1. Presentation on
ME-370 : Industrial Training
Industry General Electric Manufacturing Company Limited
Trainee Students:
• DIPEN SHOME ( 20110037 )
• MAHBUB REZA CHOWDHURY ( 201110114)
• TUSHAR NATH (201110166)
• SALAHUDDIN AHMED (201110156)
2. Introduction
• General Electric Manufacturing Company, popularly known as GEMCO,
is the one of the leading transformer manufacturing companies in
Bangladesh.
• As an enterprise of Bangladesh Steel and Engineering Corporation
(BSEC), it was emerged as “Public Limited Company” in 1979 and
renamed to “General Electric Manufacturing Company Limited”.
• Located at North Patenga of Chittagong, it was established in 1967 under
supervision and with financial and technical aid from the-then United
States of Soviet Russia (USSR).
3. Industry at a glance:
• Industry Complex Area: 100 acres
• Production of Transformers comprises of Two Units:
- General Production Building ( Mechanical Section)
- Main Building ( Electrical Section)
4. Industry at a glance:
• Production Cost: 53 Crore BDT
• Administrative Cost: 6 Crore BDT
• Distribution Cost: 1.5 Crore BDT
• Research & Development: 3.5 Lakh BDT
• Installed Annual Production Capacity of the Industry : 6923 M.Tons
• Average Monthly Electricity Consumption : 50000 KWH
Approximate Cost in 2014-2015 Fiscal year:
• Attainable Annual Production Capacity: 1850 M. Tons or equivalent of
1875 No. of 200 kVA Transformer
5. • GEMCO is now manufacturing and supplying a major portion of Electrical
Distribution equipment required by the power sector of the country.
Products/Services
• Currently following products are being manufactured in the industry:
i) Transformers:
• Distribution Transformer, 3 Phase, 11/0.415 KV, 50 KVA to 500 KVA
• Distribution Transformer, 1 Phase, 6.35/0.24 KV, 5 KVA to 25 KVA
• Distribution Transformer, 1 Phase, 11/0.24 KV, 15 KVA to 25 KVA
6. • These products are supplied to various Government and Non-Government
agencies like Bangladesh Power Development Board (BPDB), Dhaka Power
Distribution Company Limited (DPDC), Dhaka Electric Supply Company
(DESCO), West Zone Power Distribution Company Limited (WZPDCL) etc.
ii) Other Electrical Items:
• Drop out Fuse, 11 KV
• Lightning Arrestor, 11 KV
Products/Services
7. Raw Materials
Name of Raw
Materials
Specification of
materials
Source Foreign/
Local
Average Yearly
Consumption
Silicon Steel Sheet Grade M-5 Foreign 500 M.Tons
Copper Strips Electrolytic Copper of
99.9% purity
Foreign 100 M. Tons
Super Enamelled
Copper Wire
SWG -14 to 21 Copper of
99.9% purity Local 150 M.Tons
M.S. Sheet Prime Quality Local 200 M.Tons
HT Insulator Electrical Porcelain
Insulator
Local 5000 Pcs.
Transformer Oil As per IEC-60296 Class-1 Foreign 2500 Barrel
Insulated Paper &
Board
Electrical Grade 100%
Sulphate/Kraft Pulp Foreign 30 M. Tons
Oval Pipe 45x18x1.5xLength mm Local 50,000 meter
MS Channel 7.5/10cm Local 50m Ton
8. Manufacturing Process
• the construction of “Tank” (transformer body),
• making of “Core”
• winding of High Tension (HT) and Low Tension (LT) Coil etc.
The overall manufacturing process can be divided into two categories:
The complete manufacturing of Transformer includes
9. the process of shaping raw materials (cutting,
shearing, bending etc.)
fabrication of ‘Transformer’ body (known as
‘Tank’)
Radiator
Painting of ‘Tank’
Manufacturing Process : Mechanical
10. Manufacturing Process of Transformer Body:
Mechanical Manufacturing Process can divided into 3 portion:
Mechanical
Manufacturing
Construction of
(i) Transformer body
(ii) Radiator
(iii) Conservator
Leak
Testing
Painting
Manufacturing Process : Mechanical
11. a. Construction of Transformer body
(i) Tank:
It is the main body of a transformer which accommodates Transformer Core (HT
and LT Coils) and Cooling Fluid (Transformer Oil).
Manufacturing Process : Mechanical
12. • The construction process is initiated by straightening Mild Steel (MS)
sheet in a “Straightening Machine”
• A “Hydraulic and Pneumatic Type” Shearing Machine is used to cut these
sheet metal and produce a desired shape.
