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Sri Lanka Institute of Information Technology

Report on In-Plant
Training ​
At
Sierra Construction Pvt Ltd

Name

​

​

​

​: EN14505522

Registered Number
Course

​

​

​: B
...
Engineering

​

​: Electrical Power Engineering

Field of Specialization
Period of Training

​: Weerasuriya P
...
M
...
It’s a huge company and
has many other sub companies like sierra IT, Sierra electrical, Sierra water, and Sierra road
...
I have worked in several projects of Sierra hence they changed my working site
occasionally
...
During the first phase of the internship, I worked on
wiring and lighting side
...
In addition I have worked on protection side also
...
In latter phase of the internship, I was asked to study on lighting
designing, cable selection, and transformer selection and so on
...
Later on I was assigned to do the megger testing, tests to determine soil resistivity
...


Acknowledgement
Every project big or small is successful largely due to the effort of a number of wonderful
people who have always given their valuable advice or lent a helping hand
...

i am extremely grateful to “COMPANY” for the confidence bestowed in me and entrusting
my project entitled “” with special reference to Sierra
...
Mahasen for
making the resources available at right time and providing valuable insights leading to the
successful completion of my project
...
Kalyanapala for arranging the summer training in
good schedule
...

I would also like to thank all the faculty members of SlIIT for their critical advice and
guidance without which this project would not have been possible
...


Contents
​i

Abstract

​ii

Acknowledgement

​iii

Contents
List of Figures

​vi

List of Tables

​vii
​viii

List of Equations
1
...
1
...
2
...
3
...
1
...
2
...


2
...
1
...
2
...


​Design Procedure

3
...
1 Zones

​5

3
...
1 Alarm Zone
3
...
2 Detection Zone

​5
​5

​4
​4
​5

​6

3
...
2
...
2
...
3 Detection zone configuration used

​7

3
...
Components in an addressable system

​9

4
...
1
...
Type of power outlets

​15

5
...
Ampere ratings of outlets

​15

5
...
Method of socket outlet wiring

​15

6
...
1
...
2
...
Selection of transformer
...
Selection of Generator
...
Cable selection
...
1
...

9
...
Voltage drop along the cable
...
3
...

10
...
1
...
2
...
3 Fly ash discharging system

​24

10
...
Process of sea water supply and cleaning to boiler water

​25

​26

Figure 7steam process

​27

10
...
Flue Gas desulfurization process (separate sulfur from flue gas)

​27

10
...
GGH process

​27

10
...
Turbine

​28

10
...
Generator

​28

10
...
Transformer

​28

10
...
Key facts about Coal fired electrical production
References

​30

List of Figures
Figure 1 - Management Hierarchy of CodeGen International (Pvt) Ltd
​2
Figure 2 - NTC vs PTC Thermistor characteristic difference (Source: Beckhoff Information
System (S
...
, n
...
)

​5
​6

Figure 3 - Temperature Response of USP7765

Figure 4 - Temperature Response of GE AL03006-17
...
53K-98-K Data Table

​6

List of Equations
Equation 1 - Series Resistor Selection Equation for Best Linearization

​9

viii

1
...
1
...


1
...
Company Background
SIERRA established in the year 1981, as a construction company to meet the challenges
faced in the construction industry
...

Concentrated more in to the Telecom sector and captured all major telecom engineering
projects achieving of ninety percent market share
...
Today the company has become one stop shop, in
telecom engineering field
...

With the growth of the company Sierra has ventured in to Manufacturing, Agriculture,
Leisure, IT, Electronics, Property Development areas
...
​

1
...
Management
The below diagram gives the management hierarchy of the company
...
Harsha Subasinghe
...
Dr
...


2
...


2
...
Summary of Duties
The interns at Sierra electrical are given projects to carry to by their own
...
During my 12 weeks of training, I
was told to involve in several construction projects and a cable factory that belongs to
sierra
...
In there I studied the way to put
conduits and some lack of knowledge about generators
...
There I worked on referring pcb layouts and how the circuits are
divided from the MCB to sub MCBS
...
As a result I got a over role knowledge about lighting designing , cable
selection due to the demand of the equipment uses ,how to do the Megger tester to
identified leakage current
...
Furthermore from a field visit to Lakvijaya coal power
plant, I learn the process of generating electricity from coal and how they distribute to
the total available grid capacity of SriLanka
...
2
...
There are several varieties of lighting protection systems and techniques
...
my duty was to checked the
systems state and ensure was it apply properly accompanied with the electrical engineer
...
2
...
Problem Statement
Different between the lighting conductors and arrestors
The lighting arrester is usually used in electrical transmission and distribution
...
The building was
protected against lighting by using lighting conductors
...


