Perform roughing-in activities, wiring and cabling works for single-phase distribution, power, lighting and auxiliary systems

WEB SCRIPT ELECTRICAL INSTALLATION AND MAINTENANCE NC II
Sector
Qualification: ELECTRONICS AND ELECTRICAL
Unit of
Competency: ELECTRICAL INSTALLATION AND MAINTENANCE NC II
Learning PERFORM ROUGHING-IN ACTIVITIES,WIRING AND CABLING WORKS FOR SINGLE-
Outcomes: PHASE DISTRIBUTION,POWER,LIGHTING AND AUXILIARY SYSTEMS
Developer/s:
Install Auxiliary Terminal Cabinet and Distribution Panel
OBJECTIVES
Michael P. De Sena

At the end of this unit, you should be able to:

 Identify the different types of distribution panel
 Identify the different types of building auxiliary system
 Identify the different types and uses of circuit breakers
 Identify the different types of wiring color coding use in circuit breaker panel installation
 Understanding different parts of circuit breaker panel
 Understanding the procedure/steps on installation of electrical distribution board

Installing Auxiliary Terminal Cabinet and Distribution Panel

LESSON 1

TOPIC 1 Auxiliary Terminal Cabinet and Distribution Panel-Types,Uses and Purpose
Topic 2
 Building projects requires MV Distribution Panel-boards for distribution of power to each utilities. A good
electrical distribution network will have proper design, right components, and future load provisions. Space
utilization will also be an important factor for maintenance and handling of the equipment's.

Auxiliary Terminal Cabinet

 A switchboard (or a cubicle) on which are fixed the devices necessary to control, to protect and to distribute
auxiliary ac and dc supplies within a substation

Types of Building Auxiliary System (may include the following)

 Close Circuit Television System
 Fire Alarm System
 CATV/MATV System
 Lighting Control
 Background Music and public Address

Type Description

Close Circuit CCTV is a ubiquitous feature of
Television System institutional security systems. It is
employed by prisons, banks, urban
police forces, airports, military
organizations, utilities, large
corporations, various other
organizations, and wealthy
individuals. Examples include: X ray
baggage-inspection devices at
airports.

Fire Alarm System A fire alarm is a unit made of several
devices, which uses visual and audio

signalization to warn people about a

possible fire, smoke, or carbon
monoxide occurrence in the area of

coverage. Fire alarms are usually set
in fire alarm systems to provide
zonal coverage for residences and

commercial buildings

CATV/MATV System Distribution of program content within
your facility can be accomplished
using Community Antenna / Master
Antenna / Satellite Master Antenna
/ Internet Protocol (CATV / MATV /
SMATV / IPTV) distribution systems
designed and installed by Electronic
Contracting Company. You can
distribute cable, satellite, digital
program materials, on demand
content, and information channels
throughout your facility.

Lighting Control A lighting control system is an
intelligent network based lighting
control solution that incorporates
communication between various

system inputs and outputs related to
lighting control with the use of one or
more central computing devices.
Lighting control systems are widely

used on both indoor and outdoor
lighting of commercial, industrial, and
residential spaces.

Background Music A public address system (PA system)
and public Address is an electronic sound amplification
and distribution system with a
microphone, amplifier and
loudspeakers, used to allow a person
to address a large public.

Distribution Panel

Topic 3:

Sub-Topic 3.1  Is a safe system designed for house or building that included protective devices, isolator switches, circuit
breaker and fuses to connect safely the cables and wires to the sub circuits and final sub circuits including
their associated Live (Phase) Neutral and Earth conductors. Distribution board is also known as “Fuse
Board“, “Panel Board” or “Consumer Unit“.

Types of Distribution Panel

 Main Distribution Board (MDB)

 Sub Distribution Board (SDB)

 Final Distribution Board (FDB)

Type Description

Main Distribution  A distribution board unit installed in
Board (MDB) the buildings which firstly receive
the incoming single phase
electric supply (AC low voltage Electricveda.com
(LV) (230V AC or 120V AC in
US) from transformer secondary
through electric pole and energy
meter or the distribution
company’s electric service

provider outlets is known as
Main Distribution Board.
 Main Distribution Board (MDB) is
also known as Fuse board or
consumer unit where the main
protective and isolation devices
are installed to provide electricity
in a safe range to the connected
electrical appliances.

Sub Distribution  Sub-Main Distribution Boards. ...
Board (SDB) These are the switchboards that
although similar construction, are
Final Distribution larger than a final distribution
Board (FDB) board circuit.

 The boards are installed midway
through the power distribution
system, at the point in a large
distribution cable ends, and
several smaller starting sub-
circuits.

 FDB Electrical – manufacturers of
earth leakage Residual Current
Devices (RCD) and Earth
Monitoring (ECM, PCLM, ERM)
and suppliers of MCCB over-
current and short circuit
protection technology products.
These include protective
electrical devices under the
Optima brand.

 The final switches are used to
control the connected electrical
devices and appliances such as

light, air-conditioner, fan etc.

