INDUSTRIAL TRAINING REPORT

AT

Satna (M.P.)

FROM: 02-06-2012 TO: 06-07-2012

TRAINING IN-CHARGE:

Mr. Prakash Singh

Sub Divisional Engineer (SDE)

Universal Cables Ltd.

SUBMITTED BY:

Piyush Shukla (09502914)

Electronics & Communication Department

Jaypee Institute Of Information Technology, Noida

CONTENT

1. Acknowledgement

2. Declaration

3. Introduction

4. Description Of The Organization

5. Description Of The Work Carried Out

6. Manufacturing processes

7. Optical cables

8. Conclusion

ACKNOWLEDGEMENT

I feel profound pleasure in bringing out this projects report for which we have to go from pillar to post to

make it a reality.

This project work reflects contributions of our colleagues with whom we had long discussions and

without which it would not have been possible. We must first of all, express our heartiest gratitude to

respected Mr. Prakash Singh for providing us all guidance to complete project. It would be unfair if

we do not mention the invaluable contribution and timely co-operation extended to us by staff members.

Last but not the least we express our sincere thanks to the UNIVERSAL CABLES LTD. for providing

such a platform for implementing the ideas in our mind.

I would also like to express my gratitude towards my alma mater Jaypee Institute of Information

Technology, Noida for providing an opportunity of summer industrial training.

-Piyush Shukla

DECLARATION

I, Piyush Shukla, here by declare that I have carried out Summer training project at UNIVERSAL CABLES LTD. Satna (M.P.)

I further declare that the above furnished information is factual and correct to the best of my

knowledge and belief.

Date:

Place: Satna ( Piyush Shukla )

DESCRIPTION OF THE ORGANIZATION

Universal Cables Limited (UCL) was established in 1962 by late Shri M.P. Birla, the then

Chairman, with modern plant for manufacture of Paper Insulated Cables. Since then, the

Company has made rapid progress achieving a world class reputation.In the year 1977,

collaborating with M/s. Asea Kabels AB, Sweden (now called ABB Cables), UCL brought

XLPE technology to India. The Company’s other collaborations are with internationally

acclaimed leaders in their respective fields.

UCL is a leader in the Indian Cable Industry with the widest product range. The cable division

has a very wide range of product. It includes Low Voltage, Medium Voltage and Extra High

Voltage XLPE Power Cables upto 500 kV grade, PVC and Rubber Insulated Power Cables upto

11 kV grade, Control and Instrumentation Cables upto 1.1 kV for any number of Cores/Pairs and

speciality Rubber Cables for Trailing/Flexible standards to suit to customer requirements. Its

Cables and Capacitors are known by the Brand Name “UNISTAR”.To meet the growing demand

of Extra High Voltage Cables (220 kV and above), UCL has already ventured into this market

segment. For this UCL has adopted VCV process at its Satna Plant in technical collaboration

with the World Leader in Cable technology, Furukawa Electric Co. Ltd., Japan. The technical

collaboration covers Cable designing, Manufacturing, Laying, Jointing, Testing and Installation.

UCL has also tied-up with Viscas Corporation, Japan (Power Cable Alliance of Furukawa &

Fujikura) for sourcing new generation cable jointing accessories for 220 kV and above.Apart

from manufacturing Electrical Cables for multifarious applications, UCL is having full fledged

EPC Division to execute Turnkey Contracts for various Utilities/Projects.With this, UCL has

now positioned itself as a complete solution provider for EHV Underground Power Cables

Transmission System upto 500 kV, involving designing, manufacturing, laying, jointing and

installation.The 220 kV Cables prototype sample manufactured by UCL has been successfully

Type Tested as a complete cable system at CPRI, Bangalore creating a land mark in itself as this

is the first successful 220 kV cables system Type Test in India. UCL has successfully executed

orders for 220 kV Cables.

The Capacitor Division of the Company, which commenced operation in the year 1967,

manufactures world class All Poly Propylene (APP) Capacitors for AC applications. This ivision

was set up in collaboration with Toshiba, Japan for manufacture of Paper and Power Capacitors.

In 1977, this Division entered into another technical collaboration with General Electric

Company of USA for manufacture of Mixed Dielectric Capacitors and in 1985 for manufacture

of All PP Dielectric Capacitors.