2
...
2
...
The Faraday
Cage principle was provide to such structures
...
To demonstrate this fact we used metal
strips to cover it on a grid pattern and all strips were earthed
...
Fire Detection and alarm system
Fire detection and alarm systems are intended for life and property protection of building
...
For example the fire detection system active fire protection system and

deactivate some systems like general lifts etc
...

Relevant Standards used
BS5839

3
...
1
...
If the only requirement is to activate all the alarm sounders to
provide a single common evacuate signal once a fire is detected
...
Then the building should be divided into alarm
zones such that all of the alarm devices in one alarm zone operate in the same way
...
1
...
The code notes that a detection zone will usually consist of an area
protected by several manual call points and/detectors, and is separately indicated to assist in
location of the fire, evacuation of the building and fire-fighting
...
This aids those
responding to the fire alarm signal, particularly the fire service
...
2 The type of system according to the technology
3
...
1 Conventional system
IN conventional systems, each detection zone is connected to the control and indicating
equipment (CIE) by a separate circuit
...
2
...


3
...

As a trainee I corporate with the site engineer and checked weather the following rules were
concerned when they put the detection zones in the building
...


1) The maximum floor area of a detection zones should be not exceed 2,000sqm
...

3) If the total floor area of a building is less than 300sqm, then the building need
only be one detection zone, regardless of number of floors
...

5) A single, vertical detection zone should be provided for fire detectors within an
enclosed stairwell, lift shaft or similar enclosed flue-like structure
...


Figure 2 – common addressable fire alarm system

3
...
Components in an addressable system
1) Control and indicating equipment
2) Repeater panels
3) Addressable decoders
4) Addressable call point
5) Addressable sounder and visual devices
6) Line isolator devices
7) Contact monitoring module
8) Output devices
9) Interface module to connect conventional lines, sounder circuits(maximum of
20 conventional detectors)
10) Fire rated wiring

The detectors that we used were depend on the different applications
Lon Pho Line Asp carb Fixe Rate
isati toel ar
irate on
d
of
on
ectri bea d
mon tem rise
smo c
m
smo oxid pera ther
Location
ke
smo smo ke
e
ture mal

flam
e

Spec
ific
fire
engi
neeri

ke

ke

ther
mal

ng

Bedrooms

√

√

ok

ok

√

ok

ok

ok

ok

Office/shops

√

√

ok

ok

√

√

ok

ok

ok

Auditoriums/clubs

x

x

x

x

√

√

ok

ok

√

Bathrooms/laundries

x

x

x

x

ok

√

x

ok

ok

Boiler/furnace room

x

x

x

x

ox

√

x

x

ok

Car parking

x

x

ok

x

xx

√

√

ok

ok

ceiling or roof voids
with access
ceiling or roof voids
difficult with access
cleaners/under stair
cupboards

ok

ok

ok

ok

ok

√

ok

ok

ok

x

x

ok

ok

x

√

ok

ok

√

x

x

x

x

x

√

√

ok

ok

cool rooms/freezers

x

x

x

ok

x

ok

√

√

Table 1 – recommended detectors for different applications

A microprocessor was used to bundles the various information with central fire alarm system

Figure 4 – The microprocessor bundles the various information and communicates with the central fire alarm system
...
Lighting Design
The equation for calculate number of luminaries for a given area
...


​

​

​

​

Lamp Type

LLD Factor

Mercury Lamps
Up to and including 700W
Over 700 W up to 1000W
Mercury Halide

0
...
7
0
...
9

Low Pressure Sodium

0
...
8
High out put
0
...
75

Blended Mercury – Tungsten

0
...
85

​

​

​

​

Table 2 - Lamp Lumen Deterioration factor table

4
...
Method of finding Utilisation Factor (UF)
Before that it is required to calculate the room index by using following equation
...
g
...

Ceiling – 70%, Wall – 50% and Floor – 30%
​Then reflectance figure will be 753
Once the room index is calculated, by using below Table Utilisation Factor (UF) can be
found
...


​

Maintenance Factor (MF): This is the ratio between the illuminance produce at the end of
maintenance and the illuminance produce at the time of installation
...
7

​

​

​

​Average – 0
...
9

Specified illuminance levels (lux) in the specification for different areas are as follows
...

Length of the Room 15 m, Width of the Room 12 m
Height of the room 3
...
8 m
Reflectance: Ceiling 70%, Wall 50% and Working Plane 30%
Luminaries Photometric data: 4 x 18 W Fluorescent with a profile louver: 8000 Lm (1450 x
4)
Required Illuminance level: 400 lux
Maintenance Factor: 0
...

