REPUBLIC OF THE PHILIPPINES

SOUTH CENTRAL MINDANAO COLLEGE OF SCIENCE AND

TECHNOLOGY
Purok Rosal Barangay New Isabela
Tacurong City, Sultan Kudarat

COURSE NO. ET 113 Units: 3

Course Title: Philippine Electrical Code

VISION OF THE INSTITUTION

The academe envisions of providing graduates who are God fearing, patriotic, academically
competent and skillful individuals. It is committed to offer a safety environment with innovative
approaches in teaching and learning process and always be of service to its community.

MISSION OF THE INSTITUTION

The academe is fully committed to foster and sustain quality education, where students honed
their potential in a safe and caring environment.
Teachers passionately foster learning with competence and provide an avenue that may bring
out students skills in challenging and enjoyable way.
Administrators endeavor to be of help always to support and impose programs that will
promote quality teaching and learning.
Individuals in the locality are highly enjoined to share responsibility and be part of
implementing programs that will develop quality and skillful individuals.

CORE VALUES

DETERMINATION = determined to develop an institution that strive to achieve excellence

MOTIVATION = every individual in the academe is full of enthusiasm to pursue the objectives for the
betterment of the institution.
COOPERATION = working hand in hand and be sensitive with the needs of its stakeholders for the
betterment of the college.
CARING = emphatic to the welfare of every individual not only within the institution but with the
constituents in the locality.
LEARNING = we aspire of learning on the highest standard.
RESPECT = mutual respect should be afforded to every individual in the institution
COMMITMENT = we must be strongly committed to provide an academe that is conducive for
teaching and learning.

GRADING SYSTEM:
Module/Portfolio/activities 50%
Laboratory 30%
Exam 20%
100%

GRADE EQUIVALENT

PERCENTAGE NUMERICAL EQUIVALENT

GRADE DESCRIPTION
99-100 1.00 - Excellent
96-98 1.25
93-95 1.50
90-92 1.75
87-89 2.00 -Very Good
84-86 2.25
81-83 2.50
78-80 2.75
75-77 3.00
74 and Below FAILED
 Program/Course: ELECTRICAL INSTALLATION AND MAINTENANCE

Module Title: Philippine Electrical Code

INTRODUCTION:
Welcome to the Module “Philippine Electrical Code”. This module contains training materials
and activities for you to complete.
After completing this module ask your teacher to assess your competence. Result of your
assessment will be recorded in your competency profile. All the learning activities are designed for
you to complete at your own pace.

Inside this module you will find the activities for you to complete and relevant information sheets
for each learning outcome. Each learning outcome may have more than one learning activity.

This module is prepared to help you achieve the required competency, in receiving and relaying
information. This will be the source of information that will enable you to acquire the knowledge, skills
and attitude in Electrical Installation and Maintenance National Level independently at your own pace
or with minimum supervision or help from your teacher.

This module contains all the basic information and set of rules that will help guide you in
performing electrical installations that follows the standards set by the Philippine Electrical Code.

It covers the knowledge, skills and attitudes required electrical installation and maintenance

This module consists of ten (10) Learning Outcomes (LO’s) that contains learning activities for
knowledge supported with information sheets, job/operation sheets and self-check. Before attempting
to perform the manual exercises, see to it that you have already read and understood the
information/operation sheet and answered correctly the self-check provided in every Learning
Activities.

LEARNING OUTCOMES:

Upon completion of this module, the students shall be able to:

LO1. Know the brief history of Philippine Electrical Code

LO2. Know what is Philippine Electrical Code, its purpose and scopes
LO3. Understand basic Definitions and Terminologies
LO4. Identify Boxes and Enclosures
LO5. Identify Cables and Wires
LO6. Identify Raceways and Conduits
LO7. Identify Circuit breakers
LEARNING OUTCOME # 1:
BRIEF HISTORY OF PHILIPPINE ELECTRICAL CODE

Philippine Electrical Code RA 7920

The first documented case of a Code as a requirement of rules was published on 16th Nov.
1881 entitled “The Dangers of Electric Lighting”. The first NEC was developed in 1897, eighteen
years after the invention of incandescent light bulb by Thomas A. Edison. The 2009 PEC used the
2005 Edition of the National Electrical Code as referenced Code.

The Philippine Electrical Code Part 1 2009 Edition was based on NEC 2005.Regularly revised
(every three years) to reflect the evolution of products, materials, and installation techniques.  

LEARNING OUTCOME # 2:

WHAT IS PHILIPPINE ELECTRICAL CODE, ITS PURPOSE AND ITS SCOPES

What is “Philippine Electrical Code”?

