Electrical Wiring
Content
Basic Electrical Wiring
Electrical Safety
"Shocking Statistics“
There are approximately 290 accidental electrocutions each year.
An additional 800 people die in fires caused by faulty electrical
systems every year.
Thousands are shocked and burned as the result of accidental
contact with electricity every year.
An estimated $1.2 billion in property damage occurs each year due
to faulty use of electricity.
Electricity
Electricity is the flow of electrons in a
conductor.
The electrons must have a path to and
from its source.
This path is called a circuit.
Electricity
Various electrical devices are used as a
part of the circuit.
These devices are used for a variety of
activities, such as turning the electricity off
and on, providing electricity to various
lights or appliances, etc.
Types of Electrical Currents
Electrical current comes in two forms:
– Direct current (DC)
Flows in only one direction.
It is usually generated by battery-base electrical
systems and used in the electrical systems of
internal combustion engines or flashlight batteries.
– Alternating current (AC)
Reverses the direction of flow of current many
times each second.
AC is the type used in homes, factories, etc.
Service Panel
Follows the meter.
It houses the circuit
breakers for the
system and is used to
distribute the power to
individual circuits
throughout the
system.
Overcurrent
When a circuit uses too much electricity, an
overcurrent causes a circuit breaker to trip,
shutting down the power to that circuit.
The excessive heat caused by an overcurrent
condition may burn or damage a conductor’s
insulation and cause a fire.
A circuit breaker is a heat-sensitive switch, which
automatically trips when electricity demand is
too great which causes the temperature in the
conductor to get too hot.
Amps Volts Watts
The following relationship exists
between Amps, Volts and Watts.
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.
Identify and draw various symbols
used in drawing wiring diagrams or
schematics.
What symbols are used in drawing various
electrical devices?
In order to successfully draw a wiring circuit
on paper, one needs to use various symbols
that represent the equipment.
Cable Types
Cable Types
One is 14/2 with ground, which has one
black conductor, one white conductor, and
a bare ground conductor.
Cable Types (cont.)
A third type of cable is 14/3 with ground,
which has one black conductor, one white
conductor, one red conductor, and one
bare ground conductor.
Additional symbols are used
to identify terminals and
indicate if wires are spliced or
just crossing over.
Symbols (cont.)
Diagramming
Generally, black and red conductors
carry “hot” power or current from the
source to the devices within the
circuit.
The white conductor is always used to
carry the current back to the source.
Two and Three wire
How to wire a receptacle
All 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.
Electrical Safety
"Shocking Statistics“
There are approximately 290 accidental electrocutions each year.
An additional 800 people die in fires caused by faulty electrical
systems every year.
Thousands are shocked and burned as the result of accidental
contact with electricity every year.
An estimated $1.2 billion in property damage occurs each year due
to faulty use of electricity.
Electricity
Electricity is the flow of electrons in a
conductor.
The electrons must have a path to and
from its source.
This path is called a circuit.
Electricity
Various electrical devices are used as a
part of the circuit.
These devices are used for a variety of
activities, such as turning the electricity off
and on, providing electricity to various
lights or appliances, etc.
Types of Electrical Currents
Electrical current comes in two forms:
– Direct current (DC)
Flows in only one direction.
It is usually generated by battery-base electrical
systems and used in the electrical systems of
internal combustion engines or flashlight batteries.
– Alternating current (AC)
Reverses the direction of flow of current many
times each second.
AC is the type used in homes, factories, etc.
Service Panel
Follows the meter.
It houses the circuit
breakers for the
system and is used to
distribute the power to
individual circuits
throughout the
system.
Overcurrent
When a circuit uses too much electricity, an
overcurrent causes a circuit breaker to trip,
shutting down the power to that circuit.
The excessive heat caused by an overcurrent
condition may burn or damage a conductor’s
insulation and cause a fire.
A circuit breaker is a heat-sensitive switch, which
automatically trips when electricity demand is
too great which causes the temperature in the
conductor to get too hot.
Amps Volts Watts
The following relationship exists
between Amps, Volts and Watts.
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.
Identify and draw various symbols
used in drawing wiring diagrams or
schematics.
What symbols are used in drawing various
electrical devices?
In order to successfully draw a wiring circuit
on paper, one needs to use various symbols
that represent the equipment.
Cable Types
Cable Types
One is 14/2 with ground, which has one
black conductor, one white conductor, and
a bare ground conductor.
Cable Types (cont.)
A third type of cable is 14/3 with ground,
which has one black conductor, one white
conductor, one red conductor, and one
bare ground conductor.
Additional symbols are used
to identify terminals and
indicate if wires are spliced or
just crossing over.
Symbols (cont.)
Diagramming
Generally, black and red conductors
carry “hot” power or current from the
source to the devices within the
circuit.
The white conductor is always used to
carry the current back to the source.
Two and Three wire
How to wire a receptacle
All 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.