Wiring Accessories for Single Phase Distribution Board

Sub-Topic  Main Distribution Board or Fuse Boards (Consumer Unit) usually contains on the following units to control and
3.2: distribute electric supply to the different connected appliances and devices through electrical wiring cables and
wires.

Type Description

Molded Case Circuit  Rated between 10A to
Breaker(MCCB) 2,500A

Miniature Circuit  Tripping current can be
Breaker(MCB)
adjusted

 Interrupting capacity 10 –

200 kVA

 Used for high power

requirements

 It is another type of
electrical protection device

which is used when load

current exceeds the limit of
a miniature circuit breaker.
 MCCB provides protection
against overload, short

circuit faults and is also
used for switching the
circuits.

https://www.google.com/search?clie
nt=firefox-b-
d&q=molded+case+circuit+breaker+
%28mccb%29

 Rated below 100A
 Tripping current is fixed
 Interrupting capacity under 10

kVA
 Used for low energy

requirements
 Miniature circuit breaker

(MCB) automatically switches
off electrical circuit during an
abnormal condition of the
network means in overload
condition as well as faulty
condition.
 Nowadays we use an MCB in
low voltage electrical network
instead of a fuse.

https://www.google.com/search?cl
ient=firefox-b-
d&q=miniature+circuit+breaker+%
28mcb%29

Residual Current  A Residual Current Circuit
Circuit Breaker Breakers is another different
(RCCB) class of Circuit Breakers. A
Residual Current Circuit
Breaker (RCCB) is essentially
a current sensing device used
to protect a low voltage circuit
in case of a fault.

 It contains a switch device that
switches off whenever a fault
occurs in the connected circuit.

http://engineering.electrical-
equipment.org/electrical-
distribution/residual-current-
circuit-breaker-rccb.html

Earth leakage Relay  Earth Leakage relays (ELR's)
or also known as ground fault
ELCB (Earth relays are residual current
Leakage Circuit monitors (RCM's) that are used
Breaker) to detect potentially dangerous
ground fault currents before
they cause any hazard.
Causes for ground fault
currents: Inadequate insulation
due to mechanical damage of
cables and devices.

https://www.google.com/search?cl
ient=firefox-b-
d&q=earth+leakage+relay

 Phase (line), Neutral and Earth
wire connected through ELCB.

 ELCB is working based on
Earth leakage current.

http://www.neweysonline.co.uk/ne
weys/pdf/Schneider_Electric_C60
H_MCBs_Technical.pdf

Sub-Topic Electrical Cable and Wire Color Markings
3.3:
Purpose: To become familiar of basic wiring color code use in installation of distribution board

Type Description
Black Wires: Hot
 Black insulation is always used
for hot wires and is common in
most standard household
circuits.

 The term "hot" is used for
source wires that carry power
from the electric service panel
to a destination, such as a light
or an outlet. Even though you
are permitted to use a white
wire as a hot wire by marking it
with electrical tape, the
opposite is not recommended
or allowed. In other words, do
not use a black wire as a
neutral or ground wire, or for
any purpose other than for
carrying live electrical loads.

Red Wires: Hot  Red wires are used to
designate hot wires.

 Red wires are sometimes used
as the second hot wire in 240-
volt installations. Another
useful application for red wires
is to interconnect hardwired
smoke detectors so that if one
alarm is triggered all of the
others go off simultaneously.

White Wires With  When a white wire
Black or Red is augmented with a red or
Tape: Hot black color marking, this often
indicates that it is being used
as a hot wire rather than a
neutral wire. Typically, this is
indicated with a band of black

Bare Copper or red electrical tape (but other
Wires: Ground colors may be used) wrapped
around the wire's insulation.
Green Wires:  For instance, a white wire in a
Ground two-wire cable may be used for
the second hot wire on a 240-
volt appliance or outlet circuit.
This white wire should be
looped several times around
with black electrical tape to
show that it is being used for
something other than a neutral.

 Bare copper wires are the most
common type of wire used for
grounding.

 All electrical devices must be
grounded. In the event of a
fault, grounding provides a safe
pathway for electricity to travel.
The current passes back to the
ground or earth. Bare copper
wires connect to electrical
devices, such as switches,
outlets, and fixtures, as well as
metal appliance frames or
housings. Metal electrical
boxes also need ground
connection because they are
made of a conductive material.
Plastic boxes are
nonconductive and do not need
to be grounded.

 Green insulated wires are
sometimes used for grounding.

 Ground screws on electrical
devices are often painted
green, too. Never use a green
wire for any purpose other than
for grounding.

White or Gray  White or gray indicates a
Wires: Neutral neutral wire.

 When examining a white or
gray wire, make certain that it
has not been wrapped in
electrical tape. This would
indicate a hot wire. Older wires
sometimes may lose their
electrical tape wrapping. So, if
the box has a loose loop of
tape inside of it, there is the
possibility that it may have
come off of the neutral wire.

