ELECTRICAL SYSTEMS
• GENERATOR – M.E to E.E.
• MOTOR – E.E. to M.E.
Electricity
phenomenon; manifestation
• BATTERY – electrochemical; electrolysis Primary –
nonrenewable
Principally made up of atoms (electron, proton, neutron)
Secondary – rechargeable
• 2 General Classes: Dynamic and Static
SYSTEM COMPONENTS OF BUILDING
ELECTRIC CURRENT - flow in an electric circuit (amperes)
• 3 CATEGORIES
Classifications: Direct Current (DC)/Alternating Current (AC
1.
Amperes: Unit
Amperage: Current
2.
Ampacity: Current-carrying capacity (w/o undue heating
ELECTRIC CIRCUIT – path for electric current w/ EMF
applied
Electromotive Force (EMF) - force which causes movement
of electricity in a conductor
• Circuit Diagram – electrical layout
• Close Circuit – complete; continuous path
Open Circuit – broken, incomplete, disconnected
Two Types: Parallel/Series
Short Circuit: bridging
• Shunt: circuit branching
ELECTRIC CURRENT CLASSIFICATION
1.
2.
DIRECT CURRENT
• Flows in one direction (- to +)
• Battery/dry cell
• 2 types of DC: continuous/pulsating
(fluctuating)
ALTERNATING CURRENT
• Reverses in direction
• Frequency: 60 cps (60 Hertz)
• Phase: SP/3P
• 240VAC, 60Hz, SP
3.
Wirings and Raceways
Conductors – offers low resistance Insulators –
prevents flow of electric current
Raceways - channel
Power Handling Equipment
transformer, switchboard/switchgear, panelboard,
service switch, circuit breakers/fuse
Utilization Equipment – actual use
Fixtures
Switches
Convenience Outlets
WIRES AND CABLES
1. FMC/MC/AC – BX; flexible
2. NMC/NM – ROMEX; sheat
3. GENERAL WIRING: THERMOPLASTIC (PEC)
4. MI – jacketed
5. SNM – telecommunication/submarine cable
6. SE/USE – aerial/underground
7. UF – direct burial to ground
8. TC – open wireway/support/tray
9. FC – system furniture application/cable
management
10. FCC – general purpose
BUSBAR: Busway, Busduct
CABLEBUS; rounded
RACEWAYS
1.
2.
Floor Raceway
• underfloor raceway – conventional
installation
• cellular metal floor raceway – rib
decking/raised floor system
• cellular concrete floor raceways – T-joist/
precast concrete slab with built in pipes
Ceiling Raceway
• Power and Control Tray Cable (TC)
• Busbar
• Cablebus
POWER HANDLING EQUIPMENTS
1.
TRANSFORMER – voltage to voltage
• Outdoor Transformers
H-frame – 1000 kva
OHM’s LAW – relationship of EMF, Current, Resistance
Cluster mounted – 225 kva
Formula: I = V/R V=IR R=V/I
Pad mounted – 120V to 240V
Other Electrical Terminologies
• Indoor Transformers
Dry Type – pad mounted; switchboard
Askarel – synthetic non-flammable liquid
• DEVICE – does not consume electricity
• WATT – rate of power; power consumption; heat volts +
ampere
Oil-insulated – for transformer vault
Watt Meter – any one time
• Transformer Rating: stepped up/stepped down
Watt-Hour Meter – periodic; KWH
Meter/Electricity Meter
POWER HANDLING EQUIPMENTS
• ALTERNATOR – AC generator
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1.
SWITCHBOARD/SWITCHGEAR – free standing
assemblies of switches, fuses/circuit breakers
2.
3.
4.
• Unit Substations (Transformer Load
Center) – large facility
PANELBOARD – final distribution point; PP/LP
2. Instant Start (Slimline) – w/o a starter
3. Rapid Start – bi-pins
• Main Panelboard
CONDUITS
• Distribution Panelboard
pipes, tubings (electrical raceway) Materials (Metallic or
Nonmetallic) Make
SERVICE SWITCH – large switch
• disconnecting apparatus
• service disconnecting means
• applied on apartments: meter banks
CIRCUIT PROTECTIVE DEVICES – overload/short
circuit
• FUSE – alloy link or wire; fusible link;
nonrenewable
Plug Fuse – dwelling (5-30 amps)
Cartridge Fuse – (5-60 amps)