The Philippine Electrical Code is used nationally as the basis for safeguarding persons,
buildings and its contents from hazards that may arise from the use of electricity.

These guidelines aim to attain efficient energy utilization in buildings. It contains energy
conservation guidelines for the design of buildings and their services. The guidelines are based on
present day viewpoint and are therefore subject to review, with regard to urgency and rigidity, as time
passes. The overall objective of the guidelines is to save energy in the building sector and pave the
way for designers/architects to apply energy conservation principles and techniques in their designs.
To be able to meet this objective, the guidelines were developed to address the aspects of design of
new buildings as well as the upgrading of existing buildings.
 There are two (2) categories of PEC rules:
1. Mandatory Rules- characterized by the use of the word “SHALL”.
2. Advisory Rules- characterized by the use of the word “SHOULD” or as stated as
recommendations of that which is advised but not required.

The use of PEC is mandated by the R.A. 7920 (formerly R.A.184), also known as the New
Electrical Engineering Law. Likewise, referral codes are also used which are mandated by their
corresponding laws.

1. P.D. 1096 – National Building Code

2. P.D. 1185 – Fire Code of the Philippines
3. Structural code
Purpose of Philippine Electrical Code (PEC). 

Strict compliance with provisions of this code will ensure safety in electrical installation and
construction, but not necessarily efficient, or adequate for good service or future expansion of
electrical use.
Scopes of Philippine Electrical Code

PEC covers the electric conductors including optical fiber cable and installed within or on, to or from:
1.Public and Private buildings
2. Electrical Generating plants
3. Temporary and permanent substations
4. Industrial plants
5. Transformer stations
6. Railway switchyards
7. Yards, carnival, parking, etc.
8. Watercraft
9. Dockyards
10. Airfields
11. Quarries and mines
12. Mobile homes, travel trailers and recreational vehicles
13. Offshore facilities
14. Other premises which requires electrical installation except to those which are done in; a) Aircraft
b) Motor Vehicles c) Railway rolling stocks

LEARNING OUTCOME # 3:

BASIC DEFINITIONS AND TERMINOLOGIES

Ampacity-the current, in amperes, that a conductor can carry continuously under the conditions of use
without exceeding its temperature rating
Appliance- utilization equipment, generally other than industrial that is normally built in standardized
sizes or types and is installed or connected as a unit to perform one or more functions such as clothes
washing, air conditioning, food mixing, deep frying, and so forth
Approved- acceptable to the authority having jurisdiction
Authority Having Jurisdiction (AHJ)- an organization, office, or individual responsible for enforcing
the requirements of a code or standard, or for approving equipment, materials, an installation, or a
procedure
Automatic- self-acting, operating by its own mechanism when actuated by some impersonal
influence, as, for example, a change in current, pressure, temperature, or mechanical configuration.  

Bonding (Bonded)- the permanent joining of metallic parts to form an electrically conductive path
that ensures electrical continuity and the capacity to conduct safely any current likely to be imposed.  

Branch Circuit- the circuit conductors between the final overcurrent device protecting the circuit and
the outlet(s). 

Cabinet- an enclosure that is designed for either surface mounting or flush mounting and is provided
with a frame, mat, or trim in which a swinging door or doors are or can be hung.  

Circuit Breaker- a device designed to open and close a circuit by nonautomatic means and to open
the circuit automatically on a predetermined overcurrent without damage to itself when properly
applied within its rating. 

Concealed- rendered inaccessible by the structure or finish of the building. Wires in concealed
raceways are considered concealed, even though they may become accessible by withdrawing them

Conductor, Bare- a conductor having no covering or electrical insulation whatsoever.  

Conductor, Insulated- a conductor encased within material of composition and thickness that is
recognized by this Code as electrical insulation.

Continuous Load- a load where the maximum current is expected to continue for 3 hours or more.  

Controller- a device or group of devices that serves to govern, in some predetermined manner, the
electric power delivered to the apparatus to which it is connected.

Cutout Box- an enclosure designed for surface mounting that has swinging doors or covers secured
directly to and telescoping with the walls of the box proper.  
Dead Front- without live parts exposed to a person on the operating side of the equipment.  

Demand Factor- the ratio of the maximum demand of a system, or part of a system, to the total
connected load of a system or the part of the system under consideration.  

Device- a unit of an electrical system that is intended to carry or control but not utilize electric
energy. 

Disconnecting Means- a device, or group of devices, or other means by which the conductors of a
circuit can be disconnected from their source of supply. 

