WOLKITE UNIVERSITY COLLEGEE OF ENGINEERING AND

TECHNOLOGY
DEPARTMENT OF ELECTRICAL AND COMPUTER ENGINEERING
Control Stream
Industry Internship Report Hosting Company Amhara Metal Industry and
Machine Technology Development

By:

No. Name ID No
1. Mekides Mihiret ENGR 069/10
2. Yared Wendale ENGR 939/10

Advisor: Mr. Girma .

February, 2022
Bahir Dar, Ethiopia
 Declaration

We are 5th year Electrical and computer Engineering student in Wolkite University, and We
have been undertaken our internship experience in Amhara metal industry and machine
technology development enterprise (AMIMTDE) for a period of three months from December
2021- February 2022 under the guidance of Mr. Girma, academic advisor and Mr. Adissu Mulat
company advisor.

Student name: ID No Date Signature

Mekides Mihiret ENGR062/10 ________ ________
Yared Wendale ENGR939/10 ________ ________

Academic advisor: Date: Signature

Mr. Girma . _____________ __________

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 Acknowledgment

First of all, we would like to thank the almighty God for his unforgettable help in all direction.

We express our thankfulness to God for his blessing and guidance throughout our entire training.

We would like to express our profound to Amhara metal industry and machine technology
development enterprise which is willing to accept our internship program, for valuable guidance
and providing necessary facilities and source during this internship program.

We would like to thanks for Wolkite University for providing such kind of an opportunity for
students to apply their understanding in practical knowledge and improve theoretical knowledge.

Next to this we give great altitude for our advisor for Mr. Girma for academic advisor and Mr.
Addisu Mulat for company advisor.

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Contents
Declaration.......................................................................................................................................................................i
Acknowledgment............................................................................................................................................................ii
List of Figures..................................................................................................................................................................6
List of Aacronyms...........................................................................................................................................................7
Abstract........................................................................................................................................8

CHAPTER ONE..........................................................................................................................1

1. BACKGROUND OF THE COMPANY.................................................................................1

1.1 Introduction........................................................................................................................1

1.2 Mission of the company.....................................................................................................3

1.3 Vision of the company.......................................................................................................3

1.4 Objectives of the enterprise...............................................................................................3

1.5 Values of the company.......................................................................................................3

1.6 Organizational structure of the company...........................................................................4

1.7 Work flow.....................................................................................................................5

1.8 Key Stake holder of AMIMTDE.......................................................................................5

1.9 Product of the company.....................................................................................................6

2. Overall Internship Experience.................................................................................................6

2.1 Objectives of the internship...............................................................................................6

2.4 Overall System Components and Operations....................................................................7

Selection modes AUTO (Automatic mode).................................................................................9

Manual mode...............................................................................................................................9

Test mode.....................................................................................................................................9

2.4.2 Air conditioning system..................................................................................................9

2.4.3 Distribution power transformer.....................................................................................10

Conservator................................................................................................................................12

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 Breather (silica gel)....................................................................................................................12

Oil level indicator......................................................................................................................13

Radiator......................................................................................................................................13

Drain valve.................................................................................................................................13

Bushing......................................................................................................................................13

Tape changer of transformer......................................................................................................13

Coils/winding.............................................................................................................................14

Magnetic core.............................................................................................................................15

Tank...........................................................................................................................................17

Working principle of the transformer........................................................................................17

Transformer cooling systems.....................................................................................................17

2.4.4 Engine generator...........................................................................................................18

1. Engine....................................................................................................................................19

2. Alternator...............................................................................................................................19

3. Fuel System............................................................................................................................19

4. Cooling and Exhaust Systems Cooling System.....................................................................20

5. Exhaust System...............................................................................................................21

6. Lubrication System........................................................................................................21

7. Battery Charger..............................................................................................................21

8. Control Panel...................................................................................................................21

Operating modes MAN Mode...................................................................................................22

START button............................................................................................................................23

STOP button /RESET button.....................................................................................................23

AUTO Mode..............................................................................................................................23

TEST Mode................................................................................................................................23

9. Automatic Voltage Regulator........................................................................................23

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 2.5 Transformer Maintenance and Testing Workshop..........................................................24

2.6 Major duties of the Intern................................................................................................28

2.7 Challenges faced and measures.......................................................................................28

3. Benefits Gained from the Internship......................................................................................30

3.1 Upgrading theoretical knowledge and Improving Practical skills...................................30

3.2 Improving team playing skills.........................................................................................30

3.3 Improving interpersonal communication skills...............................................................31

3.4 Leadership skills..............................................................................................................32

3.5 Over All Achievements of the Intern...............................................................................33

CHAPTER FOUR 4. CONCULSION AND RECOMMENDATIONS...................................33

4.1 CONCULSION................................................................................................................33

4.2 RECOMMENDATIONS.................................................................................................34

REFERENCE.............................................................................................................................37

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 List of Figures

Figure 1 Organizational structure of the company ......................................................................... 4

Figure 2 Work flow of company ..................................................................................................... 5
Figure 3 Automatic transfers switching .......................................................................................... 8
Figure 4 ATS control panel............................................................................................................. 9
Figure 5. Different parts of the transformer .................................................................................. 11
Figure 6. Internal Parts of MV Transformer ................................................................................. 12
Figure 7.Tape changer of transformer .......................................................................................... 14
Figure 8. Transformer magnetic coils ........................................................................................... 14
Figure 9. Transformer magnetic core............................................................................................ 15
Figure 10. Transformer type in shape ........................................................................................... 16
Figure 11. front side view internal part ......................................................................................... 16
Figure 12. Generator controller ..................................................................................................... 22
Figure 13. DC Winding resistance test ......................................................................................... 23
Figure 14. Tern ratio tester............................................................................................................ 24
Figure 15. Horizontal winding machine ....................................................................................... 24
Figure 16. vacuum drying oven .................................................................................................... 25
Figure 17. Transformer insulation tester ....................................................................................... 26
Figure 18. Oil treatment machine ................................................................................................. 26
 List of Aacronyms