• For producing the side half cylindrical surface of the Tank, a Pneumatic
Bending Machine is used. The sheet is inserted between the dye and
punch.
• These parts are then welded (Electric Arc Welding) together in the
welding section.
Construction Process:
Manufacturing Process : Mechanical
13. (ii)Radiator:
When high current passes through the core of a transformer it produces
excessive heat which in turn increases the temperature of transformer oil. Oil
is circulated through the radiator which is exposed to the atmosphere. Thus
the radiator of transformer accelerates the cooling rate of transformer.
Construction Process:
• Oval shape pipe of Mild Steel are arranged vertically and parallel to each
other and welded to the crates which acts as an interlink between Tank
and Radiator.
Manufacturing Process : Mechanical
14. (iii) Conservator:
When the temperature of the oil is raised due to Joule Heating, it expands
and vaporizes. This oil vapor causes corrosion to the transformer body and
core components. A conservator tank of transformer provides adequate
space to this expanded transformer oil (and vapor). It also acts as a
reservoir for transformer insulating oil.
Manufacturing Process : Mechanical
Construction Process:
• In a Hydraulic Rolling Machine, Mild Steel
sheet is given cylindrical shape.
• The gap between two edges is welded by
Electric Arc Welding.
• Two circular metal plate produced in “Dye-
Punch machine” are welded with this part to
complete the manufacturing of Conservator.
15. b. Leak Testing:
• It is used to detect the leakage of oil in Tank during its operation in future.
• A testing bath is used for leak detection of the tank and the radiator.
• The Tanks with Radiators are immersed in a water tank and compressed
air is passed into the tank.
• If bubbles are produced there is leakage and the bodies are sent for
repairing purpose otherwise these are sent to the painting shop for
painting purpose.
Manufacturing Process : Mechanical
16. Before Painting, a batch of transformer body is inserted into a “Shot Blasting
Machine” to remove irregularities if there is any.
The painting of the tank is accomplished in two steps:
• The inner side of the tank is painted with “Oil resistant” paint.
• The outer surface is first painted with “Red Oxide” for ensuring no corrosion
and then coated with “Ash Color” for beautification.
• After Painting is done, the body is heated to temperature of about 100-
120° C for about 2 to 2.30 hours.
• A Paint meter gauge is used to check whether the thickness of painting is
in the required range
Manufacturing Process : Mechanical
c. Painting:
18. • Core Material: Silicon Steel
• Shape: Angular Cut
• The “Core” is made by attaching the sheets one by one in an order of
decreasing dimension from mid-plane. So, at present angular cut sheets
are used for reducing losses.
• The reason behind using “Angular Cut” shape instead of “Straight Cut” is to
reduce “Eddy Current Loss”
a. Making of Core:
Manufacturing Process : Electrical
19. Manufacturing Process : Electrical
b. HT and LT Winding:
(i) HT Winding: (for 200kVA Transformer)
• HT Winding Machine is used in producing HT Coil.
• HT Coil Material: SWG-15 Wire
• Total Layers: 11 (separated by Paper Insulation)
• Total Active Turns: 2163
• After certain number of turns, a wire is brought out to be connected with
the “Tap Changer” which acts as ‘’Voltage Regulator”.
(ii) LT Winding: (for 200 KVA Transformer)
• Copper Strips (3.1 x 7.7 cm) are wounded around a bobbin in a LT
Winding Machine.
• Number of Layers: 2
• Turns in Each layer: 23
• Cardboard strips are inserted between two layers.
• Cardboard Strip Thickness: 2mm
20. Manufacturing Process : Electrical
c. Insulation of HT and LT Coils:
Insulation is provided
• to avoid direct contact between core and coil
• to maintain separation between different layers of coil.
Two types of insulation are provided:
(i)Wood insulation:
• Wood insulation is provided so that the current passing through the core
doesn’t get shorted with the tank
• Using a dye, a half round shape is given to the cardboard because the
Core is flat and the coils are round in shape.
(ii)Paper Insulation:
• Paper insulation is provided in LT Coils.
• A “Lapping machine” is used where copper strips pass through a middle
channel and two tilted wheels rotate on either side of the channel. As the
strips pass around the wheels, these get wrapped with paper insulation.
21. Manufacturing Process : Electrical
d. Inserting LT and HT Coils to the Core:
• Firstly Paper insulation is provided around the Core.
• Secondly, Low Tension Coil is fitted around the “Core” and the terminals
which were brought out after certain turns are kept isolated.
• Thirdly, High Tension Coils made of Super Enamel Wire are fitted around
the core along with LT Coils.