 The term neutral can be
dangerously deceiving as it
appears to imply a non-
electrified wire. It is important
to note that neutral wires may
also be carrying power and can
shock you. While wires

designated as hot (black or red
insulated wires) carry power
from the service panel (breaker
box) to the device, neutral
wires carry power back to the
service panel. Thus, both hot
and neutral wires have the
potential to shock and injure
you.

Blue and Yellow  Blue and yellow wires are
Wires sometimes used as hot wires
inside an electrical conduit.

What's Inside the Circuit Breaker Panel

 The Main Breaker

 The Branch Circuit Breakers

 Hot Bus Bars

 Main Bonding Jumper

 Ground Bus Bar

 Neutral Bus Bar

Type Description

The Main  The main circuit breaker is a
Breaker large breaker usually located at
the top of the panel but
Topic 4: sometimes near the bottom or
along one side. It controls all
the power of the branch circuit
breakers (the breakers
controlling individual circuits) in
the panel.

 Power comes from the utility
service lines, flows through the
electrical meter on the outside
of your house, and continues
into the service panel.
However, some systems
include a separate disconnect
switch between the meter and
the panel. The main breaker is
used to turn power to all the
branch circuits ON or OFF at
the same time.

 The main circuit breaker also
identifies the total amperage
capacity of the service panel
and will have a number on it
identifying its amp capacity,
such as 100, 150, or 200. The
standard for new panels today
is 200 amps, but panels can
have an even higher capacity

Warning: The main circuit
breaker shuts off the power to all

of the branch circuits but does
not shut off the power from the
utility. The utility service lines and

The Branch the terminals they connect to
Circuit Breakers inside the panel remain live
(carrying deadly electrical
current) unless the utility
company shuts off the service to
the home

 The breakers in the two rows
are primarily for branch circuits.
These include the 15-amp

circuits that feed the regular
lighting and outlet circuits and
the 20-amp circuits that supply
outlets in the kitchen, garage,

and other areas, as well as
some appliances. Large
breakers that provide 30, 40, or
50 amps are double-pole

breakers that have double-size
levers.

Hot Bus Bar  The two thick, black service
wires feeding the main circuit
breaker each carry 120/240
volts from the electric meter
and feed the two "hot" bus bars
in the panel.

Main Bonding https://www.google.com/search?q
Jumper =main+bonding+jumper+size

 The main bonding jumper
provides a ground connection
between the neutral/ground
bus and the service panel.
Another ground connection is
made by the grounding
electrode conductor or GEC.

 This is a bare copper wire that
connects the neutral/ground
bus bar to a ground rod driven
into the earth near the service
panel or to metal rebar in the
home's foundation.

 This final ground connection
with the earth allows stray
electrical current (such as a
surge created by lightning) to
pass safely into the
surrounding soil

https://www.google.com/search?q
=main+bonding+jumper+size

Ground Bus Bar  Some service panels have a
separate bus bar for ground-
wire connections, instead of a
neutral/ground bus. In this
case, the ground bus is
electrically connected to the
neutral bus in main service
panels only; in subpanels, the
ground bus and neutral bus are
not connected to each other.

https://www.google.com/search?q
=ground+bus+bar

Neutral Bus Bar  In many service panels, the
neutral bus bar also serves as
the grounding bus bar and is
where the individual bare
copper circuit ground wires are
terminated. In this case, it is
often referred to as a
neutral/ground bus bar.

TOPIC 5: How to Install Electrical Distribution Board

 The neutral is also further distributed to various sides from the neutral link. One or two spare sub circuits of the
same capacity should be provided on each distribution board and branch distribution board for future
requirement.

 The current rating of circuit, size of fuse element and detail of circuits controlled by each distribution board
should also be marked.

 Strip the wire only enough to make the connection to the main breaker terminal lugs. The black and red wires
are the feeder wires in this photo with the black wires being one of the hot feeds and the red wires being the

other.

Steps to Install electrical distribution board

 You must have to install the feeder pipe at first.
 Install the connector into the panel
 If you’re using metal pipe, place a plastic bushing over the connector threads.
 Level the panel and insert screws through the holes provided in the back of the panel
 Using a tape, pull the electrical feeder wires through the feeder pipe.
 Leave enough wire to get to the opposite side of the panel.
 Bend the two black wires to shape them for easy installation to the main breaker.
 Excess bare wire leaves a safety hazard where the wires can come in contact with other wires and cause a

short circuit.
 Connect the neutral wire to the neutral buss. The neutral buss is located on either side of the breakers. It is a

silver-colored bar with many smaller screws and connection points
 Connect all of the green and bare copper wires to the ground buss bar.
 If you bend the wires ahead of time, you’ll have a nice, neat wire installation that looks uniform.
 Next, install the circuit feeds to the branch circuit breakers.
 Connect the appropriate sized wire to the correctly rated breaker. Bend the wires so that they keep a neat

appearance when the installation is complete.

http://www.electricalpowerenergy.com

https://www.youtubecom/watch?v=8T7HMUGEiOA