1. INTERNSHIP REPORT
on
(Schneider Electric Pakistan)
Shiraz Ahmed Khan
Electrical Engineering Department
E-mail: shiraz_sherwani@yahoo.com
Mob: 0345-3958029
Duration Of Period: 17th Dec 2014 to 7th
Jan2015
3. ACKNOWLEDGMENT:
First of all I want to thanks The Almighty Allah, who gave me this great opportunity to be a part
of such a great Multinational Company as an internee and made me enable to learn a lot of
practical knowledge.
The successful compilation of this internship and report was possible due to help and support of
various people, who were there for me whenever I needed them. This includes first of all the
company, Schneider Electric itself, which gave me the opportunity to spend time in its highly
professional environment and gave me all the opportunities to learn.
I would like to thank Mr. Salman Hakkani and Ms. Nida Javed, Human Resource Department,
Mr. Farhan Rajput Inspection and Testing Department for giving a lot of knowledge as a Testing
Engineer, Mr. Saqib Design Engineering Department for their kind support and guidance, Mr.
Omair Sheikh and Ms. Shana Production Depart, I am also thankful to Mr. Saad Ahmad Zia
Head of Final Inspection and Testing Department along with the whole staff for giving me an
opportunity to learn and gain hand-on experience in the factory. Whole technical department has
been very supportive during my internship. It will surely be a lifetime remembrance for me and I
feel privileged working with such committed and elegant engineers and staff. I would also like to
thank all the workers who had cooperated a lot throughout my internship.
Shiraz Ahmed Khan
4. PREFACE
Internship is the intermediate step of an engineering student's academic career. For a student of
the Department of Electrical Engineering, training is essential for the complete understanding of
the concepts learned from formal education. There remains a huge gap between academic
learning and the implementation of that hypothetical knowledge in the practical world of modern
Engineering. Internship can compensate this wide gap as it brings opportunities for a student to
comprehend the main trends of engineering activities.
In compiling this report I have intended to provide a synthesis of theoretical approaches and
methods of implementing them in the world of engineering. I have tried to discover the relationship
between theoretical and practical type of knowledge. I have tried to bridge the gap between
theoretical assumptions and practical necessities. During the entire course of our academic study
we remain engaged in theoretical learning where the primary objective is academic success. A
concise knowledge of the modern engineering arena can only be attained through the pragmatic
implementation of hypothetical ideas, which we learn from our academic activities.
With these objectives, I have made all possible efforts and the necessary investigations to submit
this paper in an enlightened form in a very short time. I have tried my level best to eliminate errors
from the paper. As I had to complete my internship within a short period of time so the study
admits its limitations.
I visited the Schneider Electric as a part of the internship program starting from 17 December
2014 to 07 January 2015.
5. Overview of the organization
Health, Safety & Environment
For Schneider Electric Private(LTD),Karachi Pakistan. Health, Safety & Environment possess
utmost significance. The company ensures that:
manner acceptable to the local communities.
deliberate harm, damage or loss.
To make sure that these guidelines are followed, the company provides Safety, Security, Health
& Environment training and information to all employees, contractors and others who work with
Schneider Electric or handle their products.
Schneider Electric’s Brief History
Schneider Electric SE is a European multinational corporation that specializes in electricity
distribution, automation management and produces installation components for energy
management. It is headquartered in Rueil-Malmaison, France and is also based at the World
Trade Center of Grenoble.
As a global specialist in energy management with operations in more than 100 countries,
Schneider Electric offers integrated solutions across multiple market segments, including
leadership positions in energy and infrastructure, industrial processes, building automation, and
data centers/networks, as well as a broad presence in residential applications. Focused on making
energy safe, reliable, and efficient, the company's 100,000+ employees achieved sales of more
than 15.8 billion euros in 2009, through an active commitment to help individuals and
organizations “Make the most of their energy”.