AC Alternative Current
AMIMTDE Amhara Metal Industry and Machine Technology
Development Enterprise
AVR Automatic voltage regulator,
ATS Automatic transfer Switch
DC Direct Current
EMF Electro Motive Force
HV High Voltage
LED Light Emitting Diode
LV Low Voltage
NWR North West Region
UIL University Industrial Linkage
 Abstract

This paper is a report of an internship program at Amhara Metal Industry and Machine
Technology Development Enterprise (AMIMTDE). It is prepared as one of the compulsory
inputs for the proper execution of the internship program.
This report is considered as the way for intern students to prepare or ready ourselves for real
practical world both in technical and social perspectives and also it describes selection of a
problem that is facing during internship and solves such problems.
 CHAPTER ONE
1. BACKGROUND OF THE COMPANY
1.1 Introduction
Manufacturing industry in Ethiopia has been started in 1920s with a simple processing
technology that produces agriculture-based products. However, the manufacturing sector is still
infant, dominantly semi-processing, and performs at a minimal capacity. The manufacturing
sector has persistently faced high production cost, severely constrained supply and poor quality
raw materials and technology, both mainly imported, witnessing little improvements in the main
areas of challenges over the years. It has neither transformed itself to high tech processing nor is
competitive in the international market.

1.1.1 Background of the company

The fixed assets are located in Amhara Region at two places, namely at Bahir Dar and
Kombolcha City. The assets found at Bahir Dar and Kombolcha production center consist of
production office buildings, machinery, motor, office furniture and equipment. Both centers are
coordinated by main office named as Amhara metal Industry and machine development
enterprise. The Kombolcha production center is located about 450 kilometers from the center of
Bahir Dar. Whereas, the other one and the main office is sited at the center of Bahir Dar city.
The center is established in 1985 E.C. by the name of Bahir Dar Rural Technology Promotion
Center with the aim of multiplying and popularizing agricultural implements around mandate
area. It was organized in Small-scale agricultural implements, rural industry development and
rural energy development team.
After 1996 E.C, the center has been re-organized with the objective of supporting the
sustainability of the agricultural development in the Region through design, testing and
promoting agricultural implements. This time it was rearranged in prototype design & studies
and production & maintenance team.
In 1999, the name of the center is changed to Bahir Dar Agriculture mechanization and Food
Science research center and started to conduct research on generating/selecting, developing,
adopting and promoting appropriate agricultural mechanization technologies at the regional
level. Bahir Dar Agricultural Mechanization & Food Science Research Center, (BAM&FSRC)
undertook problem oriented agro-ecology based research on pre-harvest and irrigation
technologies, post-harvest handling and processing technologies, animal husbandry technologies

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And alternative energy technologies for developments, testing and popularization of need based
farm implement and machinery to increase productivity of land and labor through timelines of
operations efficient use of inputs, improvement in quality of produce and safety and comfort of
farmers, and reduce drudgery. The major activities encompass; Conducting and/or promoting
research and develop in appropriate mechanization, processing and alternative energy
technologies to increase agricultural production and productivity of the region, collecting
processing and disseminating information in appropriate technologies and food utilization to the

needs of the farmers.

The sector's contribution for the national GDP is stagnated at less than 5% for the last 20 years.
Existing technology transfer mechanisms are poorly institutionalized. As a result, about 80% of
the national exports are agricultural, while manufacturing accounts about 10%, which in terms of
value is only about 0.5% of the total export.
For this reason, it has been found necessary for the Amhara National Regional State to create a
capacity and develop inspiration in the metal and machine technology development. The Amhara
Metal Industry & Machine Technology Development Enterprise is a governmental institution
which was transformed by regulation No. 127/2014 under the provision of article 58, sub article
7 of the revised national constitution of the Amhara national regional state. This enables to
achieve the development goals of the industrial sector in the region. With the view to support the
development, it has been found necessary to accelerate the industrialization transformation of the
region by getting rid of investment limitations, inadequacy of productivity, least technological
capability, poor supply of production inputs, weak commercialization confronted on the major
manufacturing industry components and thereby filling the gap of the market therein.
In addition to this the enterprise is making a great research and analysis on socio economic on
solar system like solar street light, solar operated pump and other others. Finally, in 2008 E.C.
the name of the center is changed in to Amhara Metal Industry and Machine Technology
Enterprise (AMIMTDE) and started to conduct research on generating/selecting, developing,
adopting and promoting appropriate machine technologies at the regional level.
(From unpublished documents of the company).
For this report the data is conducted in AMIMITDE at Bahir Dar branch.

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1.2 Mission of the company
The vision of the AMIMTDE is to become one of the ten premier best technology institutions in
the Africans in 2017 E.C.

1.3 Vision of the company

The vision of AMIMTDE is to contribute for production of quality machine that are used for
both the technology and agriculture and becoming competitive in the world.

1.4 Objectives of the enterprise

The General objective of the enterprise is to full fill the gaps of Agricultural technologies
encountered the small folder farmers for increasing production and productivity of the
Agricultural products.

1.5 Values of the company

• We are passionate about our customer
• Our employees are the heart of our business
• We are committed to deliver exceptional values
• Profitability is the core of our business
• We believe in working together as team and as partner
• We never stop learning and growing  We care about the environment.

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1.6 Organizational structure of the company

General Manager Secretary

Auditor
Fabrication/subsidiary
Association manager
Law service

Vice general manager Vice general manager

Secretary
Secretary

Technology Production & Quality Sales, finance & Resource

development & market transferring control & Administration Supporting
Market planning Process manager Measurement Process manager
Process manager Process
Manager Human power development
& administration supporting
process manager
Socio -economic Metals industry &
research sub machine work sub
process coordinator process Plan following &
coordinator information
Agriculture & Foundry & woods Technology supporting
technology design work sub process Process manager
sub process coordinator
coordinator
Electrical and
electronics sub
Industry &
process
technology design
coordinator
sub process
manager Assembly and
finishing work sub
process
Market planning coordinator
sub process
coordinator

Figure 1 Organizational structure of the company

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1.7 Work flow

5
 Figure 2 Work flow of company
1.8 Key Stake holder of AMIMTDE

The main stakeholder of AMIMTDE is the Amhara Regional government, which is the owner of
the corporation, the employees and customers. The owner of the AMIMTDE is the Amhara
Regional government itself. AMIMTDE is the big company that control and monitor the region
Agricultural technology production and supply, Food processing equipment production and
supply and Construction equipment production and supply as a whole. The major customers of
AMIMTDE are householders, different companies and schools. In addition, governmental and
non-governmental organizations, industries, small scale enterprises and business institutes are
customers and beneficiaries of AMIMTDE. The corporation in general provides service to the
public.

