Basic Electricity

Basic Electrical Circuit + Pos Electromotive Force Neg - Voltage is applied to a circuit or load. It is present and does not flow. Voltage transfers along a conductor. Current flows through a conductor. The same amount flows throughout. Current is not lost. Whatever leaves the source must return to the source. = Electrons = Conductor Resistance Load

Basic Electric Safety Electrical Fire Burns Do not use water or touch the burning object. Why? ______________________________________ If possible, disconnect or turn off the power. Use an ABC Fire extinguisher and notify the Fire Department. Call 911. Burns For a serious burn, seek immediate medical attention. Call 911. 1st degree burn – red inflamed 2nd degree burn - Blistering 3rd degree burn - Charred

Lockout Devices Lockout devices are commonly used on circuit breaker panels, switches, and disconnects. They should be brightly colored and easily visible. The following are typical devices: 1. A circuit breaker lockout 2. A padlock 3. A lockout for an electrical cord

Types of Circuits Series circuit: Voltage drops but amperage stays the same. Parallel circuit: Amperage drops but voltage stays the same.

Illustration of Ohm’s Law E R I P E (Voltage) = ______________ X ______________ I (Current) = ______________ X ______________ R (Resistance) = ______________ X ______________ P (Power) = ______________ X ______________ Volts Amps Ohms Watts

Test Breaker Illustration How many volts does a single pole breaker supply? _______________________________ Why? _______________________________ How many volts does a double pole breaker supply? ____________________________ Why? ______________________________ What are two ways to test a circuit breaker? ___________and ____________ So, continuity means the breaker is _______ If a double pole breaker has 120 to ground on each leg but when measured together reads zero is the breaker good or bad? ___________ 120 It only touches one Bus Bar 240 It Touches Two Bus Bars Voltage Continuity Good   Bad

Types of Wires Decreases Single A wire is a _________ conductive strand Cable contains __________strands of wire Multiple Wire ampacity must be matched to the specific load of its circuit. Why is it important to use the correct size wire? _____________________________ Why must aluminum wire only use devices labeled CU/AL or CO/ALR? As the gauge increases the actual size of the wire _______________? Decreases Wire Size Amp Rating Breaker Size Voltage #6 60 65 240 #8 40 45 #10 30 #12 20 120 #14 15 #16 Light Extension Cord #18-22 T-stats Doorbells

Types of Switches The purpose of a switch is to complete or break a desired path in a circuit. Most switches used in residential applications are toggle switches. By far the most common is the single pole switch. It usually breaks an incoming hot wire that is connected to one screw. The three-way switch has three terminals and is used to control a circuit from two locations. One terminal is marked COM or COMMON and that terminal is attached to the hot wire. The other two terminals are switch leads. The double pole switch is typically used with 240 volts. EVERYTHING you need to know is already on the switch! UL means underwriters laboratory. A/C means it will only handle A/C. CO/ALR for used with aluminum or copper. 15a-120v it is rated for 15 amps and 120 V.