Products:
1. Access to Energy Collective Solutions 2. Access to Energy Home Systems
3. Audio-Video Solutions
4. Boxes, Cabling & Interfaces
5. Building Management System
6. Busway & Cable Management
7. Contactors & Protection Relays
8. Cooling Solutions
9. Cyber security Solutions
10. Data Centers and Server Rooms and Network Closets
11. Din rail modular devices
6. 12. Distribution and communication systems
13. Emergency Lighting
14. Energy Management Services
15. EVlink charging solutions for electric vehicles
16. Feeder Automation
17. Fuse Switches
18. HMI (terminals and industrial PC)
19. Home Control
20. IED User Software
21. Industrial & Specialized UPS and Power Conversion
22. Industrial communication
23. Industrial plugs and sockets
24. Installation material
25. Insulation monitors
26. Interface, Measurement & Control Relays
27. IT Power Distribution
28. IT Racks and Accessories
29. IT Services
30. Motion & Drives
31. Motor Starters
32. MV Circuit Breakers & MV Contactors
33. MV Disconnectors, Switches, Switch-Disconnections, Reclosers
34. MV Instrument Transformer
35. MV Switchgear
36. MV Transformers
37. MV/LV Prefabricated Substations
38. Network Connectivity
39. Network Management Software
40. PAC, PLC & other Controllers
41. Panel boards & Switchboards
42. Power & Energy Monitoring System
43. Power Circuit breakers & Switches
44. Power Quality
45. Power supplies & transformers
46. Protection Relays by Application
47. Protection Relays by Range
48. Pushbuttons, Switches, Pilot Lights, Control stations & Joysticks
49. Security and Environmental
50. Sensors & RFID system
7. 51. Signaling Units
52. Software
53. Solar for Ground Mounted Plants
54. Solar for Industrial & Commercial Rooftops
55. Solar for Residential
56. Solar Off-Grid and Back-up
57. StruxureWare for Data Centers
58. Surge Protection and Power Conditioning
59. Systems and architectures
60. Telemetry & Remote SCADA Systems
61. Telemetry System
62. Uninterruptible Power Supply (UPS)
63. Universal Enclosures
64. Weather Observation Hardware
These are the main products of Schneider Electric ,globally. These are further divided into too
many sub classes.
8. ORGANIZATIONAL STRUCTURE:
PROCESS WORKFLOW:
The process workflow in Schneider Electric starts from the meeting of client with the member of
Sales department agreeing on a particular order including numerous items. The department P1
i.e. of Instruction and Planning took over the order and is responsible throughout the completion
of the project. Meanwhile a Project Manager is assigned who act as a person to whom the client
will be discussing the needs and objective of the project. The Project Manager guides the client
with its available design of the project and making necessary changes in it. Once the design is
approved by the client, instruction come from Planning department to fetch Pre-fab plans, Job
cards and MPS (Material Preparation System). The workflow continues with the job study and
internal planning of P31 i.e. Fabrication department which includes drawing study as given by
the Design department , Job card verification and PDF formation. Internal verification is carried
out which include article verification, machine utilization, meeting desired targets and accessing
all raw material required.
With these target achieved, the material begin to be prepared which include raw materials such
as sheet, copper and paint. The making of these materials run through the process of punching,
bending, welding and paint, finally setting a prerequisite need of the completion of the project.
Once the design is fabricated by the Fabrication department, the work of P6 i.e. Drawing office
starts with the implementation of design as approved by client and making necessary changes in
it. The Single line diagram (SLD) is drawn by the designer on a software E3 and all possible
views of the project is implemented on AUTOCAD software. The designer provides the design
to the Production department ready to implement the design.
Production department is responsible for carrying out the production and assembling of the parts
required in the project. The workers according to the instruction implement the design and
assemble the parts required, the wireman implement wiring according to SLD and finally the
project is forwarded to the WIP inspector to investigate the design. The final inspection is
carried out by Testing and Inspection department which include Quality persons keeping a check
in balance of the quality of the material used.
The project then is handed over to Logistics and kitting is done before delivering to the
transporter for the final delivery.
Hence, from the placement of order of client to the delivery of the order, the Project Manager is
responsible for completion of the project well on time. Moreover he/she act as a person who
fulfill all the needs and changes made by the client during the project and informing them to all
the department engaged in the project in the company.
10. TRAINING PROGRAM:
The training program at Schneider starts with the Fabrication department where Mr. Babar took
over my supervision. He surveyed the process of fabrication to me which runs throughout the
company. The fabrication of the electrical equipment includes:
a) PUNCHING MACHINE:
The metal sheet remained same for LV as well as for MV. These sheets are brought into
the CNC (Computerized Numeric Control) machine where the programmer through
programming made the outfit, punches and holes in the metal sheet.
b) TAG IDENTIFICATION PART:
Once the punches and holes are made into the sheet, tags are put up so as to identify
which part is used to specify which part.
c) BENDING:
Bending of the sheet is done manually. It has lot of variation. Its basic purpose is to give
particular angle to the shape.
d) WELDING:
Welding is done on the sheet wherever necessary and the shape is ready to be painted.
e) GALVANIZING:
There are some part in the design which are actually moving parts and because of their
motion , the paint may be flaked off. So in order to avoid that, galvanizing is done on the
moving part, this reduces the wear and tear of the design.
f) PAINT:
Painting are of two types:
Wet paint
Powder paint
Wet paint takes more time to dry as compared to powder paint. Here in Schneider Electric,
powder paint is mostly done on stationary part which runs through following processes:
i. PRE-CLEANING:
The design is cleaned before it is being painted with Zinc Phosphate ZnP
to clean oily surface and to increase the adhesive property for painting.