1.9 Product of the company

Development Enterprise was established to meet the gap of technology requirement among
Manufacturing Industry, Agriculture Sector, Micro and Small enterprise in terms of product and
service. Currently the company produce different product based on reverse engineering
techniques. Such techniques are important for developing country to produce different spare part
and machine components. The current main product of the company is:

➢ Car parking and shade

➢ Fish feed pelletizer machine

➢ Pipe bender

➢ Manual bar cuter

➢ Seed cleaner

➢ Hand puller winch with self-locking without wire rope

➢ Screw type lift table truck without hydraulic pump

➢ Thresher machine.

CHAPTER TWO

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 2. Overall Internship Experience
2.1 Objectives of the internship
2.1.1. General objective
To upgrade the theoretical knowledge and to relate our theoretical knowledge with the practical
skills.

2.1.2. Specific objectives

 Internship students will develop skills and techniques directly applicable to their
careers.
 Internships will provide students the opportunity to develop attitudes conducive to
effective interpersonal relationships
 Internships will provide students with an in-depth knowledge of the formal functional
activities of a participating organization.
 Internship programs will enhance advancement possibilities of graduates.
In general, an Internship program is thought of as a program which "bridges the gap" between the
academic environment and a future work environment. Many employers prefer students who
have previous work experience and the Internship provides that. Students that participate in an
Internship are generally more confident and more qualified when seeking future employment

2.2. How did we get the company?

In the first day we get the Manager of the company and then he takes the letter that we take from
our industrial leakage. In the second day the manager has given us an adviser Mr. Addisu who
control and guide us. He gives us orientation or description on:

• Work Ethics

• What we should have to do and working and working time

• Introduce with the shop mate (shop mates)

• The working rooms (Those are maintenance room, drying room and testing room).

• Introduce the Engineering methods, tools and techniques

• Safety issue we should have to take while doing

Machines (winding, oil treatment , welding, drying and integrated test machine).
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2.4 Overall System Components and Operations

As we indicated in the above we devote most of our time in power and maintenance sections.
Work that we done in this section starts from Automatic transfer switching (ATS), Air
conditioning system, distribution transformers, and generators.

2.4.1 Automatic transfer switching (ATS)

As the society develops, people required better power supply such as two power sources even
three power sources to keep continuous power supply. This will need a device to transfer
between two power sources and three power sources.

Figure 3 Automatic transfers switching

Two power sources transferring

ATS comprises of transfer switch, board and circuit, and enclose. It automatic can carry out
transfer to keep one input power supply: While Mains available, it‟s on the Mains end for power
supply; While Mains fail or under desired value the sensors sends signals to start the generator
Then, it will transfer to generator end for power supply. While Mains recover, it will return to
Mains end for power supply. Mains and generator will not supply power at the same time.

Control panel detect mains voltage, generator voltage, the voltage on the emergence of unusual
conditions. The realization of the generating units can automatically start and shutdown.
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The controller has communication port which match with the communication interface module.
The relative software can display the whole parameters measured and state information; it also can
set various parameters. It enables to obtain more information which can‟t get from panel.

Figure 4 ATS control

panel

Selection modes
AUTO
(Automatic mode)

When Main power is

available the controller
detects and main
power will take the load. But, when main power became abnormal (any voltage below or above
setting) the controller or the board detects and send signal to start up generator. As result,
Generator starts up and sets up normal voltage. After the delay, switch will transfer to generator
end for power supply and then generator takes the load. When Mains recovers: after the delay,
switch will transfer to Mains end for power supply main power takes the load.

Manual mode

Manual operation is used in case of switches and control system failure to insure power supply.
You can choose the close direction through “SW1” and “SW2” if the voltage for Mains and
Generator resource are normal.
Test mode

Switch only sends generator startup signal without actual transferring, and Mains is still
supplying power to load. In this situation, generators can startup without taking load. When put
switch back to “AUTO”, generator will stop immediately.

2.4.2 Air conditioning system

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There is enormous amount of heat due to working different electrical equipment and environment
conditions. Therefore appropriate air conditioning system is essential for proper functioning of
all the system of Network Elements. For all air conditioning systems the principle remains the
same where by the heat is removed from one area and replaced with chilled dry air and the hot
air is expelled, normally to the outside atmosphere, and sometimes the reverse. Every air
conditioner has a compressor inside it. It works to compress and pump the refrigerant gas.
Compression of refrigerant produces heat. To dissipate this heat, compressed refrigerant is
pumped to the condenser coils where a fan blows the heat out to outer atmosphere. During the
process, refrigerant takes the liquid form. This liquid refrigerant is pumped towards expansion
valve. Expansion valve releases the appropriate amount of refrigerant to evaporator (cooling
coils) where liquefied refrigerant takes gaseous form. Conversion from liquid to gaseous state
due to expansion produces chillness because energy is absorbed from the surrounding. Air when
passes through fins that is, attached to coils, gets cooled and blown to the room.
Refrigerants are substances used by air conditioners to transfer heat and create a cooling effect.
Air-conditioning systems use specially formulated refrigerants designed to change state at
specific temperatures providing optimum cooling. Portables use a refrigerant called R-22 or
HCFC-22. HCFC stands for hydro chlorofluorocarbon.

This is currently the most common refrigerant used by air-conditioning systems.

