102.9 Principles of Electricity

Rectifier

Changes alternating current to direct current

Inverter

Changes direct current to alternating current

Circuit

Closed path through which electrons travel to operate an appliance

Cord

Combination of conductor and insulator

Fuse

Contains fine metal wire that allows current to flow through it, if overload occurs, it will heat up and wire will melt, breaking the circuit. Cannot be reused.

Cord Safety

Cords on appliances should be kept straight and free of knots, kinks and tangles to prevent breaks

Short Circuit

Dropping an electrical appliance into water, making it a foreign conductor, causes a:

Open Circuit

Electron flow is broken

Alternating Current

Electrons flow first in one direction and then the other

Direct Current

Electrons move at an even rate in only one direction

Too many appliances use same wall socket (overload)

Fires in electrical circuits can occur if:

Battery

Has positive and negative terminals, produces direct current only

Conductor

Material that best transports electricity; safely contained in an insulator

Watt

Measure of energy (power) used per second

Overload

More current flows in the line than it is designed to carry

Electrons

Most of the electricity you use daily consists of a flow of tiny, negatively charged particles called:

Short Circuit

Occurs when a "foreign conductor" comes in contact with a wire carrying a current to a load (appliance)

Fire Extinguishers

P: Pull pin A: Aim hose at base of fire S: Squeeze handle to begin flow S: Spray chemical discharge back and forth over fire

Closed Circuit

Path of electron flow to an appliance

Generator

Power source most often used in salons, produces alternating current, uses mechanical energy to produce flow of electrons

Parallel Wiring

Powers several loads at once or at different times

Source

Provides the force to move electrons through a conductor (Generators and Batteries)

Ground Fault Circuit Interrupter (GFCI)

Recommended for areas where water and electricity could come in contact

Ohm

Resistance; measures how difficult it is to push electrons through a conductor

Circuit Breaker

Reusable safety device that breaks the flow of current when an overload occurs. Contains two pieces of metal that make contact with each other; the pieces of metal conduct electric current. If current flow is too high, heat-sensing device causes the two pieces of metal to separate and the circuit is broken.

Series Wiring

Runs all loads at the same time (Example: Xmas tree lights; if one string is malfunctioning the electrical circuit cannot flow to the next string, the malfunction causes an open circuit)

Two conditions necessary for an electric current:

Source and Circuit

Appliance Nameplate

Tells frequency, volts needed, watts appliance consumes per second and UL rating (Underwriters Laboratories)

Electric Current

The flow (or movement) of electric charge, the charge is carried by electrons

Closed Circuit

When a blow dryer is on and air begins to flow, you have an example of a:

Kilowatt

1,000 watts

Grounding

2-plug or prong system (two slots of different sizes that keep electric current directed), 3-plug or prong system (offers most protection)

Direct Current

A current in which electrons move at an even rate and flow in only one direction is known as a:

Insulator

A material that does not allow a current to pass through it

Electricity

A powerful and important form of energy that produces light, heat, magnetic and chemical changes

Loads

A technical name for any electrically powered appliance

Volt

Unit of electric pressure; measures how hard electrons are being pushed by the source

Amp

Unit of electric strength; indicates number of electrons flowing on a line

Put water on it

What should NOT be done if a fire results from an overload of an electrical circuit?

Overload

When too many appliances are put on one circuit and are operated at the same time, more current flows than the line is designed to carry. This is known as:

Circuit Breaker

Which device breaks the flow of current when an overload occurs?

Alcohol

Which material does NOT allow a current to pass through it?