• Finally, a board insulation and 10 mm wood insulation is provided
between the Yoke Beam and coils in bottom side and a 30 mm Wood
insulation on the top side.
• Thus the final assembly is made ready to get inserted.
23. Manufacturing Process : Electrical
(i) HT Soldering:
• In HT Side, a Delta Connection is established.
Innermost coil of HT Side = Start
Outermost coil of HT Side = Finish
• The coils are soldered in such a way that the finishing point of one coil
gets connected with the starting of another.
• The remaining terminals are connected to the tap changer to regulate
voltage.
e. Soldering of Coils:
• Phase to Phase Voltage: 11KV
24. Manufacturing Process : Electrical
(ii) LT soldering:
• A Wye (Y) connection is established in LT Side.
• One end of each LT Coil is connected together and this is connected to the
Neutral terminal.
• These coils are soldered in such a way to make sure that they constitute a
Wye (Y) Connection. The other terminals are Phase Terminal.
• Phase to Phase Voltage: 415 V
• Phase to Neutral Voltage: 220 V
26. Manufacturing Process : Electrical
(f) Fitting Active Body into the tank:
• Tank is dried for 48 hours before it is fitted inside the tank.
• A rubber gasket is used to seal it completely from air and water.
(g) Filling the Tank with Transformer Oil:
• After the final assembly is completed, the tank is filled with viscous oil
until it occupies the half of the conservator volume.
• An indicator is used for this purpose.
27. Manufacturing Process : Electrical
(h)Testing:
For confirming the specifications and performances of an electrical power
transformer it has to go through numbers of testing procedures.
(i) Megger test:
This test is performed to check
• Insulation between HV Coil and LV Windings
• Insulation between HV Coil and “Tank”
• Insulation between LV Coil and “Tank”
(ii) Power Frequency Withstand Test:
• It is intended to check the ability of maintaining insulation to earth and
between windings.
• This is test is performed in both HT and LT Side.
(iii) Induced Over Voltage Test:
This test is intended to check the inner turn and line end insulation to ground
and between Windings.
28. Manufacturing Process : Electrical
(iv) Ratio test:
• This test is performed to find out the turns ratio at different tap position.
(v) No Load test:
• This is done to determine “Core Loss” on XFR.
(vi) Full Load Test:
• This test determines the Copper Loss in the Transformer.
(vii) DC Resistance Measurement Test:
• This test is performed to detect any problem in the soldering and at which
portion the problem occurs.
(viii) Vector Group Test:
• A-a is shorted and 400V is applied on HV side(ABC).
• Voltage across C-c, B-c and C-b are determined.
29. Some Important Sections of the Industry
Administrative Section:
• The administration department is responsible for the general running of the
organization.
• It also provides administrative and logistical assistance to all departments of
the industry.
Officer Staff Worker Total
36 69 213 318
Human Resource:
31. Some Important Sections of the Industry
Maintenance Section:
• The function of this section is to repair all kinds of machines in case of
sudden failure (Mechanical and Electrical).
• This section is also responsible for maintaining a Constant Voltage and
Current Ratio
Accounts Section:
This section monitors the overall cost of the industry and determine the profit or
loss. Different costs of the industry include raw material cost, labour cost,
employees salary, manufacturing overhead, Power consumption cost etc.
32. Some Important Sections of the Industry
(ii) Sales:
• This section handles the selling activities of the industry.
• The major customers of the industry are BPDB, DESCO, DPDC etc.
• They have a direct procurement method to deal with BPDB. As this method
does not allow open tender system so there is no scope for BPDB to deal with
lowest offered price among transformer producing companies.
• The selling price of the transformers of this industry is higher than other
transformers available since they maintain very good quality.
(i) Purchase:
• This section handles the purchasing
activities of the raw materials of the
industry.
Marketing Sections:
33. Conclusion:
The industrial training was a great opportunity for us to acquire practical
knowledge of production processes of an industry and we were able to learn how
our theoretical knowledge can be applied in industrial field. We gathered vast
experience on the process of 3 phase distribution transformer production. We
realized that there are some differences in theoretical and practical knowledge
which will help us in the future in our job life. From our observations we realized
that if Bangladesh government takes adequate steps and invest sufficiently in this
industry it can be one of the leading transformer manufacturing company in the
country. Most of the highly productive machines of the industry are not in
operation which is a matter of sorrow. By taking proper steps to use these
machines efficiently the company can increase its production efficiency.
Government should also take steps to export the highly reliable transformers of
the industry to foreign countries which will create a large market for the products
of the industry.