2.4.3 Distribution power transformer

A distribution transformer is a transformer that provides the final voltage transformation in the
electric power distribution system, stepping down the voltage used in the distribution lines to the
level used by the customer. Transformer can operate 24 hours/day, 365 days/year and have very
long lifetimes. Energy consumption during its service life is the dominant factor in their lifecycle
assessment. Practical efficient transformer made AC power distribution feasible by using
distribution transformers. No matter what the shape or size, a transformers purpose remains the
same: transforming electrical power from one value to another.
Step down Transformer that installed in sites of North West Region Amhara National Regional
State Metal Industry and Machine Technology Development Enterprise reduce from 15000 KV
or 33000 KV power lines (EEU) to 380V. There is an inlet and outlet hole (opening) in the
powerhouse for the lines to come in and out respectively. There is Conductor buried under
ground for earthling purpose. An HV terminal comes in while LV terminal gets out

10
Figure 5. Different parts of the transformer

11
 Figure 6. Internal Parts of MV Transformer

Some parts of a transformer are the following:

Conservator

It is a big cylindrical tube located on the upper position of a transformer and connected to the
main thank, which is completely filled with oil, through pipe. It is partially filled with oil. When
the temperature of the transformer increases, the oil inside it expands to conservator and vice
versa. It allows a room for oil expansion and contraction.

Breather (silica gel)

They are small cylindrical device placed in the vent pipes of conservators. It dries the air entering
the conservator as volume of oil contracts on the transformer cooling. It uses the moisture
absorbing properties of silica gel crystals. These crystals need replacement when it becomes
saturated with moisture. Replacement is indicated by a change in color of the crystals from blue
to pink. These breathers also have an oil cup fitted with, so that the dust particles get settled in
the cup.

Oil level indicator

It is used to show the oil level in the transformer. This is an ordinary part situated on the side of
the conservator for proper oil checking oil Tank wants a specific amount of oil.
Radiator

Basically used for the cooling by the Means of natural air. These are used for cooling of the
transformer oil. Radiators are used in a transformer to cool the transformer oil through natural air
or forced air flowing in these Radiator fins.

Drain valve

This valve is used for taking damaged Oil from the oil tank for the proper oil collection this
Valve is situated under the oil tank.

Bushing

Bushing is an insulating device which covers the conducting material. A typical bushing design
has a 'conductor', (usually of copper or aluminum and of other conductive materials), surrounded
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by insulation, except for the terminal ends. This design has to ensure that the electrical strength
of the insulated material is able to withstand the penetrating 'electrical energy' passing through
the conductor, via any highly stressed areas. A fixing device will also be attached to the
insulation to hold it in its location.

Tape changer of transformer

It is a small number of additional turns fitted on the primary winding, such that by switching the
incoming supply to one of the additional set of turns, a change in the voltage ratio is achieved in
proportional to the additional turns. It is used for regulation of the output voltage to required
levels.

This is normally achieved by changing the ratios of the transformers on the system by altering the
number of turns in the primary winding of the transformer. The voltage regulator helps to
maintain balance between the power output and the required output level. The principle of
automatic voltage regulation involves the process of maintaining the voltage flow at a specified
level at all times.

There are voltage power surges that may be caused by unanticipated conditions, such as lightning
or power failures and unless the electrical equipment has an automatic voltage regulator, the
power surges to the equipment could easily damage that equipment when power is turned off and
on.

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 Figure 7.Tape changer of transformer

Coils/winding

Where incoming alternate current (through primary winding) generates magnetic flux, which in
turn develop a magnetic field feeding back a secondary winding.

Figure 8. Transformer magnetic coils

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Magnetic core

Allowing transfer of magnetic field generated by primary winding to secondary winding by

principle of magnetic induction and used to provide a controlled path for the magnetic flux
generated in the transformer. The core is generally not a solid bar of steel, rather a construction
of many thin laminated steel sheets or layers. This construction is used to help eliminate and
reduce heating.

Figure 9. Transformer magnetic core

Transformers generally have two types depending on the type of core it uses: Core Type and
Shell Type. These types are distinguished from each other by the manner in which the primary
and secondary coils are place around the steel core.

 Core type- the windings surround the laminated core.

Shell type-the windings are surrounded by the laminated core.

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Figure
10.

Transformer type in shape

Figure 11. front side view internal part

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Tank

Serving as a mechanical package to protect inside parts, as a holding vessel for transformer oil
used for cooling and insulation and bushing (plus auxiliary equipment where applicable).

Working principle of the transformer

A power transformer is a static electrical device that transfers energy by inductive coupling
between its winding circuits. A varying current in the primary winding creates a varying
magnetic flux in the transformer's core and thus a varying magnetic flux through the secondary
winding. This varying magnetic flux induces a varying electromotive force (EMF) or voltage in
the secondary winding.
It is important to remember that transformers do not generate electrical power; they transfer
electrical power from one AC circuit to another using magnetic coupling without changing the
frequency. The ratio between the numbers of actual turns of wire in each coil is the key in
determining the type of transformer and what the output voltage will be. The ratio between
output voltage and input voltage is the same as the ratio of the number of turns between the two
windings. A transformers output voltage is greater than the input voltage if the secondary
winding has more turns of wire than the primary winding. The output voltage is stepped up, and
considered to be a "step-up transformer". If the secondary winding has fewer turns than the
primary winding, the output voltage is lower. This is a "step-down transformer". The relationship
between the input voltage and output voltage, and the input current and the output current are
given by two simple equations.

Transformer cooling systems

It is essential to control the temperature within permissible limit to ensure the long life of
transformer by reducing thermal degradation of its insulation system. The transformer oil is
stable at high temperature and has excellent electrical insulating properties. The oil helps cool the
transformer. Because it also provides part of electrical insulation between internal live parts,

17
Transformer oil must remain stable at high temperatures for an extended period. To improve
cooling of these distribution transformers, the oil-filled tank may have external radiators through
which the oil circulates by natural convection.

