The formula: E=IR where E=voltage, I=current, and R=resistance. • Other configurations include I=E/R, and R=E/I • An easy way to remember is “Eagle, Indian, and Rock.”
The Power Formula, W=VA • Used to calculate (based on two knowns) • Wattage consumption • Current • Or Voltage • Easiest way to remember as the “West Virginia Law.” • Other configurations include: A=W/V, and V=W/A
Wire Gauge • Standard sizes specified by the National Electrical Code (NEC) • Larger the number the smaller the diameter of the wire. • Gauge 10 12 14 16 18 Amps 25 20 15 6 3
Electrical Circuit Types • Series Circuit: Voltage is shared equally with each load in the circuit. • Parallel Circuit: Amperage is shared equally with each load in the circuit. • A “LOAD” is any element within a circuit that resists –but does not halt- the flow of current (lamp, motor, or resistor, etc.)
Electrical Current • Direct Current • Electron flow is in one direction and at a constant rate • Alternating Current • Electron flow changes direction (polarity) in regular, repeated cycles.