Knife Blade Fuse – (61-600 amps); DE/SE
• CIRCUIT BREAKERS – electromechanical device
Thermal Pigtail (Copper) – senses heat Magnetic
Pigtail (Copper) – senses load
1. Rigid Metal (RSC, EMT)
2. Flexible Metal (BX)
3. Rigid Nonmetal (Plastic, etc.)
4. Flexible Nonmetal (Plastic, etc.)
CONDULETS/UNILETS (Conduit Fittings)
1. Straight and angle couplings
2. Elbow Fittings
3. Tee and Cross connections Condulets
• F – standard outlet box fittings
UTILIZATON EQUIPMENT
FIXTURES/LUMINAIRES
1. Incandescent Lamp/Bulb – filament
2. Fluorescent Lamp/Tube – cathode
CONDUITS/FITTINGS/CONDULETS
BRANCH CIRCUITS
ELECTRICAL BOXES
• SE – Service Entrance
• L – Elbow or Turn Fittings
• C – Through Fittings
• T – Through Fittings w/ 90° take off
• E – end of run to types of motors, transformers,
equipments
• LL/LR - 90° turns where mounting is not suitable for LB
PLATES
• LB – when run of conduit comes must run thru
wall/ceiling ELECTRICAL BOXES • Outlet Box – cable ends
Lighting Outlets
• Utility Box – outlets, switches
Receptacle/Convenience Outlets
• Pull Box – facilitates pulling
FIXTURES/LUMINAIRES INCANDESCENT BULB
• Junction Box – joining, splicing
1. Filament
• Cut-out Box – metal box
2. Gas
OUTLETS
3. Lead-in-wires
Lighting Outlet – Single Gang, Two Gang, Three gang
(PLATE)
4. Stem Press
5. Exhaust Tube
6. Base
Convenience Outlet – Receptacle Outlet
Duplex Convenience Outlet/Single Convenience Outlet
FM – Flash mounted SM – Surface mounted
7. Fuse
8. Mica Disc
9. Button Rod
10. Button
11. Support Wires
12. Soft Glass Hard Glass Inside frosted – white silica
Electrical Wires & Cables
•Wire -a single electrical
conductor
•Cable -a group of
wires swathed in
sheathing
FIXTURES/LUMINAIRES FLUORESCENT LAMP
1. Cylindrical Glass Tube – phosphor
2. Cathode – argon and low pressure mercury vapor
3. Ballast – limits current
4. Starter - switch
TYPES:
1. Pre-Heat Starting - CFL
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Various Features Of Electrical Wire
1 . Size of Wires
• Each application requires a certain wire size for
installation, and the right size for a specific application is
determined by the wire gauge. Sizing of wire is done by
the American Wire Gauge system. Common wire sizes are
10, 12 and 14 – a higher number means a smaller wire
size, and affects the amount of power it can carry
• For example
• low-voltage lamp cord - 10 Amps - 18-gauge
wire
• service panels or subpanels - 100 Amps - 2gauge wire
2.
Wire Lettering
• The letters THHN, THWN, THW and XHHN
represent the main insulation types of individual
wires. These letters depict the following NEC
requirements:
T – Thermoplastic insulation
H – Heat resistance
HH – High heat resistance (up to 194°F)
W – Suitable for wet locations
N – Nylon coating, resistant to damage by oil or
gas
X – Synthetic polymer that is flame-resistant
Insulation
Typical materials used for insulation:
• Thermoplastic high heat-resistant nylon
(THHN)
• Thermoplastic high heat-resistant nylon waterresistant (THWN)
• Cross-linked polyolefin (XLPO)
• Ethylene propylene rubber (EPR)
• Flame retardant ethylene propylene (rubber)
(FREP/FR-EPR)
• Cross-linked polyethylene (XLPE/XHHW)
Jacket
•Typical jacket materials:
•Polyvinyl chloride (PVC)
•Chlorinated polyethylene (CPE)
•Low smoke zero halogen (LSZH)
• Main Feeder Wires
- Main power feeder wires are
the wires that connect the service
weather head to the house. They’re
made with stranded or solid THHN wire
and the cable installed is 25% more
than the load required.
• Panel Feed Wires - Panel feed cables
are generally black insulated THHN wire. These
are used to power the main junction box and
the circuit breaker panels. Just like main power
feeder wires, the cables should be rated for
25% more than the actual load.