Liquid-filled transformers, most often used by electric utilities, have several efficiency
performance advantages over dry-type transformers. Liquid-filled transformers tend to be more
efficient, to have greater overload capability and to have a longer service life (due to a greater
ability to reduce hot-spot coil temperatures and higher dielectric withstand ratings). Function of
transformer oil:
It serves as liquid insulating media.
•
It uses to cool the transformer down.
•
It helps to preserve the core and winding as they are fully immersed.
•
It prevents direct contact of atmospheric oxygen with cellulose made paper
insulation of windings, which is susceptible to oxidation.

2.4.4 Engine generator

Generator is a device that produces electricity from mechanical energy. The mechanical energy
in turn is converted from chemical or nuclear energy in various types of fuel, or obtained from
renewable sources, such as wind or falling water. Turbines and internal combustion engine are
common systems that supply the mechanical energy for such devices. Generators are made in
wide range of sizes, from very small machine with a few watts output to very large power plant
devices providing Giga watts of power.

Amhara National Regional State Metal Industry and Machine Technology Development
Enterprise uses flexible and reliable generator. It is possible to make a set up so it can be operates
manually or automatically. The Basic Principe:

Electricity is produced in alternators by electromagnetic induction. To generate electricity in a

coil either the coil should rotate with respect to a magnetic field or a magnetic field should rotate
with respect to the coil. It is capable to generate AC power at a specified frequency.
When magnetic field lines cut across a conductor, a current is induced in the conductor. In general,
an alternator has a stationary part (stator) and a rotating part (rotor). The stator contains windings
of conductors and the rotor contains a moving magnetic field. The field cuts across the conductors,

18
generating an electrical current, as the mechanical input causes the rotor to turn. This produces the
alternating current (AC) output of the generator.

The value of the voltage generated depends on-

•
The number of turns in the coil.
•
Strength of the field.
•
The speed at which the coil or magnetic field rotates

1. Engine

The engine is the source of the input mechanical energy to the generator. The size of the engine
is directly proportional to the maximum power output the generator can supply. There are several
factors that you need to keep in mind while assessing the engine of your generator.

2. Alternator

The alternator, also known as the „gen head‟, is the part of the generator that produces the
electrical output from the mechanical input supplied by the engine. It contains an assembly of
stationary and moving parts encased in housing. The components work together to cause relative
movement between the magnetic and electric fields, which in turn generates electricity.

3. Fuel System

The fuel tank usually has sufficient capacity to keep the generator operational for 6 to 8 hours on
an average. In the case of small generator units, the fuel tank is a part of the generator‟s skid base
or is mounted on top of the generator frame. For commercial applications, it may be necessary to
erect and install an external fuel tank.

Generator engines operate on a variety of fuels such as diesel, gasoline, propane (in liquefied or
gaseous form), or natural gas. Smaller engines usually operate on gasoline while larger engines
run on diesel, liquid propane, propane gas, or natural gas. Certain engines can also operate on a

19
dual feed of both diesel and gas in a bi-fuel operation mode. In our case the engine that installed
in AMIMTDE consumes diesel fuels.

Common features of the fuel system include the following:


Pipe connection from fuel tank to engine – The supply line directs fuel from the tank to
the engine and the return line directs fuel from the engine to the tank.

Ventilation pipe for fuel tank – The fuel tank has a ventilation pipe to prevent the buildup
of pressure or vacuum during refilling and drainage of the tank. When you refill the fuel
tank, ensure metal to metal contact between the filler nozzle and the fuel tank to 
 avoid sparks.

 Overflow connection from fuel tank to the drain pipe during refilling of the tank does not
cause spillage of the liquid on the generator set.– This is required so that any overfl ow
 
 Fuel pump – This transfers fuel from the main storage tank to the day tank.

Fuel Water Separator / Fuel Filter – This separates water and foreign matter from the
liquid fuel to protect other components of the generator from corrosion and contamination.

Fuel Injector – This atomizes the liquid fuel and sprays the required amount of fuel into
the combustion chamber of the engine.

4. Cooling and Exhaust Systems Cooling System

Continuous usage of the generator causes its various components to get heated up. It is essential
to have a cooling and ventilation system to withdraw heat produced in the process.

Here in our case in AMIMTDE Raw/fresh water is used as a coolant for generators. A standard
radiator and fan is mounted on the generator and works as the primary cooling system. It is essential
to check the coolant levels of the generator on a daily basis. pump should be checked and the heat
exchanger should be cleaned. The generator should be placed in an open and ventilated area that
has adequate supply of fresh air.

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5. Exhaust System

Exhaust fumes emitted by a generator are just like exhaust from any other diesel or gasoline engine
and contain highly toxic chemicals that need to be properly managed. Hence, it is essential to install
an adequate exhaust system to dispose of the exhaust gases. Exhaust pipes are usually made of cast
iron, wrought iron, or steel. These need to be freestanding and should not be supported by the engine
of the generator. Exhaust pipes are usually attached to the engine using flexible connectors to
minimize vibrations and prevent damage to the generator‟s exhaust system.

The exhaust pipe terminates outdoors and leads away from doors, windows and other openings to
the house or building.

6. Lubrication System

Since the generator comprises moving parts in its engine; it requires lubrication to ensure
durability and smooth operations for a long period of time. The generator‟s engine is lubricated
by oil stored in a pump. You should check the level of lubricating oil every 8 hours of generator
operation. You should also check for any leakages of lubricant and change the lubricating oil
every 500 hours of generator operation.

7. Battery Charger

Starting motor is the basic component of engine generator this motor uses Battery for starting. The
start function of a generator is battery-operated. The battery charger keeps the generator battery
charged by supplying it with a precise voltage. The battery can be charged by using AC source from
generator or EEU. But the battery should not be detached from its place because the control panel of
the generator uses its power from the battery. The DC output voltage of the battery charger is set at
2.33 Volts per cell, which is the precise float voltage for lead acid batteries.

8. Control Panel

This is the user interface of the generator and contains provisions for electrical outlets and controls.
Different manufacturers have various features to offer in the control panels of their units


Electric start and shut-down – Auto start control panels automatically start your
generator during a commercial power outage, monitor the generator while in operation,
and automatically shut down the unit when no longer required.
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 
Engine gauges – Different gauges indicate important parameters such as oil pressure,
temperature of coolant, battery voltage, engine rotation speed, and duration of
operation.


