Basic Electrical WiringBasic Electrical Wiring

Grimsby SecondaryGrimsby Secondary SchoolSchool

Electrical SafetyElectrical Safety"Shocking Statistics“"Shocking Statistics“

There are approximately 290 accidental electrocutions each year. There are approximately 290 accidental electrocutions each year.

An additional 800 people die in fires caused by faulty electrical An additional 800 people die in fires caused by faulty electrical systems every year. systems every year.

Thousands are shocked and burned as the result of accidental Thousands are shocked and burned as the result of accidental contact with electricity every year. contact with electricity every year.

An estimated $1.2 billion in property damage occurs each year due An estimated $1.2 billion in property damage occurs each year due to faulty use of electricity.to faulty use of electricity.

ElectricityElectricity

Electricity is the flow of electrons in a Electricity is the flow of electrons in a conductor. conductor.

The electrons must have a path to and The electrons must have a path to and from its source. from its source.

This path is called a circuit.This path is called a circuit.

ElectricityElectricity

Various electrical devices are used as a Various electrical devices are used as a part of the circuit. part of the circuit.

These devices are used for a variety of These devices are used for a variety of activities, such as turning the electricity off activities, such as turning the electricity off and on, providing electricity to various and on, providing electricity to various lights or appliances, etc.lights or appliances, etc.

Types of Electrical CurrentsTypes of Electrical Currents

Electrical current comes in two forms:Electrical current comes in two forms:– Direct current (DC)Direct current (DC)

Flows in only one direction. Flows in only one direction. It is usually generated by battery-base electrical It is usually generated by battery-base electrical systems and used in the electrical systems of systems and used in the electrical systems of internal combustion engines or flashlight batteries.internal combustion engines or flashlight batteries.

– Alternating current (AC)Alternating current (AC)Reverses the direction of flow of current many Reverses the direction of flow of current many times each second. times each second. AC is the type used in homes, factories, etc.AC is the type used in homes, factories, etc.

Electrical ServiceElectrical Service Service is provided to homes, businesses Service is provided to homes, businesses

and other small users of electricity by and other small users of electricity by three wires from a utility pole. three wires from a utility pole.

Two of the wires are “hot,” each carrying Two of the wires are “hot,” each carrying 120 volts. 120 volts.

The other wire is “neutral,” and provides The other wire is “neutral,” and provides the return path for electricity. the return path for electricity.

Electrical Service (cont.)Electrical Service (cont.)

These wires are connected to a service These wires are connected to a service entrance, which is where the electricity entrance, which is where the electricity enters a building. enters a building.

A meter is used in the service entrance to A meter is used in the service entrance to measure the amount of electricity being measure the amount of electricity being used.used.

Electrical Service (cont.)Electrical Service (cont.)

The service entrance is grounded with a The service entrance is grounded with a wire connected to a ground rod driven wire connected to a ground rod driven several feet into the ground. several feet into the ground.

It is needed to provide a return path to the It is needed to provide a return path to the ground and to carry away stray electrical ground and to carry away stray electrical current out of the system. current out of the system.

Service PanelService Panel Follows the meter. Follows the meter.

It houses the circuit It houses the circuit breakers for the breakers for the system and is used to system and is used to distribute the power to distribute the power to individual circuits individual circuits throughout the throughout the system.system.

OvercurrentOvercurrent When a circuit uses too much electricity, an When a circuit uses too much electricity, an

overcurrent causes a circuit breaker to trip, overcurrent causes a circuit breaker to trip, shutting down the power to that circuit.shutting down the power to that circuit.

The excessive heat caused by an overcurrent The excessive heat caused by an overcurrent condition may burn or damage a conductor’s condition may burn or damage a conductor’s insulation and cause a fire. insulation and cause a fire.

A circuit breaker is a heat-sensitive switch, A circuit breaker is a heat-sensitive switch, which automatically trips when electricity which automatically trips when electricity demand is too great which causes the demand is too great which causes the temperature in the conductor to get too hot. temperature in the conductor to get too hot.

Amps Volts WattsAmps Volts WattsThe following relationship exists The following relationship exists between between Amps, VoltsAmps, Volts and and WattsWatts..

Amperes are a measure of the rate of flow of electricity in a conductor.

Volts are a measure of electrical pressure.

Watts are a measure of the amount of energy or work that can be done by amperes and volts.

What symbols are used in drawing various What symbols are used in drawing various electrical devices?electrical devices?

In order to successfully draw a wiring circuit In order to successfully draw a wiring circuit on paper, one needs to use various symbols on paper, one needs to use various symbols that represent the equipment.that represent the equipment.

Identify and draw various symbols used in drawing wiring diagrams or

schematics.

Cable TypesCable Types

Cable TypesCable Types

One is 14/2 with ground, which has one One is 14/2 with ground, which has one black conductor, one white conductor, and black conductor, one white conductor, and a bare ground conductor. a bare ground conductor.

Cable Types (cont.)Cable Types (cont.)

A third type of cable is 14/3 with ground, A third type of cable is 14/3 with ground, which has one black conductor, one white which has one black conductor, one white conductor, one red conductor, and one conductor, one red conductor, and one bare ground conductor.bare ground conductor.

Additional symbols are used Additional symbols are used to identify terminals and to identify terminals and

indicate if wires are spliced or indicate if wires are spliced or just crossing over. just crossing over.

Symbols (cont.)Symbols (cont.)

Symbols (cont.)Symbols (cont.)

MARRETTE External cap made of tough, durable polypropylene. Threaded entry helps guide large wire bundles into the spring chamber. Unique copper-coated spring helps resist corrosion. Approved for circuits up to 600 V, and lighting fixtures and sings up to 1,000 V.

DiagrammingDiagramming

Generally, black and red conductors Generally, black and red conductors carry “hot” power or current from the carry “hot” power or current from the source to the devices within the source to the devices within the circuit. circuit.

The white conductor is always used to The white conductor is always used to carry the current back to the source.carry the current back to the source.

Two and Three wireTwo and Three wire

How to wire a receptacleHow to wire a receptacleAll receptacles should be wired such that the hot or live (black) lead is connected to a specific side of the outlet, and the neutral (white) lead to the other.