Zinc Phosphate is sprayed by high pressure nozzle so as to avoid rusting
during transportation.
11. ii. DRYING:
Once the design is pre-cleaned by Zinc Phosphate it is dried by blowing
air onto it.
iii. POWDERING:
Powdering is done by using powder gun on the design. Powder impact are
of two types, one which have textures which is mainly used for rough
surface and the other one do not have textures which is used for plain
surface. The powder paint having textures is better and recommendable
for better paint.
iv. OVEN/MELTING OF POWDER:
Normally the powder sprayed on the design is melted at 180o
C in an oven
which was actually designed to run on 200o
C. The purpose of melting is to
have proper paint surface.
In the Production department, I was accompanied by Mr. Umair and Mr. Ahsen, who gave
information about electrical equipment which are being used in the industry whose description
are as follows:
ELECTRICAL SWITCH GEAR:
Electrical switchgear is a generic term which includes all the switching devices associated with
mainly power system protection. It also includes all devices associated with control, metering
and regulating of electrical power system. Assembly of such devices in a logical manner forms
switchgear.
A switch gear has to perform the function of carrying, making and breaking the normal load
current like a switch and it has to perform the function of clearing the fault in addition to that it
also has provision of metering and regulating the various parameters of electrical system. Thus
the switchgear includes circuit breaker, transformer, protection relay, measuring instrument,
electrical switch, miniature circuit breaker, lightening arrestor or surge arrestor, electrical
isolator and other associated equipment.
MV SWITCHGEAR PANEL TYPES:
Schneider Pakistan manufactures panels related to Medium Voltage (MV) in Pakistan.The main
task of medium-voltage switchgear is cost-efficient and safe power distribution. Schneider's
Medium Voltage Switchgear provides centralized control and protection of medium-
voltage power equipment and circuits in industrial, commercial, and utility installations
involving generators, motors, feeder circuits, and transmission and distribution lines.
12. Schneider Pakistan produces many types of MV Panels, but most common and wanted products
of Schneider are listed below:
PIX
RK
WKK8
RK type MV panels are mainly used by WAPDA in which the vacuum circuit breaker usually
comes out with the door. On the contrary WKK8 is a standard product for K-Electric in which
the trolley of vacuum circuit breaker come out after opening the door. PIX is commercially
offered by Schneider for local use having microcontroller based programming
CIRCUIT BREAKERS:
Electrical circuit breaker is a switching device which can be operated manually as well as
automatically for controlling and protection of electrical power system respectively. It mainly
consists of fixed contacts and moving contacts. In normal “on” condition of circuit breaker, these
two contacts are physically connected to each other due to applied mechanical pressure on the
moving contacts. There is an arrangement stored potential energy in the operating mechanism of
circuit breaker which is realized if switching signal given to the breaker. The potential energy
can be stored in the circuit breaker by different ways like by deforming metal spring, by
compressed air, or by hydraulic pressure. But whatever the source of potential energy, it must be
released during operation. Release of potential energy makes sliding of the moving contact at
extremely fast manner. All circuit breaker have operating coils (tripping coils and close coil),
whenever these coils are energized by switching pulse, the plunger inside them displaced. This
operating coil plunger is typically attached to the operating mechanism of circuit breaker, as a
result the mechanically stored potential energy in the breaker mechanism is released in forms of
kinetic energy, which makes the moving contact to move as these moving contacts mechanically
attached through a gear lever arrangement with the operating mechanism. After a cycle
of operation of circuit breaker the total stored energy is released and hence the potential energy
again stored in the operating mechanism of circuit breaker by means of spring charging motor or
air compressor or by any other means. Moreover the circuit breaker has to carry large rated or
fault power. Due to this large power there is always dangerously high arcing between moving
contacts and fixed contact during operation of circuit breaker. The arc in circuit breaker can be
quenching safely if the dielectric strength between the current carrying contacts of circuit
breaker increases rapidly during every current zero crossing of the alternating current. The
dielectric strength of the media in between contacts can be increased in numbers of ways, like by
compressing the ionized arcing media since compressing accelerates the deionization process of
the media, by cooling the arcing media since cooling increase the resistance of arcing path or by
replacing the ionized arcing media by fresh gasses. Hence a numbers of arc quenching processes
should be involved in operation of circuit breaker.