Dust-tight- constructed so that dust will not enter the enclosing case under specified test conditions.  

Dwelling Unit- a single unit, providing living facilities for one or more persons, including permanent
provisions for living, sleeping, cooking, and sanitation. 

Dwelling, One-Family- a building that consists solely of one dwelling unit.

Dwelling, Two-Family- a building that consists solely of two dwelling units.

Dwelling, Multifamily- a building that contains three or more dwelling units.

Electric Sign- a fixed, stationary, or portable self-contained, electrically illuminated utilization

equipment with words or symbols designed to convey information or attract attention.  

Electrical Practitioner, Licensed- one who has undergone training in electrical engineering and has
complied with the requirements of Republic Act 7920 or otherwise known as the New Electrical
Engineering Law.  

Electrical Practitioner, Non-Licensed- an electrical practitioner that has not complied with the
requirements of RA 7920 or a qualified person with relevant education and experience to enable him
or her to perceive risks and to avoid hazards which electricity can create. 

Energized- electrically connected to a source of voltage. 

Equipment- a general term including material, fittings, devices, appliances, luminaires (fixtures),
apparatus, and the like used as a part of, or in connection with, an electrical installation.  

Explosion-proof Apparatus- apparatus enclosed in a case that is capable of withstanding an

explosion of a specified gas or vapor that may occur within it and of preventing the ignition of a
specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor
within, and that operates at such an external temperature that a surrounding flammable atmosphere
will not be ignited thereby.  

Feeder- all circuit conductors between the service equipment, the source of a separately derived
system, or other power supply source and the final branch-circuit overcurrent device.  

Fitting- an accessory such as a locknut, bushing, or other part of a wiring system that is intended
primarily to perform a mechanical rather than an electrical function.  

Fuse- an overcurrent protective device with a circuit-opening fusible part that is heated and severed
by the passage of overcurrent through it. 
Ground- a conducting connection, whether intentional or accidental, between an electrical circuit or
equipment and the earth or to some conducting body that serves in place of the earth.

Grounded- connected to earth or to some conducting body that serves in place of the earth.  

Grounded Conductor- a system or circuit conductor that is intentionally grounded.

Ground-Fault Circuit Interrupter (GFCI)- a device intended for the protection of personnel that
functions to de-energize a circuit or portion thereof within an established period of time when a
current to ground exceeds the values established for a Class A device.  

Ground-Fault Protection of Equipment- a system intended to provide protection of equipment from

damaging line-to-ground fault currents by operating to cause a disconnecting means to open all
ungrounded conductors of the faulted circuit. This protection is provided at current levels less than
those required to protect conductors from damage through the operation of a supply circuit
overcurrent device. 

Grounding Conductor- a conductor used to connect equipment or the grounded circuit of a wiring
system to a grounding electrode or electrodes.

Grounding Electrode- a device that establishes an electrical connection to the earth.  

Guarded- covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers,
casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach or contact by
persons or objects to a point of danger.  

Handhole Enclosure- an enclosure identified for use in underground systems, provided with an open
or closed bottom, and sized to allow personnel to reach into, but not enter, for the purpose of
installing, operating, or maintaining equipment or wiring or both.  

Hoist way- any shaft way, hatchway, well hole, or other vertical opening or space in which an
elevator or dumbwaiter is designed to operate. 

Inverse Time (as applied to circuit breakers)- a qualifying term indicating that there is purposely
introduced a delay in the tripping action of the circuit breaker, which delay decreases as the
magnitude of the current increases.  

Instantaneous Trip (as applied to circuit breakers)- a qualifying term indicating that no delay is
purposely introduced in the tripping action of the circuit breaker.  

Interrupting Rating- the highest current at rated voltage that a device is intended to interrupt under
standard test conditions. 

Isolated (as applied to location)- not readily accessible to persons unless special means for access
are used.

Labeled- equipment or materials to which has been attached a label, symbol, or other identifying
mark of an organization that is acceptable to the authority having jurisdiction and concerned with
product evaluation, that maintains periodic inspection of production of labeled equipment or materials,
and by who’s labeling the manufacturer indicates compliance with appropriate standards or
performance in a specified manner.  

Lighting Outlet- an outlet intended for the direct connection of a lamp holder, a luminaire (lighting
fixture), or a pendant cord lighting fixture), or a pendant cord terminating in a lamp holder.  