• Non-Metallic Sheathed Wires - Nonmetallic sheath wire, or Romex, is used in most
homes and has 2-3 conductors, each with
plastic insulation, and a bare ground wire. The
individual wires are covered with another layer
of non-metallic sheathing. Since it’s relatively
cheaper and available in ratings for 15, 20 and
20 amps, this type is preferred for in-house
wiring
3. Types of Wires
There are mainly 5 types of wire:
• Triplex Wires - Usually used in singlephase service drop conductors,
between the power pole and weather
heads. They are composed of two
insulated aluminum wires wrapped with
a third bare wire which is used as a
common neutral. The neutral is usually
of a smaller gauge and grounded at
both the electric meter and the
transformer.
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• Single Strand Wires - Single strand
wire also uses THHN wire, though there are
other variants. Each wire is separate and
multiple wires can be drawn together through a
pipe easily. Single strand wires are the most
popular choice for layouts that use pipes to
contain wires
4. Color Codes
Different color wires serve
different purposes, like:.
• Black : Hot wire, for switches or
outlets.
• Red : Hot wire, for switch legs. Also
for connecting wire between 2
hardwired smoke detectors.
• Blue and Yellow : Hot wires, pulled in
conduit. Blue for 3-4 way switch
application, and yellow for switch legs
to control fan, lights etc.
• White : Always neutral.
• Green and Bare Copper : Only for
grounding
5. Wire Gauge, Ampacity and Wattage
Load
• To determine the correct wire, it is
important to understand what ampacity
and wattage a wire can carry per gauge.
•Wire gauge - the size of the wire
•Ampacity - how much electricity can
flow through the wire
•Wattage -the load a wire can take,
which is always mentioned on the
appliances.
ELECTRICAL SWITCH
 electromechanical devices that are
used in electrical circuits to control
power
detect when systems are outside their
operating ranges
 signal controllers of the whereabouts
of machine members and work pieces
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provide a means for manual control of
machine and process functions
 control lighting, and so on.
Switch function is defined by the
number of poles and throws the switch
has. “Poles” are individual circuits the
switch controls (e.g., a “3-pole” switch
has three circuits controlled by the
same throw). “Throws” are unique
positions or settings for the switch (e.g.,
a “double-throw switch” can operate in
two different positions like on/off,
high/low, etc.). Combining the number
of poles and throws gives a succinct
description of the switch’s function, so
the function of, for instance, a “singlepole, double-throw” switch is implicit.
Switch types are commonly abbreviated
for brevity, so a single-pole, doublethrow switch would be referred to as an
“SPDT” switch. The simplest type of
switch is a single-pole, single-throw
(SPST) device that functions as an on-off
switch. Double-pole, double-throw
(DPDT) switches are commonly
employed as internal polarity reversing
circuits. Switches of up to four poles
and three throws are common and
some have breaks
TYPES OF ELECTRICAL SWITCHES
FOOT SWITCHES
electro-mechanical devices used to
control power in an electrical circuit by
foot pressure. They are often used on
machines where an operator needs his
or her hands to stabilize a workpiece.
They are also commonly used in
hospital equipment and office
machines.
PRESSURE SWITCHES
LEVEL SWITCHES
 Level switches are used extensively in
the process industries to monitor tank
and hopper levels. They are used in
everyday applications as well.
 used to detect the level of liquids,
powders, or solids. They are
mounted in tanks, hoppers, or bins,
and can provide output to a control
system.
Pressure switches are used to keep
pressure within limits in lubrication
systems where over-pressure or underpressure conditions can result in
damage to the machine.
-electro-mechanical devices used to
sense fluid pressure and provide output
signals to a controller. They often
employ a diaphragm as the sensing
means.
PULL CHAIN SWITCHES
LIMIT SWITCHES
Limit switches are used in many
common consumer machines such as
washing machines. In their ruggedized
form they are used in many types of
manufacturing facilities such as steel
mills and paper plants.
- designed to sense motion and position
mechanically and provide output signals
to a controller. They are available as
bare switches, or in rugged enclosures
intended for the tough environment of
a factory floor
 Pull chain switches can be used for
manual control of overhead lights and
fans. As rope-pull switches, they are
used for emergency stop devices, for
example along the length of an inrunning roll. They are sometimes called
Rope Pulls or Cable Pulls.
 electro-mechanical devices that are
hand operated and used to switch a
circuit on and off, or step a circuit
through increasing power levels. Their
most common application is in lighting
where they are used to switch lamps.