13. o TYPES OF CIRCUIT BREAKERS:
According to their arc quenching media the circuit breaker can be divided as-
Oil circuit breaker.
Air circuit breaker.
SF6 circuit breaker.
Vacuum circuit breaker.
OIL CIRCUIT BREAKER:
Mineral oil has better insulating property than air. In oil circuit breaker the fixed contact and
moving contact are immerged inside the insulating oil. Whenever there is a separation
of current carrying contacts in the oil, the arc in circuit breaker is initialized at the moment of
separation of contacts, and due to this arc the oil is vaporized and decomposed in mostly
hydrogen gas and ultimately creates a hydrogen bubble around the arc. This highly compressed
gas bubble around the arc prevents re-striking of the arc after current reaches zero crossing of the
cycle. The oil circuit breaker is the one of the oldest type of circuit breakers.
AIR CIRCUIT BREAKER:
This type of circuit breakers, is those kind of circuit breaker which operates in air at atmospheric
pressure. After development of oil circuit breaker, the medium voltage air circuit breaker (ACB)
is replaced completely by oil circuit breaker in different countries. But in countries like France
and Italy, ACBs are still preferable choice up to voltage 15 KV. It is also good choice to avoid
the risk of oil fire, in case of oil circuit breaker. In America ACBs were exclusively used for the
system up to 15 KV until the development of new vacuum and SF6 circuit breakers.
SF6 CIRCUIT BREAKERS:
A circuit breaker in which the current carrying contacts operate in sulphur hexafluoride or
SF6 gas is known as an SF6 circuit breaker. SF6 has excellent insulating property. SF6 has high
electro-negativity. That means it has high affinity of absorbing free electron. Whenever a free
electron collides with the SF6 gas molecule, it is absorbed by that gas molecule and forms a
negative ion. These negative ions obviously much heavier than a free electron and therefore over
all mobility of the charged particle in the SF6 gas is much less as compared other common gases.
Hence, for heavier and less mobile charged particles in SF6 gas, it acquires very high dielectric
strength. Not only the gas has a good dielectric strength but also it has the unique property of fast
recombination after the source energizing the spark is removed. The gas has also very good heat
transfer property. Due to its low gaseous viscosity (because of less molecular
mobility) SF6 gas can efficiently transfer heat by convection. So due to its high dielectric
strength and high cooling effect SF6gas is approximately 100 times more effective arc quenching
media than air. Due to these unique properties of this gas SF6 circuit breaker is used in complete
14. range of medium voltage and high voltage electrical power system. These circuit breakers are
available for the voltage ranges from 33KV to 800KV and even more.
VACUUM CIRCUIT BREAKERS:
A vacuum circuit breaker is such kind of circuit breaker where the arc quenching takes place in
vacuum. The technology is suitable for mainly medium voltage application. The operation of
opening and closing of current carrying contacts and associated arc interruption take place in a
vacuum chamber in the breaker which is called vacuum interrupter. The vacuum interrupter
consists of a steel arc chamber in the centre symmetrically arranged ceramic insulators. The
vacuum pressure inside a vacuum interrupter is normally maintained at 10 – 6
bar. The material
used for current carrying contacts plays an important role in the performance of the vacuum
circuit breaker. CuCr is the most ideal material to make VCB contacts.
The main aim of any circuit breaker is to quench arc during current zero crossing, by establishing
high dielectric strength in between the contacts so that reestablishment of arc after current zero
becomes impossible. The dielectric strength of vacuum is eight times greater than that of air and
four times greater than that of SF6 gas. This high dielectric strength makes it possible to quench
a vacuum arc within very small contact gap. For short contact gap, low contact mass and no
compression of medium the drive energy required in vacuum circuit breaker is minimum. When
two face to face contact areas are just being separated to each other, they do not be separated
instantly, contact area on the contact face is being reduced and ultimately comes to a point and
then they are finally de-touched. Although this happens in a fraction of micro second but it is the
fact. At this instant of de-touching of contacts in a vacuum, the current through the contacts
concentrated on that last contact point on the contact surface and makes a hot spot. As it is
vacuum, the metal on the contact surface is easily vaporized due to that hot spot and create a
conducting media for arc path. Then the arc will be initiated and continued until the
next current zero. At current zero this vacuum arc is extinguished and the conducting metal
vapor is re-condensed on the contact surface. At this point, the contacts are already separated
hence there is no question of re-vaporization of contact surface, for next cycle of current. That
means, the arc cannot be reestablished again. In this way vacuum circuit breaker prevents the
reestablishment of arc by producing high dielectric strength in the contact gap after current zero.