Listed- equipment, materials, or services included in a list published by an organization that is

acceptable to the authority having jurisdiction and concerned with evaluation of products or services,
that maintains periodic inspection of production of listed equipment or materials or periodic evaluation
of services, and whose listing states that the equipment, material, or services either meets
appropriate designated standards or has been tested and found suitable for a specified purpose.  
Live Parts- conductor or conductive part intended to be energized in normal use.  

Location, Damp- locations protected from weather and not subject to saturation with water or other
liquids but subject to moderate degrees of moisture. Examples of such locations include partially
protected locations under canopies, marquees, roofed open porches, and like locations, and interior
locations subject to moderate degrees of moisture, such as some basements, some barns, and some
cold storage warehouses.  

Location, Dry- a location not normally subject to dampness or wetness. A location classified as dry
may be temporarily subject to dampness or wetness, as in the case of a building under construction. 

Location, Wet- installations underground or in concrete slabs or masonry in direct contact with the
earth; in locations subject to saturation with water or other liquids, such as vehicle washing areas;
and in unprotected locations exposed to weather. Luminaire. A complete lighting unit consisting of a
lamp or lamps together with the parts designed to distribute the light, to position and protect the
lamps and ballast (where applicable), and to connect the lamps to the power supply. 

Motor Control Center- an assembly of one or more enclosed sections having a common power bus
and principally containing motor control units.  

Multi-outlet Assembly- a type of surface, flush, or freestanding raceway designed to hold

conductors and receptacles, assembled in the field or at the factory. 

Non-adjustable (as applied to circuit breakers)- a qualifying term indicating that the circuit breaker
does not have any adjustment to alter the value of current at which it will trip or the time required for
its operation.  

Non-automatic- action requiring personal intervention for its control. As applied to an electric
controller, non-automatic control does not necessarily imply a manual controller, but only that
personal intervention is necessary.  

Outlet- a point on the wiring system at which current is taken to supply utilization equipment. 

Overcurrent-   

Overload- operation of equipment in excess of normal, full-load rating, or of a conductor in excess of

rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous
overheating. A fault, such as a short circuit or ground fault, is not an overload.  

Panelboard- a single panel or group of panel units designed for assembly in the form of a single
panel, including buses and automatic overcurrent devices, and equipped with or without switches for
the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in
or against a wall, partition, or other support; and accessible only from the front.

Raceway- an enclosed channel of metal or nonmetallic materials designed expressly for holding
wires, cables, or busbars, with additional functions as permitted in this Code. Raceways include, but
are not limited to, rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquid tight
flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical
metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways,
surface raceways, wireways, and busways.  

Rainproof- constructed, protected, or treated so as to prevent rain from interfering with the
successful operation of the apparatus under specified test conditions.  

Raintight- constructed or protected so that exposure to a beating rain will not result in the entrance
of water under specified test conditions. 

Receptacle- a receptacle is a contact device installed at the outlet for the connection of an
attachment plug. A single receptacle is a single contact device with no other contact device on the
same yoke. A multiple receptacle is two or more contact devices on the same yoke. 

Receptacle Outlet- an outlet where one or more receptacles are installed.

Remote-Control Circuit- any electric circuit that controls any other circuit through a relay or an
equivalent device. 

Service- the conductors and equipment for delivering electric energy from the serving utility to the
wiring system of the premises served.  

Service Cable- service conductors made up in the form of a cable.  

Service Conductors- the conductors from the service point to the service disconnecting means.  

Service Drop- the overhead service conductors from the last pole or other aerial support to and
including the splices, if any, connecting to the service-entrance conductors at the building or other
structure. 

Service-Entrance Conductors, Overhead System- the service conductors between the terminals of
the service equipment and a point usually outside the building, clear of building walls, where joined by
tap or splice to the service drop.  

Service-Entrance Conductors, Underground System- the service conductors between the

terminals of the service equipment and the point of connection to the service lateral.  

Service Equipment- the necessary equipment, usually consisting of a circuit breaker(s) or switch(es)
and fuse(s) and their accessories, connected to the load end of service conductors to a building or
other structure, or an otherwise designated area, and intended to constitute the main control and
cutoff of the supply.  

Service Point- the point of connection between the facilities of the serving utility and the premises
wiring.  
Setting (of circuit breakers)- the value of current, time, or both, at which an adjustable circuit
breaker is set to trip.   

Show Window- any window used or designed to be used for the display of goods or advertising
material, whether it is fully or partly enclosed or entirely open at the rear and whether or not it has a
platform raised higher than the street floor level.  

Signaling Circuit- any electric circuit that energizes signaling equipment.  