Generator gauges – The control panel also has meters for the measurement of output
current and voltage, and operating frequency.

NWR AMIMTDE installed Generator intelligent controller. It is based on high performance

computer chip, can modify the control procedure and protection parameters of generator, which
incorporated kinds of functions, such as measuring, controlling, protection, and programmable
management. The controller measure and display all output electric parameters of the generator,
and rpm, oil pressure, coolant temperature, DC source voltage and running hours of the engine,
and the voltage and current to make sure data accuracy. The controller has a communication port,
this port need to match use with communication interface module. Realizing long distance
monitor, or communication with PC, fully realizing functions of remote signaling, telemeter and
remote control, can read and set the running parameters of controller. LED indicators are used
for indicating the operation mode of controller and the running status of Generator, and LCD
displays each measuring parameter and status.

Figure 12.

Generator controller
Operating modes MAN Mode

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The engine can only be started and stopped manually using the START and STOP keys, as is the
case for switching the load from the mains to the generator by pressing the MAINS/GEN keys
and vice versa. When controller is running in MAN mode, LED above the button lights up.

The controller controls generator start and stop by pressing “START” and “STOP” buttons.

START button

The button is used for “MAN” mode, to start Generator. When controller is setting in

MAN operation mode, pressing this button can start the Generator. During the period from
controller performs start procedure to Generator is normal running, the normal running LED
above the button flash, and LED keep on when the Generator is running normally.

STOP button /RESET button

The button is used for manual stop generator, when controller is set in “MAN” mode, this button
can stop the Generator. When controller performs stop procedure, LED above the button on,
when fail to stop, LED flash.

AUTO Mode

The engine is started automatically in the case of a mains outage (outside the set limits) and stops
when the mains parameters are once again within said limits, on the basis of the times set in
menu of Mains control. In the presence of voltage, the load is switched automatically in both
directions. When controller is running in AUTO mode, LED above the button lights up.

TEST Mode

The engine is started immediately even in the absence of the conditions normally required for the
automatic mode. There is normally no load switching. When controller is running in test mode,
LED above the button lights up.

9. Automatic Voltage Regulator

An automatic voltage regulator, AVR for short, is a device that is designed to automatically
control, adjust or maintain a constant voltage level.
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In addition to regulating the generator voltage, the AVR circuitry includes under-speed and
sensing loss protection features. Excitation power is derived directly from the generator
terminals. Positive voltage build up from residual levels is ensured by the use of efficient
semiconductors in the power circuitry of the AVR.

2.5 Transformer Maintenance and Testing Workshop

There are different machines found in the transformer maintenance and testing work shop
These machines perform different tasks. Some of the machines are shown below;

2.5.1 DC Resistance test

Transformer winding resistance tests are obtained by passing a known DC current through the
winding under test and measured the resistance across each phase. In this condition the DC
resistance of each phase must be equal or the ratio between highest DC resistance to lowest DC
resistance must be less than or equal to 1.02. Apply these conditions for all tap position.

t
Figure 13. DC Winding resistance tes
2.5.2 Transformer turn ratio test

Transformer turn ratio test is an essential test. By using transformer turn ratio tester device
connect the positive terminal of device to HV side and the negative terminal of device to the LV
side of the transformer and fill the parameter in to the device. After finished connection and
arrangement press the test button and read results.

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In the result we observed that, the theoretical and measured values are much similar and the error
was between -0.4% and +0.4%.

Figure 14. Tern ratio tester

2.5.3 Transformer Winding Machine

Winding machine is mainly used for wind the primary and secondary coil and also used to
unravel the damaged coil of the transformer.

Figure 15. Horizontal winding machine

2.5.4 Vacuum Drying machine
This machine is used to dry ( under vacuum state) transformer and transformer coil. The preasure
changed vacuum drying process of this machine has fully considered the evaporating principle
and heating process during drying period, which prevent moisture in the deep inside of insulation
can notbe evaporated out due to the temperature increase too quickly during drying period The
temperature of deep inside will be equal to the temperature of surface to that all moisture can be
evaporated out properly. In this way the drying time can be decreased significantly, so this

25
machine is most suitable to dry (under vacuum state) transformerperienceAnd advanced
technology.

Figure 16. vacuum drying oven

2.5.6 Insulation Resistance/Megger Test of Transformer

Insulation resistance test is done after drying the active part of maintained transformer and also
after immersed to treated oil.
Insulation resistance test of transformer is essential type test. This test is carried out to ensure the
healthiness of overall insulation system of an electrical power transformer. The insulation
resistance (IR) is a spot insulation test which uses an applied DC voltage . The measured
resistance is intended to indicate the condition of the insulation or dielectric between two
conductive parts, where the higher the resistance, the better the condition of the insulation.
Procedure of Insulation Resistance Test of Transformer:
 Firstly the positive terminal of the megger is connected to primary side and negative
terminal to ground.

 Then readings are recorded after application of voltage

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 Figure 17. Transformer insulation tester

2.5.7 Oil treatment machine

This machine is used to treat the impurity of transformer oil to increase the breakdown voltage of
oil by filtering solid part and evaporating the liquid part of the impurity.

Figure 18. Oil treatment machine

2.5.8 Transformer testing machine

The transformer testing machine is to measure any three phase transformer faults. The
testing machine is tests no load test (open circuit test), on load test (short circuit test),
Induced over voltage test (dv d f test), Magnetic balance test and vector group test.
NO load test (open circuit test): is a transformer is performed to determine no load loss
(core loss). No load tests are tests that apply rated voltage in the primary side at the no
load state of the secondary side.
ON load test (short circuit test): is the load and excitation is applied to the high voltage
or to the low voltage winding depending up on the rating.

