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INTRODUCTION

KEL is one among the largest, most vibrant, and productive Public Sector Undertaking, and is fully owned by the Government of Kerala. A multi-product engineering company, consistently catering to an envious client base, ranging from the army and air force of India to world-renowned space research organizations, highly competent engineering companies to mammoth institutions likes the Indian Railways. The company with four state-of-the-art manufacturing units spread across Kerala has a pan India presence with marketing offices in major metros and select cities.
Established in 1946 in the State of Kerala, India, the Kerala Electrical & Allied Engineering Co.Ltd. (KEL) is a multifaceted company fully owned by the State government. The location of the industry in the banks water was to facilate easy transportation of goods.
KEL has pioneered this technology in India imbibing the technology from EVR of France in 1977. Subsequently through in house R&D efforts the brushless was soon modified and fully indigenized and customized to suit the tropical climatic condition of India. These brushless alternators have made it possible to improve the quality of passenger comfort by the proliferation of air conditioned coaches in the Indian railways. At KEL innovations continue as an on –going process to deliver specific design of various ratings of brushless alternators as required by the railways. Various type of this brushless type alternator designed and developed in-house include 3.0kw, 4.5kw, 12kw 18kw, and 25kw.The 12kw alternator was specially custom designed by KEL for the use in Janashadabdi express train. The in-house and R&D has also developed and supplied the microcontroller based electronic rectifier regulator unit (ERRU) for use in 4.5KW and 25KW brushless alternator. The absence of moving sliding contacts and slip rings ensures a maintenance free long life for the alternators.

TOWARDS POWER GENERATIONThe outstanding product of the division is the statodyne brushless alternators for lightening and air-conditioning of rail coaches and manufactured under license from EVR France rating 1KW to 14KW.

STATODYNE BRUSHLESS ALTERNATOR
A homopolar machine of simple design and robust construction conforms to international standards. With no slip rings, no brushes no rotating windings no moving parts carrying current, the alternator is a revolutionary product in the power generation concept.


 Testing and Quality control
FOUNDRY DIVISION
KEL has a modern cast iron foundry with capacity of 1500 MTs/annum; manufacturing speriodical graphite iron and gray iron casting of various grades. A foundry is a place where the casting is produced. Casting is a mechanical process for producing required components. Through all metals can be cast, cast iron is more widely used for casting. This is because of its fluidity, small shrinkage and case with which its properties can be controlled. Principle of casting consists of introducing molten metal into a cavity or mould of desired shape and allowing it to solidify. Cavities are formed by using patterns and cores of required shape. The casting material of foundry at KEL is cast iron of different grades 15,20, 25 etc. About 50% of the production here includes various parts and accessories of the brushless alternator. Other major products include end brackets for diesel generators sets, break block for railways etc in cast iron and inserts for railways in SG iron etc. A well equipped laboratory with sophisticated materials ensures production of quality casting.
MACHINE SHOP
It is a place where various machining process are carried out as required. There are two machine shops in this unit- new machine shop and old machine shop. The different machines used are lathe, drilling machine, milling machine, grinding machine, pressers, shapers etc. The section deals with the following production processes:
• Insertion of stator stampings in to fabricated outer frame
• Assembly of rotor
• Fabrication of pulleys

These processes are explained in detail
STATOR FRAME
Based on the shelf number, the stator diameter is fixed. the inner diameter corrected to accommodate the windings. Consider a 25 KW alternator. The unite obtained from fabrication is of 249 mm diameter, which is corrected to 255 mm only 52 micron variation is permitted.
After this, it goes to stacking and pressing equipment. Here silicon steel laminations are stacked on one another as shown in diagram. Fiber laminations are fixed on to the circular clips to prevent loss of insulation. This is then compressed under a pressure of 6 kg/cm to press it. A guiding ring is used to prevent twisting.
Thus the following processes are carried out on the stator frame:
• Boring
• Drilling
• Slotting
• Stacking of Laminations
• Filling
The stator frame is now passed on to the winding section

WINDING AND ASSEMBLY UNITThe most important step in the fabrication of alternator is the winding of the field and phase coils.
Assembly
Assembly consists of the alternator can be processed on the reverse way with special care on the following points.
 The inner race of the bearing should be heated in an oil bath at about 80-90 degree before insertion on to the shaft.
 The end shield should be heated in an electric oven to about 120 degree Celsius before locating the bearing in it. The bearing should not be pressed with hydraulic press.
 In order to seat the bearing properly, internal bearing cover should be fixed onto the end shield before heating the eng shield.
 Assembly of pulley should be made with extreme case. See that the pulley bore males exactly with tapered shaft.
 Gasket shellac is applied evenly on all the mating surface of bearing cover and end shield.
 While removing and fixing 5KF lock nuts use a hook spanner. Never use any other tool for this purpose.
 Lock washer should be replaced by a new one.
REGULATOR AND RECTIFIER UNITBecause the voltage induced in the alternator depends on the speed of the rotor, the output of the alternator is obtained through the regulator rectifier unit. Regulator unit regulates the voltage and rectifier unit converts the AC voltage to DC and stores in its batteries.