CONSTRUCTION SERVICES

1. Electrical Installation &
Maintenance

2. Electricity

3. Benjamin Franklin
Father of Electricity
Kite experiment (one stormy
night in Philadelphia) In
1752
Electricity
had positive and negative el
ements

4. Thomas Edison
Electric light bulb
(perfected his
invention)
Direct current
(DC) electricity
(1879)

5. Nikola Tesla
Alternating
current (AC)
electricity
Father of
AC

6. Electricity
 Electricity is the flow of electrical power or charge
 It is a secondary energy source
 Electro-magnetic conversion
 such as a wire, inside a magnetic field
 generator connected to a turbine
 turbine provides the motion required to move the
conductor in the generator.
 Chemical reaction

7. Electricity
 Primary sources
 Coal
 Natural gas
 Oil
 Nuclear power
 Hydropower
 Geothermal Energy
 Biomass
 Ocean Power
 Solar Energy

8. Resistance
Opposition that
a substance
offers to the
flow of
electric current

9. Resistance
The standard unit
of resistance is
the ohm, (Greek
letter Omega (Ω).
Represented by
the uppercase
letter R.

10. Resistance
 The higher the resistance, the lower the current flow. If
abnormally high, one possible cause (among many) could be
damaged conductors due to burning or corrosion. All
conductors give off some degree of heat, so overheating is an
issue often associated with resistance.
 The lower the resistance, the higher the current flow. Possible
causes: insulators damaged by moisture or overheating.

11. George Ohm

12. Volt
Electrical Pressure that
causes the electron to
move through a conductor
Electromotive Force (EMF)
Presented by letter V or E

13. Alessandro Giuseppe
Antonio Anastasio Volta

14. Ampere
 Base unit of electric current in
the International System of
Units (SI). It is named after André-
Marie Ampère (1775–1836),
 An ampere is the unit used to
measure electric current. Current is a
count of the number of electrons
flowing through a circuit.
 How fast an electric current flows is
an example of an ampere.

15. André-Marie Ampère (1775–1836),

16. Watt
The basic unit of electric,
Unit of power (W)
The watt is a measure of
how much power is
released
Power consumed

17. James Watt

18. Classification of Electric Current
Direct Current ( DC )
Alternating Current ( AC )

19. Direct Current ( DC )
Current can only
flow in one
direction, flow
steadily in a single
direction, or
"forward”

20. Alternating Current ( AC )
Electrons keep switching
directions, sometimes
going "forward" and
then going "backward.“
Flows on multi-path
simultaneously

21. Wires and Cables

22. Conductors & Insulators
Conductors: Materials that offer very little
resistance where electrons can move easily.
Examples: silver, copper, gold and aluminum.
Insulators: Materials that present high resistance
and restrict the flow of electrons. Examples:
Rubber, paper, glass, wood and plastic.

23. Conductors & Insulators

24. Conductors & Insulators

25. Wire
Stranded
Wire
(mm2)
Solid Wire
(mm)

26. Solid Wire
 A single conductor
that is either bare or
insulated by a
protective colored
sheath. It offers low
resistance and are
perfect for use in
higher frequencies

27. Stranded Wire
 Stranded wires are used where flexibility is important because
which the wire can be used for a longer period. This type of
wire have larger cross-sectional area than solid wires for the
same current carrying capacity.

28. Stranded Wire

29. Stranded Wire
 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

30. Stranded Wire
 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

31. Triplex Wires
Triplex Wires : Triplex wires are usually used in single-
phase 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.

32. Triplex Wires

33. Main Feeder Wires
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.

34. Main Feeder Wires

35. Panel Feed Wires
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.

36. Panel Feed Wires

37. Non-Metallic Sheathed Wires
Non-Metallic Sheathed Wires : Non-metallic 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.

38. Non-Metallic Sheathed Wires

39. Single Strand Wires
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.

40. Single Strand Wires

41. Service Drop Wire (DUPLEX)
 Overhead electrical line running from a utility pole, to a
customer's building or other premises. It is the point
where electric utilities provide power to their customers
 At the customer's premises, the wires usually enter the building
through a weatherhead that protects against entry of rain and
snow, and drop down through conduit to an electric
meter which measures and records the power used for billing
purposes, then enters the main service panel

42. Service Drop Wire (DUPLEX)

43. Wires
 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.
 Philippine Electrical Code : ‘ HOT wire is always the Dark (Color) one.

44. Cable
Wire is a single
electrical
conductor,
whereas a cable
is a group of
wires swathed in
sheathing.

45. Different Classification of Wires &
Cables
Twisted pair cable – A twisted pair cable has two
cables that are twisted across each other. Twisting
can avoid noise that produced by magnetic
coupling, so this type of cable is best suited for
carrying signals. It is generally used in
telecommunication and data communication.