Solar Photovoltaic System- the total components and subsystems that, in combination, convert
solar energy into electrical energy suitable for connection to a utilization load.

Switchboard- a large single panel, frame, or assembly of panels on which are mounted on the face,
back, or both, switches, overcurrent and other protective devices, buses, and usually instruments.
Switchboards are generally accessible from the rear as well as from the front and are not intended to
be installed in cabinets. 

Thermally Protected (as applied to motors)- the words Thermally Protected appearing on the
nameplate of a motor or motor compressor indicate that the motor is provided with a thermal
protector. 

Thermal Protector (as applied to motors)- a protective device for assembly as an integral part of a
motor or motor-compressor that, when properly applied, protects the motor against dangerous
overheating due to overload and failure to start.
Utilization Equipment- equipment that utilizes electric energy for electronic, electromechanical,
chemical, heating, lighting, or similar purpose

Voltage (of a circuit)- the greatest root-mean-square (rms) (effective) difference of potential between
any two conductors of the circuit concerned. 

Voltage, Nominal- a nominal value assigned to a circuit or system for the purpose of conveniently
designating its voltage class (e.g.,120/240 volts, 480Y/277 volts, 600 volts). The actual voltage at
 which a circuit operates can vary from the nominal within a range that permits satisfactory operation
of equipment.  

Watertight- constructed so that moisture will not enter the enclosure under specified test conditions.  

Weatherproof- constructed or protected so that exposure to the weather will not interfere with
successful operation.

LEARNING OUTCOME # 4:

BOXES AND ENCLOSURES

An electrical enclosure is a cabinet for electrical or electronic equipment to

mount switches, knobs and displays and to prevent electrical shock to equipment users and protect
the contents from the environment. The enclosure is the only part of the equipment which is seen by
users. It may be designed not only for its utilitarian requirements, but also to be pleasing to the eye.
Regulations may dictate the features and performance of enclosures for electrical equipment in
hazardous areas, such as petrochemical plants or coal mines.
 National Electrical Manufacturers Association (NEMA) publishes NEMA enclosure
type standards for the performance of various classes of electrical enclosures. The NEMA standards
cover corrosion resistance, ability to protect from rain and submersion, etc.
Electrical enclosures are usually made from rigid plastics, or metals such as steel, stainless
steel, or aluminum. Steel cabinets may be painted or galvanized. Mass-produced equipment will
generally have a customized enclosure, but standardized enclosures are made for custom-built or
small production runs of equipment. For plastic enclosures ABS is used for indoor applications not in
harsh environments. Polycarbonate, glass-reinforced, and fiberglass boxes are used where stronger
cabinets are required, and may additionally have a gasket to exclude dust and moisture.
Metal cabinets may meet the conductivity requirements for electrical safety bonding and shielding of
enclosed equipment from electromagnetic interference. Non-metallic enclosures may require
additional installation steps to ensure metallic conduit systems are properly bonded.

4 COMMON NEMA-TYPE ELECTRICAL ENCLOSURES

1. NEMA 1: These boxes offer the least amount of protection and are generally used inside. They offer
a limited amount of protection against light dust, dirt, and accidental contact with electrical equipment.
2. NEMA 3: These can be used indoors and outdoors. You will find them outside more often as they
give additional protection against falling dirt, rain, snow, sleet, and external ice formation.

3. NEMA 4: For greater protection

against harsh weather conditions, a NEMA 4 may be what you are looking for. They have a watertight
feature and are often used to protect outdoor wiring systems and mounted telecommunications
4. NEMA 4X: This type has the same protection as a NEMA 4 but with added protection against
corrosion. Where there is an excess amount of moisture, these boxes can help prevent condensation
build-up and protect sensitive electrical components.

COMMONLY USED BOXES

1. UTILITY BOX
An electrical utility box is typically a rectangular, open-faced box mounted in a wall. It serves
to house an electrical device, such as an electrical receptacle or switch or a GFI (ground fault
interrupter).
2. JUNCTION BOX
Junction boxes are an essential part of the electrical wiring systems for homes and buildings
alike. The purpose of these boxes, which are often made from metal or plastic, is to house and
safely protect a structure's electrical connections. Whenever you splice wires together while
installing residential circuitry, the electrical code requires you to enclose the connections in
a junction box. This safety measure prevents fires that can occur when the wires overheat and
also protects people from getting shocked by live wires.