POTENTIAL TRANSFORMER:
Potential transformer or voltage transformer gets used in electrical power system for stepping
down the system voltage to a safe value which can be fed to low ratings meters and
relays. A voltage transformer theory or potential transformer theory is just like a theory of
general purpose step down transformer. Primary of this transformer is connected across the phase
and ground. Just like the transformer used for stepping down purpose, potential transformer i.e.
PT has lower turns winding at its secondary. The system voltageis applied across the terminals of
15. primary winding of that transformer, and then proportionate secondary voltage appears across
the secondary terminals of the PT.
CURRENT TRANSFORMER:
A current transformer (CT) is used for measurement of alternating electric currents. Current
transformers, together with voltage (or potential) transformers (VT or PT), are known as
instrument transformers. When current in a circuit is too high to apply directly to measuring
instruments, a current transformer produces a reduced current accurately proportional to the
current in the circuit, which can be conveniently connected to measuring and recording
instruments. A current transformer isolates the measuring instruments from what may be very
high voltage in the monitored circuit. Current transformers are commonly used in metering
and protective relays in the electrical power industry.
PROTECTIVE RELAY :
A relay is automatic device which senses an abnormal condition of electrical circuit and closes
its contacts. These contacts in turns close and complete the circuit breaker trip coil circuit hence
make the circuit breaker tripped for disconnecting the faulty portion of the electrical circuit from
rest of the healthy circuit.
MINIATURE CIRCUIT BREAKER (MCB):
Nowadays we use more commonly miniature circuit breaker or MCB in low voltage electrical
network instead of fuse.
The MCB has some advantages compared to fuse.
1. It automatically switches off the electrical circuit during abnormal condition of the network
means in over load condition as well as faulty condition. The fuse does not sense but miniature
circuit breaker does it in more reliable way. MCB is much more sensitive to over current than
fuse.
2. Another advantage is, as the switch operating knob comes at its off position during tripping,
the faulty zone of the electrical circuit can easily be identified. But in case of fuse, fuse wire
should be checked by opening fuse grip or cutout from fuse base, for confirming the blow of fuse
wire.
3. Quick restoration of supply cannot be possible in case of fuse as because fuses have to be
rewirable or replaced for restoring the supply. But in the case of MCB, quick restoration is
possible by just switching on operation.
4. Handling MCB is more electrically safe than fuse.
16. Because of to many advantages of MCB over fuse units, in modern low voltage electrical
network, miniature circuit breaker is mostly used instead of backdated fuse unit.
SURGE ARRESTOR:
A surge arrester is a device to protect electrical equipment from over-voltage transients caused
by external (lightning) or internal (switching) events. Also called a surge protection device
(SPD) or transient voltage surge suppressor (TVSS), this class of device is used to protect
equipment in power transmission and distribution systems.
ELECTRICAL ISOLATORS/ EARTHING SWITCH IN SWITCH GEAR:
Circuit breaker always trip the circuit but open contacts of breaker cannot be visible physically
from outside of the breaker and that is why it is recommended not to touch any electrical circuit
just by switching off the circuit breaker. So for better safety there must be some arrangement so
that one can see open condition of the section of the circuit before touching it. Isolator is a
mechanical switch which isolates a part of circuit from system as when required. Electrical
isolators separate a part of the system from rest for safe maintenance works.
DISTRIBUTION BOARDS:
A distribution board (also known as panel board or breaker panel) is a component of
an electricity supply system which divides an electrical power feed into subsidiary circuits, while
providing a protective fuse or circuit breaker for each circuit, in a common enclosure. Normally,
a main switch, and in recent boards, one or more residual-current devices (RCD) or residual
current breakers with overcurrent protection (RCBO), are also incorporated.
o TYPES OF DISTRIBUTION BOARD:
Light distribution board
Emergency distribution board
UPS distribution board
VARIABLE FREQUENCY DRIVES (VFD):
VFD is a power electronics based device which converts a basic fixed frequency,
fixed voltage sine wave power (line power) to a variable frequency, variable output voltage used
to control speed of induction motor(s). It regulates the speed of a three phase induction motor by
controlling the frequency and voltage of the power supplied to the motor.
:
17. CONCLUSION:
The organization provided interesting insight of how electrical equipment are assembled, tested
and forwarded to client. Simultaneously, it was a good opportunity to put in practice the
theoretical concepts learned during the academic year. Last but not least, it was a great
opportunity for developing personal intellectual skills, management skills and self-motivation to
work with a skillful and a hardworking team.