46. Twisted pair cable

47. Multi-conductor cable
Multi-conductor cable – Multi conductor cable has two or
more conductors that are insulated from each other. Their
purpose is to protect signal integrity by reducing hum,
noise and crosstalk. Applications include computers,
communications, instrumentation, sound, control, audio,
and data transmission. Both multi conductor and twisted
pair cables are called balanced line configuration cables.

48. Multi-conductor cable

49. Coaxial cable
 Coaxial cable – Coaxial cable is composed of an inner solid
conductor surrounded by a paralleled outer foil conductor that
is protected by an insulating layer. The two conductors are
separated from each other by an insulating dielectric. Coaxial
cables are generally used in TV Cable. It is called an
unbalanced line as the signal on the two conductors is not
same, which result in interference but the performance is more
stable than a twisted pair cable.

50. Coaxial cable

51. Fiber optics cable
Fiber optics cable – This kind of cable transmits signals
by a bundle of glass threads. Fiber optic cables have a
much greater bandwidth than metal cables, which
means they can carry more data. They are also less
susceptible to interference. For these two reasons, fiber
optic cables are increasingly being used instead of
traditional copper cables despite that they are
expensive.

52. Fiber optics cable

53. Splices & Joints

54. Splices & Joints
The connections must be well made and the wires
tightly joined to prevent a loss of voltage to the device
powered. In high current situations a poor connection
causes heat at the connection and oxidiation of the
wires and no more or intermittent connections.
Most problems in electrical is not a short but: an open
connection.

55. Kinds of Splices
Western Union Splice
Tap joint
Fixture splices, or fixture joints
Rat-tail splice, Twist splice, Pig-tail splice
Britannia Splice
A Through Fixture joint
Wrapped Tap

56. Western Union Splice
The Western Union splice works best to splice together
small, solid conductors. It is the most common type of
wire splice. To make the Western Union splice, first
remove about five inches of insulation from both wires
and cross the exposed wires. Wrap one wire around the
other five or six times, and then do the same with the
other. Cut the excess wires off and pinch the ends down
with pliers.

57. Western Union Splice
 This is the most widely used
splice or joint in interior
wiring installation to extend
the length of wire from one
point to another.
 Used extensively for outside
wiring to extend the length
of wire from one end to
another.

58. Tap splice or Tap joint
 Used to connect a conductor to a running wire. To make a tap
splice, strip about 1½ inches off the running wire. Take the
connecting wire and wrap it once around the running wire.
Now wrap the end of the wire through the loop you just made.
Then wrap the connecting wire around the running wire about
six times. Make sure the wire points away from the original turn.
Solder the joint and wrap tape around it.

59. Tap splice or Tap joint
This is used
where the tap
wire is under
considerable
tensile stress
circuit

60. Fixture splices, or fixture joints
 Used to connect wires of different sizes. This joint requires five inches of
insulation stripped off the wire. Hold the wires together and then twist
them a few times with a pair of pliers. Both wires must twist for the joint
to be tight. Cut both ends of wire so that they are the same length, and
then take the twisted joint and bend it so that it lines up with the wires.
Take the cut ends and extend them perpendicular to the wire and the
twisted portion. Wrap these two ends in the same direction as the twist.
Solder the joint together and wrap tape around it.

61. Fixture splices, or fixture joints

62. Britannia Splice
 Britannia Splice, also known as a
cable spice, is not easy or neither
difficult in doing. This splice is
applied on both inside and outside
of the building to big solid wire
where twisting is difficult but there
is an equipment to lessen the
difficulty on doing this kind of
splice.

63. Rat-tail splice/Twist splice/Pig-tail splice
Very basic electrical splice that can be done with
both solid stranded wire. It is made by taking two
or more bare wires of the same diameter and
wrapping them together symmetrically around
each a common axis. The bare splice can be
insulated with electrical tape or other means.

64. Rat-tail splice/Twist splice/Pig-tail splice
 commonly used to join two or
more • conductors inside the
junction box. It is • suitable for
service where there is no •
mechanical stress when wires
are to be • connected in an
outlet box, switch, or •
conduit fitting

65. Wrapped Tap/ Tee Joint
 Used on large solid conductors where is difficult to wrap the
heavy tap wire around the main wire. When a No. 6 AGW wire
is used, both the main wire and the tap wire are skinned about
4 inches. The tap wire is bent into an L shape about ½ inches
from the insulation so that it will rest along the side of the main
wire. A wrapping wire is then prepared using size No. 18 bare
conductors terminating beyond the bent of tap wire and up to
the installation of the main conductor.