27
 Induced over voltage: test is also called double voltage double frequency test .This test
carried out at a test a frequency which is twice the rated frequency at which the
equipment is supposed to the operate during its life time.
Magnetic balance test: is to verify the imbalance in the magnetic circuit also to identify
its turn faults in the transformer at the early stage of manufacturing work.
Vector group test: is the international electro technical commission (IEC) method of
categorizing the high voltage (HV) winding and low voltage (LV) winding configurations
of three phase transformer.
Example wye (Y) HV and delta LV winding with a 30 degree leads denoted by DYN5,
DYN11…

Figure 19. Transformer Test bench

2.6 Major duties of the Intern

As the major duties of Amhara National Regional State Metal Industry and Machine Technology
Development Enterprise is monitoring, operating and maintaining of power equipment, we daily
Monitor Trouble Ticket system with staffs that have privilege. We have done preventive
maintenance on some power devices like power circuit, transformer and heater.

2.7 Challenges faced and measures

2.7.1 Challenges

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The COVID 19 pendemic has upended the spring academic semester for our country ,also
significantly affected our internship and our job plane because of this virus we had no more
proper time to spend more time to practice our theoretical skill to practical .
In addition to as we know we are an extension student we learning by supporting our selves by
working. There were some challenges we had faced in the internship period. The great problem
in the internship period in AMIMTDE

 There are no enough written documents to read about the overall system operation and
device except some equipment manuals.
 The company workers are busy and mostly they spent on field work. And sometimes it is
difficult to get the right persons for a particular device. Usually they didn‟t give us
specific and regular task and most of our task were observing when they did their work.
 They didn‟t provide necessary material for work like data, structural work flow and most
had no any awareness about the university internship program. When faults are created
we may know the source of the fault or where the problem is created but, to maintain it is
necessary to get appropriate material and permission from the right persons.

2.7.2 Measures taken to overcome the challenges

Those challenges by preparing ourselves due to COVID 19 by using some prevention method.
Like wiring masks properly eye glass, using hand sanitizer alcohol and making our social
distance everywhere. Most of the challenges we mentioned above were difficult to overcome.
Even though we tried to reduce the challenge by creating smooth and peace full conditions with
workers, by being voluntary doing labor tasks, by maintaining work ethics. And we tried to
create awareness about the internship program. We tried to understand the working principle of
the device by asking the workers and by searching internet. Regarding on protected and secured
equipment‟s we tried to look some of the detail of its parts from the old or use less equipment‟s
that are found in store house. When faults created outside the city we tried to walk together with
workers and look the fault and maintenance.

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 CHAPTER THREE

3. Benefits Gained from the Internship

3.1 Upgrading theoretical knowledge and Improving Practical skills

In internship program we have get the opportunity to apply our theoretical knowledge in real
world environments. Frankly speaking, our theoretical knowledge got strengthen more by those
practical techniques invested on this internship.

This internship period was a good filed to read about real world problems how to solve it in
engineering departments. Therefore, we gained the following essential things:

➢ Creative and logical approach to solving problems

➢ Clearly understand different network device and how to configure them

➢ We can understand and practice how system design and implement

➢ We were able to apply our basic knowledge to design and implement AMIMTDE

3.2 Improving team playing skills

In this company most of the works are done in group. Working together is essential to solve
problems, so it was a good opportunity for us to develop team playing skill. The most important
point in team playing skill is just reach an agreement from different points on the work to be
done. Being positive thinker and having rational reasoning skill is the basic points to understand
each other.

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By working together, we improved our practical and theoretical knowledge, problem solving
skill, communication skill, and social interaction. And also we had observed methods how to
handle challenges and failures that might happen in different aspects. Working together often
leads to increase outcomes of the work.

Team work, especially for engineers is important and involves in every piece of task. Thus, gaining
good team playing skill has been essential for effective completion of the given task. As team
member someone contribute a lot in many ways to improve individual communicative knowledge of
solving the existing problem. Because of these team members we can improve the following
attributes:

➢ Ability of problem identification for solving those problems

➢ Selecting the most appropriate method to solve the existing problem.

➢ Generating or forwarding flexible permissions to solve the problems raised.

➢ A good decision maker.

➢ Accomplishing tasks quickly with as its schedule.

➢ To perform quality work and save time team work is very important in our internship program
and for future.

3.3 Improving interpersonal communication skills

In this internship period we have got a lot of experience and benefit of interpersonal skill .We
became familiar with work environment, time management, work ethics and relation between the
co-workers, practical and theoretical knowledge, and communication skill. It is essential in order
to get information about the work, experience sharing and to create good environment for work.
We developed self-confidence, freely expressing our opinions. Generally we gained important
communication skill from internship.

During the internship period we recognized that team work is necessary for a given task to be an
accomplished early and qualitatively. Individuals often learn different things from colleagues
through communication. For any individual‟s communication is an important way of learning,

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which can be defined formally as the act, process, or experience of gaining knowledge or skills.
Communication and the subsequent learning help individual especially engineers more allow
them to gain new professional knowledge and abilities. Good communication is the life hood of
the engineering profession. Even though, it takes many forms, such as speaking, writing and
listening, it has the following usage:

➢ To exchange new ideas and knowledge with the other

➢ Improve to build up self confidence

➢ It improves our speaking and listening skills

➢ To solve the problem in with others.

➢ Improve relationships with the other.

3.4 Leadership skills

Leadership roles not just in a work environment, leadership skills can be applied to any situation
where you are required to take the lead, professionally, socially and even at home. Generally
directing successful leadership results in the employee growth and development with new skills
and capabilities that enables to increase the productivity.

As we are being a trainer the tasks assigned to us was not much leadership. We had been working
with supervisor and we made contact with different workers. But, we have learnt that the way how
the leaders lead their respective teams, some of important points we have noticed from the leaders
are: the ability to encourage and motivate workers, the ability to communicate with all workers, the
ability to listen problems raised from the team and focus on its solution, willingness to admit and
learn from failures and weaknesses, and the ability to have defined goals, missions and vision.