3. SQUARE BOX
Square boxes come in standard depths of 1 1/4 to 2 1/8 inches, but their square corners give
them additional interior space, providing maximum volume for multiple conductors and
connectors. For this reason, 4-inch square boxes often are used to run multiple conductors in
two or more directions. They are also commonly used as junction boxes and can also be
installed in ceilings or walls for supporting lighting fixtures or for housing switches or receptacles
when matched with the
proper cover plates.
4. PULL BOX
In electric wiring, a box (with a removable cover) that is inserted in one or more runs of
raceway to facilitate the pulling of conductors through the raceway. junction box: An electrical
junction box is an enclosure housing electrical connection, to protect the connections and
provide a safety barrier.
5. Round Pan Electrical Boxes

Round pan, or "pancake," boxes typically are only 1/2 inch or 3/4 inch deep. They are used
most commonly for ceiling- or wall-mounted light fixtures that weigh no more than 50 pounds.
Some types of specially rated metal pan boxes may be used for mounting ceiling fans, but not
all pan boxes may be used for this purpose. It’s important that the fixture wires can be properly
connected and fitted within the round pan box. These are shallow electrical boxes with only
enough space for fitting two or three electrical connections. If there are more wire connections
to be made, you will probably need a full-sized octagon or round electrical box with more
volume. The number of wires in the box should never exceed its safe fill capacity. 

6. Ceiling Fan-Rated Electrical Box

Ceiling fan boxes come in several different types and sizes, including 1/2-inch-deep "pancake"
versions and standard 2 1/8-inch-deep boxes. They are usually round but may be octagonal.
Do not use standard round or octagonal boxes for installing ceiling fans. Ceiling fan boxes
require special fastening to withstand the dynamic loading of a rotating fan.
7. Outdoor Electrical Box

Weatherproof outdoor boxes are sealed enclosures designed for mounting to the surface of
exterior walls, roof overhangs, decks, and other structures. They are used for installing outdoor
receptacles (outlets) and light fixtures. Outdoor boxes must have an outdoor cover or fixture
rated for damp or wet locations, depending on the application. Plastic outdoor boxes are
usually made from high-impact PVC, while metal outdoor boxes are typically made from
aluminum rather than steel. 

8. Box Extenders
Box extenders, or extension rings, come in a variety of sizes and shapes to match standard
electrical boxes. They are shaped like boxes but have no back. They are designed to be
installed onto the front of standard electrical boxes to increase the box capacity or to bring the
box flush with the drywall or other surface material.
LEARNING OUTCOME # 5:

CABLES AND WIRES

Basic differences between Wires and Cables

The basic key difference between wires and cables is that a wire is a single conductor whereas
a cable is a group of conductors. Although, these conductors are made of a common material- copper
or aluminum. Usually, the wires are bare and are twisted. But, some of the wires are coated with thin
PVC layer. And in case of cables, they run parallelly and are twisted or bonded together to form a
single case. For the safety purpose, an inner and outer sheath is made.

Wire vs. Cable

Whether it's a single strand or multiple strands grouped together, if there is only one conductor
it is a wire. Likewise, if there are multiple conductors, but they have no insulation around them, they
would be classified as a single conductor, making it a wire.

Wire

A wire is measured by diameter. According to the diameter of the wire, it will be measured by a
gauge number. The smaller the gauge number, the thicker the wire. The perfect gauge that is used in
residential applications is 10 & 20. But, do keep in mind that big wires carry more current and can
damage household appliances by burning the fuse.

Cable

A cable contains a hot wire carrying the current, a neutral wire to complete the loop and a
grounding wire as well. A cable is classified by the total number of wires it is made up of and their
gauge.

Different uses of Wire and Cable

Use of Wire

A wire is used to carry electricity, to bear the mechanical loads, to transmit telecommunication
signals, for heating jewelry, clothing, automotive or any industrial manufactured parts like pins, bulbs
and needles.

Use of Cable

A cable is used for power transmission, for telecommunication signals or to carry electricity.
Types of Wire and Cable

Types of Electrical Wires

1. Solid – A solid wire has a single conductor and is either insulated or bare and it is usually
protected by a colored sheath. This wire offers a lower resistance and is best to use in higher
frequencies.

2. Stranded – A stranded wire contains many thin wire strands that are twisted together. These
wires are used where the flexibility is required, stranded wire can be used over a long period of
time. Comparatively, the stranded wire has larger cross-sectional area than the solid wire.

Types of Electrical Cables

1. Twisted pair cable – A twisted pair cable includes 2 cables that are twisted together. This
twisting can avoid the noise produced by magnetic coupling and thus it is used to carry signals.
Twisted pair cable is generally used in data communication and telecommunication.
 2. Multi-conductor cable – This cable has 2 or more than 2 conductors which are insulated and
their purpose is to protect the signal integrity. Both twisted pair cables and multi-conductor are
known as balanced line configuration cables.