66. Wrapped Tap/ Tee Joint

67. Through Fixture Joint
 Used where fixtures are connected to branch wires at an
intermediate point. In making this joint, the end of one
conductor is skinned about 2 inches and the other about 4
inches. At a point ¼ inches away from the insulation of the
longer wire, three or four long twists are made similar to the
rat-tail joint. The long bared portion of the long wire is bent
over parallel with the free ends. Both free ends are then place
alongside each other wrapped together around the straight
bared portion.

68. Through Fixture Joint

69. Common Splices and Joints
Demonstration
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70. Circuit
Path in
which electrons from
a voltage or current s
ource flow

71. Types Of Electrical Circuit
Series Circuit
Parallel Circuit

72. Series Circuit
 Only one path for electricity to flow from one point to another.
The amount of electricity in the circuit is consistent throughout
any component in the circuit. When electricity flows through a
series circuit, its rate of flow (speed) will never fluctuate. The
total resistance of a series circuit equals the sum of individual
resistances. The more resistors that a series circuit has, the
more difficult it is for electrons to flow.

73. Series Circuit

74. Parallel Circuit
 Has multiple paths for electricity to flow from one point to
another. According to website All About Circuits, “all
components are connected between the same set of electrically
common points.” Often, resistors and sources will be connected
between two sets of electrically common points. In a parallel
circuit, electricity can flow in multiple directions horizontally and
vertically. The components of a parallel circuit will have the
same voltage across their ends and will have identical polarities.

75. Parallel Circuit

76. Parallel Circuit

77. Difference between Series
and Parallel Circuit
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78. Series-Parallel Circuit
Properties of both series and parallel circuits can be
combined to form a specialized series-parallel circuit, in
which the wires or components are configured such that
there are only two loops through which electricity can
flow. Like series circuits, the electricity has a path to
which it must adhere. Like parallel circuits, the circuit still
has two sets of electrically common points.

79. Series-Parallel Circuit

80. Difference between Parallel and
Series Circuit

81. Raceway
A raceway (sometimes referred to as a raceway
system) is an enclosed conduit that forms a
physical pathway for electrical wiring. Raceways
protect wires and cables from heat, humidity,
corrosion, water intrusion and general physical
threats

82. Raceway

83. Types of Raceway
Metal Raceway
Non-Metal Raceway

84. Metal Raceways
Cable Trays
Conduit

85. Metal Raceways

86. Non-Metal Raceway
Cable Trays
Conduit

87. Non-Metal Raceway

88. Cable Tray
Manage all these wires
Separate power wiring and data/communication
cabling, a single, large cable tray installation is capable
of routing a large amount of wiring

89. Cable Tray
 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

90. Conduit
 In addition to the cable Articles, Chapter 3 of the NEC contains
a sequence of Articles pertaining to raceways. The Art. 100
definition of raceway indicates that it is an enclosed channel
designed expressly for holding wires, cables, or busbars.

91. Classification of Conduit Pipes
 Intermediate Metal Conduit (IMC)
 Rigid Metal Conduit (RMC)
 Rigid Steel Conduit (RSC)
 Flexible Metal Conduit (FMC)
 Liquidtight Flexible Metal Conduit (LFMC)
 Polyvinyl Chloride Conduit (PVC)
 Electrical Metallic Tubing (EMT)
 Galvanized Rigid Conduit (GRC)
 PVC conduit

92. Intermediate Metal Conduit (IMC)
 The wall thickness of IMC is less than that of RMC, so it has more
interior room for conductors.
 IMC is lighter and less expensive than rigid metal conduit
 Though IMC has thinner walls than RMC, IMC is actually the
stronger of the two — because of the steel alloy used to make it.
 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.

93. Intermediate Metal Conduit (IMC)

94. Rigid Metal Conduit (RMC)/Rigid
Steel Conduit (RSC)
 RMCs and RSCs are your heaviest and thickest option, typically made of
coated steel, stainless steel, red brass, or aluminum. These pipes can be
installed above ground or underground. They are similar in appearance to
metal water pipes and are threaded at both ends.
 Rigid metal conduit, or RMC & RSC, is heavy-duty galvanized steel tubing that
is installed with threaded fittings. It is typically used outdoors
 Heaviest-weight and thickest wall conduit. Where galvanized by the hot-dip
process, it has a coating of zinc on both the inside and outside. Electro-
galvanized rigid conduit has a coating of zinc on the exterior only, with
approved corrosion resistant.

95. Rigid Metal Conduit (RMC)/Rigid
Steel Conduit (RSC)

96. Flexible Metal Conduit (FMC)
 This is your best option for areas that need to sustain large
amounts of movement and vibration. They are found in stainless
steel, galvanized steel, or aluminum. They can be waterproof if
needed and are installed above ground. The appearance is similar
to that of metallic armored cable.
 Flexible metal conduit (FMC), commonly called “Greenfield” or
“flex,” is a raceway of an interlocked spiral metal strip. Equipment
that moves, shakes, or vibrates. Examples of such equipment
include pump motors and industrial machinery.