The product range includes Low & High Voltage Capacitors (415 VAC to 220 KVAC),

APFC Panels, Medium Frequency Water Cooled Capacitors for Induction Furnace

Application, Surge Protective Capacitors, Tuned and Detuned Filter Capacitors, DC

Capacitors. This Division also provides services like Automatic PF Correction Systems,

Harmonic Analysis and PF Studies.

DESCRIPTION OF THE WORK

CRITERIA FOR THE SELECTION OF POWER CABLES

The electrical current in a conductor causes a voltage drop and power losses. The temperature

rise in the cable caused by the losses must be kept within certain limits in order not to shorten the

service life of the cable. The temperature limit varies with the type of cable, or more precisely

the type of insulation. The best way to keep the temperature within limits specified for the type

of cable, is to choose the conductor cross-section so that the cable and its surroundings with the

actual continuous load, achieve thermal balance at a temperature below or equal to the

temperature limit recommended. Cable type and size should be selected keeping in view the

following:-

(1) Application. (2) Working voltage; earthed or unearthed neutral system. (3) Load current, load factor, starting duty and frequency. (4) Installation method. (5) The environment in which the cable has to operate. (6) Short circuit current and system protection. (7) Acceptable voltage drop(8) Economies.

How the above factors influence on the choice of cable?

1. Application:The application of the cable determines the basic factors for the choice of cable

type and the rules according to which it must be manufactured. Following are the major factors

for choice of cable type.

- Conductor materials:

No doubt copper is better conductor material owing to its high electrical conductivity and other

electrical/mechanical properties but due to its high cost and scarcity, researches are being carried

out to find other cheaper and abundant metals which may be a close substitute to copper in

electrical application. Aluminium conductors are being used in place of copper conductors for

the past many years and have proved to be quite satisfactory. The lower conductivity of a

Aluminium (61 % of the annealed copper) results in increased dimensions of the cable and

ultimately of conduits and fittings for the same current carrying capacity as that of a copper

conductor cable. Aluminium conductor cables although bigger and somewhat stiffer when lower

number of wires is used for the conductor than the equivalent copper conductor cables, are still

flexible enough to be installed where a copper conductor cable was formerly used. The

advantages of the lighter weight offset the disadvantages of larger sizes for a given capacity. The

use of Aluminium conductor cables should be preferred as far as possible. The use of flexible

copper conductor is recommended where very high degree of flexibility is required as in the case

of mines etc.

- Insulating materials:

The right type of insulation material for a particular usage depends upon the voltage grade,

operating temperature required, degree of flexibility, current capacity requirement and

restrictions on size etc. and other climatic conditions.

- Metallic Sheathing:

Either pure lead or different lead alloys are used for Sheathing of PILC cables and each has

it’s own advantages.The most common and popular alloy is lead Alloy 'E'.

-Bedding and Serving materials: In case of PVC cables the normal bedding and

serving materials are PVC compound. The normal bedding and serving in case of PILC cables

consist of a combination of an impregnated paper, cotton and Hessian tapes and bituminous

compound. These materials provide protection against corrosion of armour and lead and are

suitable in great majority of installations. However, in special cases where severe chemical

corrosion is to be encountered, the use of PVC bedding and PVC serving is recommended.

-Armouring:

The purpose of armour is to provide mechanical protection to the cable and to facilitate earthling

for safety requirements. This also carries phase to ground fault currents of the system

safely.Double steel tape provides good mechanical protection but when in addition

longitudinal stresses are encountered during the installation or in service, steel wire/strip

armouring is recommended for vertical armouring should be preferred. Double wire runs, river

crossing, cables laid on bridges and mine shafts etc. where longitudinal stresses are expected.

2. The system voltage determines the voltage class of the cables.

3. The current rating is, in general, the decisive factors for fixing conductor cross-section. But

in certain applications where intermittent load is required, it is more relevant to use the squared

average r.m.s. current with a reduced cross section.

4. The power cables must be capable of carrying, the required normal full load current

continuously under the site conditions throughout the year. Therefore, the current ratings

specified must be corrected to site conditions by applying suitable derating/uprating factors

depending upon -

(a) Ground or ambient air temperature (max.). (b) Thermal resistivity of soil during dry season. (c) Depth of laying. (d) Total number of cables/circuits in groups.

5. (A) Chemical substances in the environment might cause special stringent requirements on

the outer covering.