A person who is in the position of leadership should be smart enough to manage those
individuals whom he/she is leading. Leadership is a skill to guide, control and monitor people.
This shows that we take a lot of experiences from their leading. They control each employee in
their day to day activities. That means we got the chance to saw the strength and weakness of
each leader. We have gained the following benefits which improved our leadership skills:

➢ Committed to the work

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➢ Understanding others idea

➢ Peaceful with others

➢ Be honest to the job and other employee

➢ Take care for other.

➢ Help each other.

➢ Get knowledge from the other.

➢ Upgrading with knowledge etc.

3.5 Over All Achievements of the Intern

During our stay in the company we gain valuable work experience that should enhance our
academic preparation. Thus we can say we have become familiar with the working environment
and work of conduct which enables us to posses‟ appropriate behaviors with coworkers and the
supervisor. We were always on time because we know the importance of keeping time, being on
time is something that is very strongly stressed at AMIMTDE. Generally it opens the door to get
ready for the next steps to take job for our life career.

CHAPTER FOUR 4. CONCULSION AND RECOMMENDATIONS

4.1 CONCULSION

The history of AMIMTDE shows how the political, environment, national development policies, and
socioeconomic order have influenced the growth of the metal. Despite the resource and policy
constraints that the AMIMTDE has endured in the past, there has been considerable progress.
AMIMTDE requires enormous resources and strong determination to build and operate an
efficient and modern agricultural infrastructure. The task is further complicated from day to day
as demand increases continuously and new services are expected by the ever increasing number
of users.

We concluded that the program is very good to know the real world life and work way
comparing with class study subjects.

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We can say that this internship was successful by acquiring sufficient knowledge and practical
skills. Here during this period (as an intern) the hosting company satisfied with the activities of
our performance especially theoretical understanding in every moment.

On the internship period, we have understood so many skills that was the job environment and
what it meant to be a worker, what and why ethics we need to have at the work place and outside.
It was also very effective in developing team playing, interpersonal and leadership skills.

We observed how to operate, monitor and maintain different types of power devices. We became
familiar with working environment, organization culture, and different electrical equipment.

Generally, we get satisfactory knowledge and more benefited at internship period. This internship
program is real, necessary and important to Electrical engineering students.

4.2 RECOMMENDATIONS
4.2.1 Recommendation for the Company

There are many preconditions that should be fulfilled to the interns for internship program to be
more effective from all sides of the concerned body, the institute and the hosting company. First
of all the company and the university should work together to create awareness about the
internship program.

However, we would like to recommend it based on our observation while we was conducting the
internship program. Thus recommendations are as follow:

➢ The Company should be ready for internship students by preparing project tasks and
motivations to achieve this internship program.

➢ There is no research and development department, this cause the workers to have less
sense to upgrade their knowledge and improve this company

➢ The company worker is considering that internship student is not perform any task and
they are not known in the company

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➢ The company must be managing and arrange the time to do different task in rotation,
rather than perform single task during internship period.

➢In our internship period we have seen many devices that have no function like generators,
transformer, different switches and other many devices. So, it will be better, if AMIMTDE
implement workshops to maintain equipment‟s like in addition to replacing. As a result, the
company can save lots of money for the purchasing of new materials or devices.

➢When the main power source is not available mostly the AMIMTDE uses the generator as
alternative source. But the generators have many different side effects like noise, environmental
pollution, fuel consumption, interruption due to many reasons and other. As result we
recommended for the company to use other alternative power source like sun light because, from
sun light we can get many advantage. From sun light we can get clean, cheap, uninterruptable,
sound free and pollution free dc power.

➢In our internship period we have seen that many types of sensors that installed in AMIMTDE
but most of them didn‟t work properly due to many reasons. For example the fuel tanks of old
generators didn‟t have level sensors. As a result workers lose their time by manually checking
fuel level. But if they install fuel level sensors they can save time and solve interruption of
generator having no fuel in the tank for the company. So we recommended for the company to
install and maintain different type‟s sensors. If the sensors work properly AMIMTDE can save
money, time and reduce network interruption on this big company.

➢Finally I would like to recommend, this company have no power bank so guess how much
energy will be lost in one year.

4.2.2 Recommendation for Faculty

The Faculty of Electrical and computer make opportunity and communications with any
company to arrange the student to well know company. The schools must arrange before
internship period, to visit some company to reduce any confusion during learning time. Specially
Electrical Engineering student in get problem during ask any support from the company workers
because as we know all in Ethiopia Electrical system somewhat very sophisticated so the worker

35
of company is afraid in order to support for Electrical Engineering students so the main difficult
to communicate so that faculty must communicate with company in order to solve such problem.

And finally it is good to enforce the company to give a specific task, project and responsibility
and management to the intern.

4.2.3 Recommendation for Industrial Linkage


The University Industrial Linkage office should send request or announce to the
companies earlier to the internship period so that the company will have reserve place to
the intern to host him/her.


It is better to automate the interaction between the Industry Linkage and companies.
Hence it is time for the internet communicating with mail will reduce paper transfer b/n

them and it is also essential to save time for the interns.


Finding space for internship program for students is difficult due to many reasons. For
example, most of the company didn‟t want to accept the students. So, we recommended
for Industry Linkage to find space from different companies and industries of the country
for the interns. But as we remember it was challenged and difficult to inter in to our

interest due to the retardation of UIL.

In addition to this the University Industrial Linkage should create awareness for private
and governmental organizations how this internship program is very useful to our country and
other concerned people using possible means of communications inc luding
advertising in media.

Generally, the benefit of this internship program for producing efficient engineers is
unquestionable if properly held.

36
 REFERENCE

1. Stephen J. Chapman, “Electrical fundamental machinery”, McGraw-Hill, 5th edn. 2012

2. B.L.THERAJA “Text book of Electrical Technology”,vol II

3. J.DUNCAN GLOVER, MULUKUTLA S.SARMA and THOMAS J.OVERBYE, “Power

th
system analysis and design” UNIVERSITY OF ILLINOIS, 5 edn. 2012.
4. D P Kothari, I J Nagrath et.al, “Electrical Power Systems”-C L Wadhwa-4th edition 1985

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