3. Coaxial cable – A coaxial cable has an inner conductor which is surrounded by a parallel
outer foil conductor which is protected by insulating layers. In the cable, the 2 conductors are
being separated from each other by an insulating dielectric. These cables are generally used in
TV cable as its performance is more stable than the twisted pair cable.

4. Fiber optic cable – The fiber optic cable transmits the signals through a bunch of glass threads
and comparatively, it has a greater bandwidth than metal conductors and that means they can carry
more information and data. For this reason, fiber optic cables are used instead of traditional copper
cables.
Wire Types & It’s Insulations & Characteristics

Wire Ampacity
Wire ampacity is the maximum electrical current (Amperes or “Amps”) that safely exist in
a given size of conductor. Wires are made of 2 basic components: a copper conductor and the wire
insulation that surrounds it. The temperature of the conductor will rise as the current level increases.
Wire Ampacity Table

LEARNING OUTCOME # 6:
RACEWAYS AND CONDUITS
Raceways are defined as enclosed channels of metal or nonmetallic material designed expressly
for holding wires or cables. Branch-circuit installation using a raceway (conduit) wiring method is
seldom used in residential wiring.  However, some areas of the country require that all wiring in a
house be installed in a raceway wiring method. Raceways should be installed as a complete system
and be securely fastened in place and supported by an approved retainer.

1. Rigid Metal Conduit (RMC)

Rigid metal conduit, or RMC, is heavy-duty galvanized steel tubing that is installed with threaded
fittings. It is typically used outdoors to provide protection from damage and can also provide
structural support for electrical cables, panels, and other equipment. RMC is sold in 10- and 20-
foot lengths and has threads on both ends.

2. Intermediate Metallic Conduit (IMC)

Intermediate metal conduit, or IMC, is a thinner, lighter-weight version of rigid metal conduit and is
approved for use in all of the same applications as RMC. Because IMC is lighter and easier to
work with than RMC, it is more common in new construction.

3. Electrical Metallic Tubing (EMT)

Another example of a rigid electrical conduit is EMT (electrical metal tubing), which is most
commonly made of galvanized steel but can also be aluminum. EMT is also called "thin-wall"
conduit because it is thin and lightweight, especially compared to RMC. EMT is rigid but can be
bent with a simple tool called a conduit bender.

EMT is installed with couplings and fittings that are secured with setscrew or compression-type
fasteners. The tubing itself is not threaded like RMC and IMC. Common sizes of EMT include 1/2-
inch, 3/4-inch, and 1-inch. It is commonly used for exposed indoor wiring runs in residential and
light commercial construction. If installed outdoors in exposed locations, it must be assembled
with special watertight fittings.

4. Electrical Non-Metallic Tubing (ENT)

Electrical nonmetallic tubing (ENT) is flexible corrugated plastic tubing that is moisture-resistant
and flame-retardant. It is easy to bend and installs with snap-lock or glued plastic fittings. Unlike
EMT, non-metallic tubing cannot be installed in exposed locations, so it is commonly used inside
walls. In addition to installation in standard wood- or metal-frame walls, ENT can be installed
inside concrete block structures and can be covered with concrete. Due to the blue color of one
common brand of this conduit, ENT is nicknamed "smurf tube," after the Smurfs cartoon
characters.

5. Flexible Metal Conduit (FMC)

Flexible metal conduit (FMC) is also called "Greenfield," after the name of its inventor. It has a
spiral construction that makes it flexible so it can snake through walls and other structures.
Standard FMC is used in dry indoor locations, often for short runs between a wall box and a motor
or fixed appliance, such as a garbage disposer.

6. Liquid-tight Flexible Metal Conduit (LFMC)

Liquid-tight flexible metal conduit (LFMC) is a special type of flexible metal conduit that has a
plastic coating and is used with sealed fittings to make it watertight. It is commonly used with
outdoor equipment, such as air conditioner units.

7. Rigid PVC Conduit

Rigid polyvinyl chloride (PVC) is similar to plastic plumbing pipe and is installed with plastic fittings
that are glued in place. It can be bent after being heated in a portable heater box. Because the
conduit tubing and fittings are glued together, the conduit assemblies can be watertight, making
PVC suitable for direct burial in the ground for many applications. It is also allowed in corrosive
environments.