Pull Rope Switches are used as
emergency stop devices.
PUSH BUTTON SWITCHES
MEMBRANE SWITCHES
Membrane Switches are common in
commercial products where
incorporating all control functions into a
single device can save costs over using
discrete switches.
-  circuit board based electromechanical devices that provide tactile
control of processes and machines
without the need for individual push
switches. They are often custom
designed to suit a particular process.
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also referred to as Push Switches, are
hand operated electro-mechanical devices used
for switching circuits. They are the most
common variety of switch used on industrial
control panel.
 Key specifications include singlethrow or double-throw switching function,
contact type, mounting type, actuator type, and
panel cut-out diameter. The 30 mm cut-out is a
common industrial size.
 Pushbutton switches make up the
bulk of manual switches used in industrial
controls. They are available in a variety of
shapes and styles to cover almost any manual
control scenarios.
ROCKER SWITCHES
Slide switches are used in electrical and
electronic equipment where the switching
range can be limited and economy is important.
They are commonly used for on-off buttons or
just as a general control switch.
Slide switches are used in electrical and
electronic equipment where the switching
range can be limited and economy is important.
They are commonly used for on-off buttons or
just as a general control switch.
THUMBWHEEL SWITCHES
hand operated electro-mechanical devices used
for switching circuits. The switch operator
position, raised or depressed, gives a quick
visual indication of the circuit's on or off status.
 Key specifications include single-throw or
double-throw switching function, mounting
type, actuator type, and panel cut-out
dimensions.
 Rocker switches are used for manual
switching in many industrial controls as well as
for control of consumer goods and office
machines
ROTARY SWITCHES
also referred to as Pushwheel Switches, are
hand operated electromechanical devices used
to control electrical circuits with a rotatable
wheel. They display a numeric value
corresponding to the switch position.
 Key specifications include number of
positions, mounting type, actuator type, coded
output type, and panel cut-out dimensions.
 Thumbwheel switches are widely used in the
aviation industry for flight controls,
instrumentation, and controllers. They are also
used in test and measurement equipment and
computer devices
TOGGLE SWITCHES
 Rotary switches are used to provide a visually
verifiable means of switch position, allowing
operators to tell with a glance whether a circuit
is energized or not. They are also called Paddle
Switches
 hand operated electro-mechanical devices
used for switching circuits and selecting
functions. Rotary switches can be two-position,
on-off, or they can have multiple discrete stops.
 Key specifications include number of poles,
number of positions, construction type,
mounting type, and panel cut-out diameter for
panel mount switches.
SLIDE SWITCHES
 hand operated electro-mechanical devices
used for switching circuits. They are actuated by
a lever which is pushed through a small arc.
Moving the lever back and forth opens and
closes an electrical circuit, while the lever
position gives a quick visualization of the circuit
status.
 Key specifications include single-throw or
double-throw switching function, 1- axis, 2-axis,
or 3-axis configuration, or in some cases
omnidirectional or joystick toggle configuration,
and actuator type.
 Toggle switched are used extensively in
electronics panels and instrumentation where a
wider range of switching function is required,
such as in switchboards.
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WALL SWITCHES
Types of Electrical Outlets
ELECTRICAL OUTLETS (also known as outlets,
electrical sockets, plugs, and wall plugs) allow
electrical equipment to connect to the electrical
grid.
 hand operated electro-mechanical devices
used in residential and commercial buildings
most commonly for lighting control. They are
also used to control ceiling fans and electrical
outlets.
 Key specifications include combination
device function, actuator type, and additional
switch functions such as dimmer control, fan
speed control, or timer-based switching.
The electrical grid provides alternating current
to the outlet.
There are two primary types of outlets:
domestic and industrial.
While not obvious from looking at them, the
two sides of an electrical outlet represent part
of a 'loop of wire' and plugging an electrical
device into that outlet completes that loop,
which allows electricity to flow through the
device so it can operate.
 Wall switches are specifically designed to
operate on line voltage and fit inside standard
electrical boxes. They are standard items in
residential and commercial construction. A
variety of decorator or designer styles can set
these switches apart from industrial switches
where aesthetics are less of a concern.
Types of Electrical Outlets
STANDARD OUTLETS
-Chances are, standard outlets are the ones you
see scattered about your home and office. You
can plug in just about any small appliance to
them (TV, computer, hair dryer, toaster)
because they supply a basic 120 volts of
electricity.