Room index K = ( L x W ) / [( H1 - H0 ) x ( L + W )]

​
​

K = ( 15 x 12 ) / [(3
...
8) x (15 + 12)]

K = 3
...
0 and Reflectance = 753, the utility factor is 0
...
8 x 0
...
8)
N = 26
...
0 / (3
...
75)

​

​

​

= 1
...
4 / (3
...
75)

= 1
...

Length of the Room 11
...
0 m, Height of working Plane 0
...
80
Based on above data reflectance figure is 752
...
725 x 5 ) / [(3
...
8) x (11
...
59
From the above table for K = 1
...
63
N = (E x L x W) / ( NL x Φ x MF x UF x LLD)
N = (200 x 11
...
8 x 0
...
8)
N = 6
...

• Mark circuit arrangement on the drawing with circuit numbers

​
5
...
General purpose
...

2
...

3
...


duty

5
...
Ampere ratings of outlets

​5A, 13A, 15A – General purpose and special purpose
...
2
...
Radial circuit 2
...
5 mm sq

100 m2 maximum

Radial

20 A

2
...
0 mm sq

75 m2 maximum

Ring and Radial circuit configuration

​

​

​

​

​

Table 5 - Ring and Radial circuit configuration

Important points
Locate socket-outlets to provide reasonable sharing of the load around the ring
...

Shall not connect cookers, ovens with a rated power exceeding 2 kW
...
Load calculation
• Following loads to be calculated

​Lighting
​Power
​Equipment (Kitchen, Copy machine, etc
...
)
6
...
Demand factor (Utilization factor) – Ku:

​Demand Factor (Ku) = Maximum demand / Total connected load
6
...
Diversity Factor – Ks:

​Diversity Factor (Ks) =
Diversity occurs in an operating system because all loads connected to the System are not
operating simultaneously or are not simultaneously operating at their maximum rating
...
Selection of transformer
...
Selection of Generator
...

• Maximum allowable step voltage dip
...

• Altitude and temperature
...

• Electrical characteristics – Number of phase, voltage, frequency
...

• Low inertia load, High inertia load

Based on above criteria selected generator is,

​

• Maximum demand

​

• Duty type

​= 240 kVA

​

​= Prime rated

• Loading factor of the engine

​= 0
...
8 kVA = 300 kVA
​= 400 / 230 V, 50 Hz

• Electrical characteristics

​

• Governor type

​= Electronic
​

• Method of excitation
• RMP

​

​

​

​= Permanent magnet
​= 1500

9
...

For the sizing and selection of cables three factors are considered
...
1
...


​Depend upon the method of installation and the presence of external
​influences
...
Cg
...
Cf

Cg – Correction factor for Grouping
Ca – Correction factor for Ambient Temperature
Ci – Correction factor for thermal insulation
Cf – Correction factor for protective Device

​

​

​Iz = It
...
2
...

Depend upon the impedance of the cable, the magnitude of the load current and the load
power factor
...
3
...

Short circuit temperature limit depend upon energy produced during the short circuit
condition
...

​

​Determine whether the conductors of the circuit protected thermally
...
t - Adiabatic Equation

​

​

​S = (Isc √ t )/ K

2 2

2

​t – Duration of Short Circuit

K – Factor Depending on the Cable type

​S – Conductor Cross sectional area
Isc – Short Circuit current (A) rms
The minimum size of the cable should satisfy the above three requirements
...
8 kVA

​Length of the cable from MDB to SDB-GF- 35 m
​System Voltage - 400 V
​Design ambient temperature - 30 C
0

​Cable installation method – Installed in air “ REFERENCE METHOD E” (Page-261)

​Type of cable – 4C XLPE/PVC-Cu
​ Determination of de-rating factors
th

i) Ca – Correction factor for ambient temperature is 1
...
73 ((In IEE 17 Edition Table 4C1, Page 268)
Specimen Calculation for the cable from MDB to SDB-GF

​ Ib = 55
...
54 A

​
Selected protective device current setting = In = 100 A
Calculated Current

​= In / (Ca x Cg)

Ic

​

​
​

​= 100 / (1
...
73)

​

​= 136
...
Ca
...
4 A
Iz < Ic and not satisfy the condition
If It = 192 A and cable 4C 50 mm sq, Iz = 192
...
Cg = 140
...
/1000) x Ib x L

Calculated voltage drop

​

​= (0
...
54 x 35

Table 4E2B, Page 287)

​

​

​= 2
...
t - Adiabatic Equation

​

​

​S > (Isc √ t )/ K

​

​

​

> 6x1000 x SQRT(0
...
38 mm sq

2 2

th

(In IEE 17 Edition

2

th

K- 115 (In IEE 17 Edition Table 4B1, Page 77)

​
Therefore selected cable is satisfied the short circuit rating of the cable

• Short circuit calculation is done from point to point of the installation
...


