1. Every electrical system must have three parts, a source, a load, and a circuit.  Source - the origin of electrical potential, such as a battery or 120 volt wall outlet  Load – A device that converts electrical energy into another form of energy. (Ex lamp to light)  Circuit – A conductive path through which electricity flows

2. Definitions Ampere (Amps) – the flow of electrons from on point to another Volts – The units of measurement of electrical potential. Watts – the measurement of the amount of electrical energy converted or consumed. Ohms Law – As voltage increases, current increases; as resistance increases, current decreases.

3. The following power formula is used to find amps, watts, or volts as long as at least two of the three are present. (West Virginia) Watts = Volts times Amps(W= VA) Amps = Watts divided by Volts(A=W/V) Volts = Watts divided by Amps(V=W/A)

4. Example: Desk Lamp on a table carries 6 amps of current Standard U.S. household socket is 120 volts The lamp is 150 Watts Is it safe?

5. Electrical Wires and cables are designed to carry specific current loads. Wires are classified by their gauge. (Thickness of wire) Gauge 1012141618 Amps25201563

6. Safety Features Electrical systems are designed to work with in certain limits. If those safe limits are exceeded, then one of two things will happen.  If protective devices (fuses, circuit breakers) are intact they will break the continuity of the circuit and break the flow of electricity  Items involved will either heat up to the point where they will either melt or burn up. Or if they are combustible, a fire could start.

7. Problem #1 Voltage of dimmer = 120 Amps per circuit = 20 How many watts ?

8. Problem #2 Voltage = 120 Amps = 15 How many 500 watt instrument can be loaded?

9. Three Types of Circuits  Series – One doesn’t work none work  Parallel – One can be out others will still work  Combination – Any electrical circuit that uses a switch to control a light, however the circuit is set up as a parallel circuit

10. How to connect a wire to a connector  Black to Brass = Hot  White to Silver = Neutral  Green to Green (Ground) = Ground