(B) If it is necessary to reduce the propagation of fire along cable route combined with low

corrosivity, toxicity and smoke generation characteristics for cables, "FRLS' cables (Flame

Retardant low Smoke) with thermoplastic or thermosetting material or fire survival cables with

elastomeric material should be used. These types of cables are designed with special

composition of protective sheath materials, and by using beat barrier tapes etc. for use in such

critical fire risk installations.

6. Short circuit current together with duration of short circuit determines the short circuit

energy the cable insulation has to with stand thermally.ln certain cases a larger size of cable

then the cable required for normal full load current may be needed to match system short

circuit current levels. Voltage drop is also a major factor in deciding the conductor size of the

cable. The cross section of the cable should be chosen such that voltage drop of the cable for

the given route length does not exceed the statutory requirement.

7. Naturally, the most economical construction and the size of the cable consistent with

required current carrying capacity and laying condition has to be selected. Thus the selection of

particular type of cable i.e. PVC, XLPE, PILC or rubber and the particular material for

screening, sheathing, bedding, armouring or serving etc. out of many choices available depends

upon the usages, laying and climatic conditions. The design of the cable for a particular

application must be optimized taking into account all the above-mentioned factors. In case

expert guidance in this respect is desired, please contact UCI Technical Service Division. UCL

SATNA

Manufacturing Process

The over all stages of manufacturing consists of the following different types of processes.

1) Wire Drawing -Annealing, Tinning, Bunching, Stranding

2) Insulation -Paper/PVC/Rubber/XLPE/Fluroplastic/Polythelene

3) Laying

4) Impregnation

5) Lead Sheathing

6) Bedding – Extruded/wrapped/fibrous lapping

7) Armouring -Round wire/Flat strip/Steel tape

8) Sheathing

The details of above manufacturing processes are as given here under :-

Wire Drawing:

Wires of different sizes are drawn from Aluminium/Copper rods on wire-drawing machines. The

size(diameter) of wire depends upon the over all cross sectional area of the ultimate cable

under manufacture as well as the flexibility requirement. Annealed copper Wires for flexible

rubber cables are then tinned before they are released for next process. The tinning is done by

passing the cleaned cu. wires seated with the flux through molten tin both. The excess of tin

adhering to wire surface is wiped out by means of wipers

Stranding - The Al or Cu. wires or tinned copper wires as the case may be are

bunched/stranded together. The direction of stranding of alternate layers is always kept in

opposite direction in order to have tight and balanced configuration of wires. The standard

Conductor may be compact circular or shaped as per the cable construction.

INSULATION

(1) PVC - Different type of PVC compounds are used for required Physical & electrical

properties and continuous operating temperature of cables. PVC compound extruded over

conductor by extrusion process on different sizes of extruders as per the size of conductor. In

line to extrusion process H.V. testing (Spark testing) is being done to check the quality of

extruded core.

2. Rubber - Natural or synthetic rubber based compounds are prepared to meet the physical &

Elec. properties and continues operating temp. of cable. Various types of rubber compounds are

then extruded over the conductor as per the requirement of the customer.

3. Paper insulation - In this case insulated paper tapes are lapped on conductor. The thickness

of insulation is built up by required number of paper tapes according to voltage grade of cables.

The top layer of paper tapes is suitably numbered for core identification.

4. XLPE – XlPE cables have become very much popular now a day. These cables are replacing

paper-insulated cables right from low voltage grade to extra high voltage grade. In these cables

two types of constructions are used ie screened and unscreened. 11 KV and above grade

cables are all screened. Conductor screen, insulation and insulation screen are generally

applied in one operation called dual-tandem process. M/s Universal Cables Ltd is one of the

pioneer cable manufacturers of XLPE cable up to 132 KV grade cables in INDIA.

Vulcanization/Cross-linking: Rubber and XLPE cables are vulcanized after extrusion. This

process is done just after extrusion on CV/CCV/PLCV lines. This process is done to improve the

electrical and physico-mechanical properties of rubber and polyethylene compounds. In some

cases batch vulcanization is carried out for rubber cables and low voltage XLPE cables.

Laying up of cables.

The insulated cores are laid up along with filling material and twisted to get approximate circular

Cable. A binding tape is also provided to hold the fillers and maintain the circularity of laid up

cables.In case of paper-insulated cables if the cables are belted type, belt insulation is done

along with laying up process by providing required no. of paper tapes and in screened type

cables copper woven fabric tape is provided over laid up cores.