97. Flexible Metal Conduit (FMC)

98. Liquid tight Flexible Metal
Conduit (LFMC)
 Where vibration or frequent relocation is an issue, LFMC is often the
solution for connecting the equipment. LFMC is of similar
construction to FMC, but also has an outer liquidtight thermoplastic
covering to provide protection from moisture and some corrosives.
 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.

99. Liquid tight Flexible Metal
Conduit (LFMC)

100. Polyvinyl Chloride Conduit (PVC)
 PVC is made from a combination of plastic and vinyl. PVC pipes can be
installed above ground, underground, or encased in cement. PVCs are most
commonly used underground. These pipes are lightweight, flexible, impact-
resistant, non-conductive, ultraviolet-resistant, and corrosion-resistant.
 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.

101. Polyvinyl Chloride Conduit (PVC)

102. Electrical Metallic Tubing (EMT)
 Sometimes called thin-wall, is commonly used instead of galvanized rigid conduit
(GRC), as it is less costly and lighter than GRC. EMT itself is not threaded, but can be
used with threaded fittings that clamp to it. Lengths of conduit are connected to each
other and to equipment with clamp-type fittings. Like GRC, EMT is more common in
commercial and industrial buildings than in residential applications. EMT is generally
made of coated steel, though it may be aluminum.
 Electrical metallic tubing (EMT) is a lightweight raceway that’s relatively easy to bend,
cut, and ream. Because it isn’t threaded, all connectors and couplings are of the
threadless type and provide quick, easy, and inexpensive installation compared to
threaded metallic conduit systems. Consequently, EMT is very popular. EMT is
manufactured in galvanized steel or aluminum; the steel type is more commonly used.

103. Electrical Metallic Tubing (EMT)

104. 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 is in need
of 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.

105. Galvanized Rigid Conduit (GRC)

107. Purpose of Electrical Conduit
To provide
means for
the runners
or wires from
one point to
another

108. Purpose of Electrical Conduit
To
physically
protect
the wires

109. Purpose of Electrical Conduit
To protect
surrounding
against the
effect of fault
in the wiring

110. Purpose of Electrical Conduit
To protect the
wiring system
from damage
by the building
and the
building
occupants

111. Purpose of Electrical Conduit
To protect the
building and
the occupants
from damage
by the electric
system

112. Outlets

113. Outlets
 A socket that connects an electrical device
to an electricity supply. In buildings,
electrical outlets are usually installed in
the wall, although they can also be
installed in the floor. Occasionally, they are
found in the ceiling for powering devices
such as garage door openers or neon
signs in storefront windows

114. Kinds of Outlets
 Ligthing Outlet (L.O)
 Convenience Outlet (C.O)
 Special Purpose Outlet (S.P.O)
 Floor Outlet (F.O)

115. Lighting Outlet
An outlet
intended for
the
connection
of a fixture
or lamp
holder

116. Convenience Outlet
 In order for electricity to
work, it needs to create a
circuit. An C.O is the
source of electrical power
you use to plug in many of
your appliances, which is
how you create that circuit
in your home.

117. Special Purpose Outlet
 Because having a grounding wire and grounded (three-pronged) outlets
adds an extra level of safety, newer houses and buildings are required to
have three-pronged outlets with grounding wires. A grounding wire is
connected separately to each outlet, and then is connected to the
bottom of the breaker box. This grounding wire neutralizes any
dangerous electrical current into the ground.
 A grounding line is used to protect your appliances from surges or
overvoltage problems. It also stabilizes voltage and protects people,
properties, and equipment from electric shock.

118. Special Purpose Outlet

119. Floor Outlet
 Because having a grounding wire and grounded (three-pronged) outlets
adds an extra level of safety, newer houses and buildings are required to
have three-pronged outlets with grounding wires. A grounding wire is
connected separately to each outlet, and then is connected to the
bottom of the breaker box. This grounding wire neutralizes any
dangerous electrical current into the ground.
 A grounding line is used to protect your appliances from surges or
overvoltage problems. It also stabilizes voltage and protects people,
properties, and equipment from electric shock.

120. Floor Outlet

121. GFCI

122. GFCI
 A Ground Fault Current Interrupter
or GFCI outlet is an extremely
sensitive outlet that monitors the
current passing through it. If there’s a
slight change in current coming back
from the equipment plugged into
the outlet, the GFCI will automatically
disconnect the circuit so the electrical
current is no longer flowing.

123. How GFCI Works
CLICK ME!!!

124. Switches