8. Galvanized Rigid Conduit (GRC)

GRCs are created by taking one of your above RMC, RSD, or IMC and galvanizing it via hot
dipping it in zinc. The zinc coating provides extra coating in areas that are wet or highly
corrosive. GRCs are interchangeable with most RMC, RSD, and IMC to use when only an area
of your piping needs additional protection. PVC coating can be added on top of GRC coating
for ECs that will be exposed to chemicals and other highly abrasive materials.

9. Corrugated Plastic Conduit (CPC)

Plastic corrugated conduit is widely used in wire and cable protection. Plastic corrugated

conduit is used to protect wire and cables, especially in some terrible situation. The other conduit
 could not be fixed easy, and also have a good protection of them. Compare to other conduit and
chain, plastic corrugated conduit has the least weight, easy to take and be fixed, also with
competitive price.

10. Cable Trays

It heads off the possibility of a disorganized mass of conductors that are difficult to trace when
changes must be made or faults located
The NEC says a cable tray system is a unit or assembly of units or sections and associated
fittings forming a structural system used to securely fasten or support cables and raceways

10. PVC Plastic Mouldings

PVC plastic mouldings are used to secure and protect exposed wires and cables installed in a
surface type installation. Plastic mouldings also known as “Cable/Wire Trunking”. Trunking is
installed onto a wall or surface as opposed to within it and is also a great way of hiding
unsightly wiring from view. It's typically offered in a variety of materials although plastic trunking is
the most common and there are also various widths and sizes available to suit many locations
and requirements. Electrical trunking is often manufactured with a slide and hinge system which
allows easy access to the ducting once installed for ease of maintenance.

11. Wireways
Wireways are troughs with hinged or removable covers for housing and protecting electric
wires and cable. Conductors are laid into the wireway after the wireway has been installed
as a complete system. Wireways are designed to protect cables from environmental
contaminants such as dust, dirt, oil, and moisture. Wireways—sometimes known as "troughs"
 or "gutters" within the electrical contracting field—are commonly used to control wiring in
environments where contaminants may cause problems.

LEARNING OUTCOME # 7:

CIRCUIT BREAKERS

A circuit breaker is an automatically-operated electrical switch designed to protect an electrical

circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition
and, by interrupting continuity, to immediately discontinue electrical flow. Unlike a fuse, which
operates once and then has to be replaced, a circuit breaker can be reset (either manually or
automatically) to resume normal operation. Circuit breakers are made in varying sizes, from small
devices that protect an individual household appliance up to large switchgear designed to protect high
voltage circuits feeding an entire city.

Low voltage circuit breakers

Low voltage (less than 1000 VAC) types are common in domestic, commercial and industrial
application, include:
 MCB (Miniature Circuit Breaker)—rated current not more than 100 A. Trip characteristics normally
not adjustable. Thermal or thermal-magnetic operation. Breakers illustrated above are in this
category.

 MCCB (Molded Case Circuit Breaker)—rated current up

to 2500 A. Thermal or thermal-magnetic operation. Trip
current may be adjustable in larger ratings.
Magnetic circuit breaker
Magnetic circuit breakers use a solenoid (electromagnet) whose pulling force increases with the
current. Certain designs utilize electromagnetic forces in addition to those of the solenoid. The circuit
breaker contacts are held closed by a latch. As the current in the solenoid increases beyond the
rating of the circuit breaker, the solenoid’s pull releases the latch which then allows the contacts to
open by spring action. Some types of magnetic breakers incorporate a hydraulic time delay feature
using a viscous fluid. The core is restrained by a spring until the current exceeds the breaker rating.

Thermal magnetic circuit breaker

Thermal magnetic circuit breakers, which are the type found in most distribution boards, incorporate
both techniques with the electromagnet responding instantaneously to large surges in current (short
circuits) and the bimetallic strip responding to less extreme but longer-term over-current conditions.
Electrical current exceeding the breaker-overload rating heats the bimetal enough to bend it toward
the trip bar. As the bimetal bends, it touches and rotates the trip bar to open the circuit.
Common trip breakers
When supplying a branch circuit with more than one live conductor, each live conductor must be
protected by a breaker pole. To ensure that all live conductors are interrupted when any pole trips, a
“common trip” breaker must be used. These may either contain two or three tripping mechanisms
within one case, or for small breakers, may externally tie the poles together via their operating
handles. Two pole common trip breakers are common on 120/240-volt systems where 240-volt loads
(including major appliances or further distribution boards) span the two live wires. Three-pole
common trip breakers are typically used to supply three-phase electric power to large motors or
further distribution boards.