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NON-POLARIZED OUTLETS
If your home is very old, you
might have outlets that are
not only ungrounded but
non-polarized as well. You
can tell that they’re nonpolarized because the pins
are the same size and the
receptacle is symmetrical. It’s very uncommon
to see non-polarized outlets today because
they’re very unsafe. Polarization reduces the
risk of electrical shock, so if you have
nonpolarized outlets, you need to have them
replaced right away.
receptacle (bottom photo) comes with four pins
so that it can supply 240 volts of electricity.
Some homes have dryer receptacles with three
pins, but these are fading out because new
homes are required to be built with four-pin
dryer receptacles.
USB OUTLETS
GFCI OUTLETS
In rooms that sometimes get wet (kitchens,
bathrooms, garages), you will usually find GFCI
(ground fault circuit interrupter) outlets. GFCI
outlets can be identified by two special buttons
in the centre—one black and one red. They
contain a circuit breaker so that if water
tampers with the outlet, the receptacle will turn
itself off without shutting off electricity in the
rest of the house. You can use the black button
to test the outlet and the red button to reset it.
RANGE OUTLETS AND DRYER OUTLETS
Some appliances in your house require too
much power to work with standard outlets. A
range outlet (top photo) provides electricity
specifically to your cooking range and is
attached to its own circuit breaker. A dryer
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Finally, you may soon start to see
standard outlets fitted with two extra holes—
USB charging ports. These USB outlets allow
homeowners to plug in items that are charged
using a USB connector, like cell phones and
MP3 players. They’re very convenient if you’re
not near a computer, but they’re still quite rare.
LAMP HOLDERS
 The device which holds a light bulb or lamp.
It’s important that the lamp holder is
compatible with the type of bulb we want to
use, with the wrong base selection will not fit in
the lamp or fixture.
 The “B” refers to the style of Base which is a
Bayonet, and the 22 means it has a 22 mm base
width.
Application: All Regular type of Bulbs including
specialist low voltage halogen lamps.
EDISON SCREW CAP(E/ES)
 Light bulb sockets are normally defined by a
letter-numberletter (Third Letter is optional). 
The first letter indicates the shape of the base.
 The Second numbers indicates either the
width of the base or the distance between the
pins.
 Named as inventor Thomas Edison, the Edison
Screw or “ES” lamp fitting is used in a vast range
of applications.
 The Third Letter indicates the number of pins
or contacts on the lamp. The numbers are
normally in millimeters.
 Type of Connection: “Screw” Action
DIFFERENT TYPES OF SOCKET AVAILABLE IN
MARKET:
 Bayonet Cap Base (B)
 Edison Screw Cap Base (E)
 Single Pin Type Base (F)
 Bi Pin or Multi Pin Type (G)
 Cable Connections (K)
 Pre- focused Light Base (P)
 Recessed Contact Base (R)
 Flange Base Light Bulb Base (F or T)
 Pin Configuration: (Exx or ESxx):
 The First letter indicates the shape or Style of
the base.
 The Second number indicates the width of the
base (normally in millimeters).
Example: E26 base.
 The “E” refers to the style which is an Edison
screw-in, and the 26 means it has a 26 mm base
width.
Application: Large chandeliers Some Decorative
Lamps.
 The most commonly used screw fittings are
shown in the table below. Other, less frequently
used, sizes include E11, E17 and E26
 Slide Base (S)
 Wedge Base (W)
 Special Type Light bulb Base (X)
Bayonet Cap Base (B/BC/SBC)
LAMP HOLDERS
 Type of Connection: “push and twist” action
 Pin Configuration: (Bxx or BCxx):
 The First letter indicates the shape or Style of
the base.
 The Second number indicates the width of
the base (normally in millimeters).
Example:
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-FLUSH TYPE
-SURFACE TYPE
-HANGING
1. CHAIN
2. WEATHER
Understanding Electrical Cable

Metallic Sheathed Cable
Also known as armored or BX
cables, metal-sheathed cables are
often used to supply mains
electricity or for large appliances.
They feature three plain stranded
copper wires (one wire for the
current, one grounding wire and
one neutral wire) that are insulated
with cross-linked polyethylene, PVC
bedding and a black PVC sheathing.
BX cables with steel wire sheathing
are often used for outdoor
applications and high-stress
installations

Multi-Conductor Cable
This is a cable type that is
commonly used in homes, since it is
simple to use and well-insulated.