​

​

​

​If = U / / Z

​

​

​

​Z =

​

​

​

​

R=R1 + RS

X=X1+XS

​

U – Line to Line r
...
s voltage
R1 – Line resistance

If – Fault Current Line to Ground
Rs – Source resistance

​

X1 – Line impedance

Xs – Source impedance

​

R – Total up stream resistance

X – Total up stream impedance

• Calculation of SCL at source end When system is on transformer

​

​Transformer Data:
​

​Capacity: 250 kVA , Copper Loss: 3700 W, Usc = 5%
​

​Pc = sqr (I2)
...
009472
​

​Rs = 9
...
V / I = 0
...
032 Ohm = 32 m Ohm
​

​Xs = sqrt(sqr(Zs) – sqr(Rs)) = 30
...
05
= 5,000,000 VA
​

​

​

​

​

​

​

​

​Therefore short circuit current = Isc = Psc / sqrt (3) / V = 5000000/1
...
2 kA
• Calculation of SCL at source end when system is on Generator
​

​Generator Data:
​

​Capacity: 300 kVA , Generator Sub-Transient Reactance % (Xd): 15
...
1
​

​Xs = Xd
...
53 / 100) x 400 x 400 /(300 x 1000) = 0
...
82 m Ohm
​

​Rs = Xs x 0
...
28 m Ohm
​

​Zs = sqrt (sqr(Rs) + sqr(Xs) )
​

​
​

​Isc = V / sqrt(3)
...
32 / 83
...
77 kA

= sqrt (sqr(8
...
82) ) = 83
...
Field visit to lakvijaya caol power plant
10
...
Introduction
The Lakvijaya Power Station is the largest power station in Sri Lanka
...
The first 300megawatt phase was completed and ceremonially commissioned on 22 March 2011
...
7 TWh of electricity annually — a significant amount when compared to Sri Lanka's
[4]
total production of 11
...
The plant is connected to the grid via 115 km (71 mi)
220-kilovolt transmission line to Veyangoda
...


10
...
Operation
In the plant, basically the electricity is produced using a steam turbine which is capable of
producing 300MW
...
Coal is imported from Indonesia since it is cheap and
good quality
...
Despite this, the vessels that carry coal come
[11]
from a Russian port
...
The ships are
anchored around 4 km from shore
...

The coal should be maintained around 10% moisture content immediately before it is used
...
There are five "mills" that pulverize (grind)
the coal
...


There are 3 fan system
• forced draft(use to supply coal to proper place)
• induce draft(stop fire going out form the path)
• primary draft
There are mainly two outputs
• Bottom ash
• Fly ash
bottom fly ash used for cement industry
...
3 Fly ash discharging system
Another type of ash discharging system normally ash has + & - molecules and when we
supply 72kv to both sides of plates ash got attach both sides of surface
...
4
...
Each pump pumping easily pumps can block by
seashell and other animals, so s a recommendation they inject NACL inside pumps for better
use and removing them
...
There were another water
cleaning system know n’s as gravity filters
...
Such things may be molecules, ions
or other small particles
...
3mc
...

Also by eclectic conductivity we can check the mineral ingredient
...


​

​

​

Figure 7steam process

Steam pressure is 150 bar
1kg coal 6400kcl energy

10
...
Flue Gas desulfurization process (separate sulfur from flue gas)
This process separate sulfur because it cause to acid rain and temperature increment in
surrounding area's ingredient in flue gas with the close connection of sea water S seperate
and joints with sea water
...
It's
known as Aeration process
...
5
...

Now we can't see any smoke on top of the
furnace
...


10
...
Turbine
When supply steam is stopped the middle long axel can lab because of high & weight of axel
...
As a generator must rotate at constant synchronous speed according to the frequency of
electric power system the most common speed is 3000RPM for 50hzand 3600RPM for 60hz

10
...
Generator
As a cooling method hydrogen used to cool generator, between rotor & stator air gap
including hydrogen for it
...


10
...
Transformer
There are 3 transformers each one 360kva capacitor
...
There also SSP called transformers used to supply inside load
...

There also wind turbine system which supply 65MW-30MW consumption to CEB
...
9
...
6 billion cubic meter of air in
hour is delivered by air fans into the furnace
...
The steam pressure is 200bar
...
ACPL-782T Automotive Isolation Amplifier, s
...
: Avago Technologies
...
, 2004
...
l
...

Remy International, I
...
Remy HVH250 Application Manual, Pendleton: Remy
International, Inc
...
A
...
A
...
d
...
[Online]
Available at: http://infosys
...
com/espanol
...
/content/1034/el320x/html/bt_rtd_technology
...


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