Impregnation process.

Paper insulated cables need a special process known as impregnation. The function of this

process is to extract moisture out of paper insulation and impregnate the insulation with

moisture resistant insulating compound.Heating the Cable under vacuum for some period and

then filling the insulating compound over cable within the impregnating vessel do this process.

The cycle of drying flooding and cooling etc. depends on size and voltage grade of cables. By

impregnation the electrical properties of paper insulation are enhanced. Procedure adopted for

drying and impregnation of paper-insulated cables comprises the following stages.

1. Rewinding the cables in impregnation trays

2. Loading the trays in the impregnation tanks

3. Heating the cables under vacuum

4. Impregnating of cables with impregnation compound for required period

5. Unloading the cable-trays from the tanks after impregnation.

The compound used for impregnation is a petroleum product and has excellent electrical and

mechanical properties.

Lead sheathing

After impregnation, lead sheath is applied over the paper-insulated cables. This process is

done by sleeve extrusion (pipe extrusion). The object of Lead sheathing is to prevent the entry

of moisture in the impregnated cable while maintaining the flexibility of cable.

Inner Sheathing/Bedding

PVC and Rubber insulated cables are provided with inner sheathing over laid up cores as

bedding for armouring. In case on PVC cables inner sheathing may be done by lapping PVC/PE

tapes or by PVC extrusion but in case of rubber insulated cables rubber extrusion is done for

this purpose.

Armouring

The armouring is provided to provide mechanical protection of cables during handling and

installation.Thi is done by providing galv. round steel wires or galvanised steel strips or

double steel tapes over the bedded cables.Though the main function of armouring is to protect

the cable from outside mechanical damages to the cable but it also serves the purpose of carrying

the short circuit current produced during system failure or any type of short circuit in the system.

Sheathing/Serving:-

After armouring or in case of un-armoured cables, the laid and bedded cables are provided with

a protective sheathing of extruded PVC or PE sheath. Paper insulated cables are generally

provided with a fibrous lapped serving but PVC or any other type of extruded sheath can also be

given if required.

Telecomunication Cables: Apart from power and control cables, telephone cables are also

manufactured. These cables are generally called PIJF cables meaning Polyehylene Insulated

Jelly Filled cables. In these cables copper wire of suitable size is insulated with Polyethylene.

Two insulated wires are twisted together to form a pair. Required numbers of such pairs are

grouped together and filled with special moisture resistant jelly. The filled cable is than screened

with polythene laminated aluminium foil and sheathed with LDPE compound. The cable is finally

armoured with galvanized double steel tapes and jacketed with LDPE compound.

Final testing :-

All cables are rewound in proper size wooden/steel reels and sent to testing section where all

the cables are subjected to rigorous electrical and physical tests. Both the ends of cables after

testing are sealed and given a unique identification number. These are then handed over to

marketing department for onward dispatch to relevant customer

Quality control

In universal cables quality is maintained by following a in built quality system which is based on

international specification IS/ISO 9001.

A property organized system of control of quality of product and process is followed for the

efficient production of product acceptable in all respects to the customer. Products are tested

and processes are controlled at all stages of manufactures from raw material to the finished

stage. In addition certain standards procedures are adopted in order to ensure that product

successfully fulfils the customer requirement.

Electrical and Mechanical maintenance:

Electrical and mechanical departments are responsible for the periodic maintenance of all

machines and equipments. A comprehensive schedule of PPM is followed to avoid breakdowns

and thereby loss of machine and men hours. Both these departments are also looking after

break down maintenance and installation &commissioning of new machines and instruments.

These departments also carry out calibration of various electrical and mechanical instruments.

CONCLUSION

Hence in the last I can say that taking training in such an organization proved to be very

beneficial for me. I learnt quite a lot about processes of cable making, selecting of cable material,

and how different processes like bedding, armring, serving are done. In short, i got first hand

knowledge of how cables are made.

The first phase of training has proved to be quite fruitful. It provides an opportunity to encounter

with such huge machines.

The architecture of company has various units. They are linked and working of whole plant is

controlled make the student realized that engineering is not just learning the structure description

and working of various machines. But the greater part is planning proper and management.

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