Multi-conductor or multi-core (MC)
cables feature more than one
conductor, each of which is
insulated individually. In addition,
an outer insulation layer is added
for extra security. Different
varieties are used in industries, like
the audio multicore ‘snake cable’
used in the music industry.

Coaxial Cable
A coaxial (sometimes heliax) cable
features a tubular insulating layer
that protects an inner conductor
which is further surrounded by a
tubular conducting shield, and
might also feature an outer sheath
for extra insulation. Called ‘coaxial’
since the two inner shields share
the same geometric axis, these
cables are normally used for
carrying television signals and
connecting video equipment.
An electrical cable also has different types, color
and application as its determining factors.
1. Types of Electrical Cables
There are more than 20 different types of
cables available today, designed for applications
ranging from transmission to heavy industrial
use. Some of the most commonly-used ones
include:



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Non-Metallic Sheathed Cable
These cables are also known as
non-metallic building wire or NM
cables. They feature a flexible
plastic jacket with two to four wires
(TECK cables are covered with
thermoplastic insulation) and a bare
wire for grounding. Special varieties
of this cable are used for
underground or outdoor use, but
NM-B and NM-C non-metallic
sheathed cables are the most
common form of indoor residential
cabling.
Underground Feeder Cable
These cables are quite similar to
NM cables, but instead of each wire
being individually wrapped in
thermoplastic, wires are grouped
together and embedded in the
flexible material. Available in a
variety of gauge sizes, UF cables are
often used for outdoor lighting and
in-ground applications. Their high
water-resistance makes them ideal
for damp areas like gardens as well
as open-to-air lamps, pumps, etc.



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Unshielded Twisted Pair Cable
Like the name suggests, this type
consists of two wires that are
twisted together. The individual
wires are not insulated, which
makes this cable perfect for signal
transmission and video
applications. Since they are more
affordable than coaxial or optical
fiber cables, UTP cables are often
used in telephones, security
cameras and data networks. For
indoor use, UTP cables with copper
wires or solid copper cores are a
popular choice, since they are
flexible and can be easily bent for
in-wall installation.

Twin-Lead Cable
These are flat two-wire cables that
are used for transmission between
an antenna and receiver, like TV
and radio.

Twinaxial Cable
This is a variant of coaxial cables,
which features two inner
conductors instead of one and is
used for very-short-range highspeed signals.
Ribbon Cable
Ribbon cables are often used in
computers and peripherals, with
various conducting wires that run
parallel to each other on a flat
plane, leading to a visual
resemblance to flat ribbons. These
cables are quite flexible and can
only handle low voltage
applications.
Direct-Buried Cable
Also known as DBCs, these cables
are specially-designed coaxial or
bundled fiber-optic cables, which
do not require any added
sheathing, insulation or piping
before being buried underground.
They feature a heavy metal core
with many layers of banded metal
sheathing, heavy rubber coverings,
shock-absorbing gel and waterproof
wrapped thread-fortified tape. High
tolerance to temperature changes,
moisture and other environmental
factors makes them a popular
choice for transmission or
communication requirements.

Paired Cable
With two individually insulated
conductors, this cable is normally
used in DC or low-frequency AC
applications.

Twisted Pair
This cable is similar to paired
cables, but the inner insulated wires
are twisted or intertwined.
2. Cable Color Code
Color coding of cable insulation is done
to determine active, neutral and earth
conductors. The NEC has not prescribed
any color for phase/active conductors.
Different countries/regions have
different cable color coding, and it is
essential to know what is applicable in
your region. However, active
conductors cannot be green/yellow,
green, yellow, light blue or black.
Cable Size
Cable size is the gauge of individual
wires within the cable, such as 14, 12, 10 etc. –
again, the bigger the number, the smaller the
size. The number of wires follows the wiregauge on a cable. So, 10/3 would indicate the
presence of 3 wires of 10-gauge within the
cable. Ground wire, if present, is not indicated
by this number, and is represented by the letter
‘G’.
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CONTENT
ELECTRICAL SYSTEMS
1
ELECTRICAL WIRE AND CABLES
2
TYPE OF SWITCHES
4
TYPE OF ELECTRICAL OUTLETS
7
TYPE OF LAMPHOLDER
9
UNDERSTANDING ELECTRICAL CABLE
10
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