Repair, rewinding and overhauling of Shinko make 350kW, 3.3kV, 4 Pole, Induction Motor of Cold Well Pump, Phosphoric Acid Plant, FACT-CD, Ambalamedu.

Repair, rewinding and overhauling of Shinko make 350kW, 3.3kV, 4 Pole, Induction Motor of Cold Well Pump, Phosphoric Acid Plant, FACT-CD, Ambalamedu.

Motor dismantling and flux loop testing: The work includes removing cooling fan cover and fan, radiator, dismantling the motor, threading out the rotor from the stator core pack, inspection of stator/rotor/end overs/bearing cup assembling parts, stripping out of old stator windings, cleaning the stator slots, conducting flux loop tests on stator and rotor to find out the core damages.

Stator core restacking: The work includes mounting the stator body in hydraulic press, removing the core pack from stator body with special tools and machineries after heating the stator yoke with special heating arrangements, segregating the damaged stator core from core pack, removing the old burnt core plate varnishes by chemical treatment, cleaning, removing the surface kinks, replacing damaged core stampings with new one, varnishing the stampings in re-varnishing cum conveyor oven to cure the core plate varnish, staggering the core with special tools and machineries, locking and repositioning the core pack to the stator body by hydraulic press and finally conducting the flux loop test to ascertain the restacked core healthiness, cleaning and polishing the slots ready to feeding. Insulating and anti-corrosive coating shall be applied on slots, after cleaning. This work shall be executed after analysing the stator flux loop test report, visual inspection and after getting approval from concerned engineer in charge. If partial re-staggering only required, the payment will be done proportionally.

Stator rewinding (3.3KV): The work includes rewinding the stator using of class `F’ enamelled double fibre glass covered electrolytic grade new copper conductors for rewinding coils as per the original shape and dimension by using special jigs and dies, insulating the slot portions using semicatherm insulating materials, moulding the slot portion in hydraulic hot press, applying flexible insulation to the overhang portion, inserting the coils in to the slots, banding the overhang portions in the surge ring, fixing new bush insulator and Brass stud/washers/nut for termination, bracing, tinning, soldering, forming the end connection, preheating, doing vacuum pressure impregnation(VPI), curing, fixing heater coils and heater covers, wiring heater coils to the terminal block, applying finishing varnishes. Good quality, glass laminated (or superior) wedges shall be placed over the coils in slots. Suitable spacer (filler material) shall be inserted between coils at the overhang portion, to avoid vibration of individual coils. The contractor shall arrange new Bush insulator, Brass stud/washers/nut, 230V/250W heater coil and cover, thermal insulated wires for successful completion of the work. The brass nut shall have large contact area for terminating 225 sq.mm Aluminium cable lug.

Works on motor rotor. The scope of work includes machining and polishing rotor, dipping the rotor in varnish and baking, metalling & machining bearing housing and end covers seating area of rotor, inserting sleeves/machining of rotor shaft for dimension correction, suiting bearings, end covers, bearing housing, inner grease cups and outer grease cups in the rotor.

Motor radiator cooling tube repair works. This work includes replacing of damaged cooling tubes, cleaning, painting and testing. This work shall be executed on the basis of requirement and after getting approval from concerned engineer in charge. If partial repair work only required, the payment will be done proportionally.

Die casting & machining of new bearing housing, inner & outer collars, bearing grease cups, end plates/ washers, replacement of oil seal, etc., in the drive end of the motor and make it similar and suitable to match with the original shape and size of the bearing compartment of the motor.

Rotor balancing: The work includes Fixing of inside cooling fan on rotor using new nut/bolt/star washer/spring washer, inserting outer cooling fan/coupling and doing dynamic balancing of rotor to balance quality grade of G2.5 at rated RPM. Anabond thread sealing compound shall be applied to the thread of bolts to avoid loosening due to vibration. This work shall be done after rotor repair work.

Assembling, painting and testing of motor: The work includes assembling of motor using the new bearings supplied by FACT (free of cost), properly fixing the cable terminal boxes, painting of motor using two coats of anti-corrosive epoxy paint over suitable primer, conducting routine tests as per relevant IS standers and No-load trial run at the rated voltage of 3.3 KV. All test reports shall be submitted before dispatching the motor. The test results shall be in compliance with applicable standards/ regulations etc. In case of deviations beyond acceptable values, they shall be brought to normal values by carrying out necessary corrective measures without any extra cost to FACT. Mobil Unirex N3 grease shall be used for motor bearing lubrication.

Delta Roto tech Pvt. Ltd. (BID ID -3141546)

GENLINE ELECTRIC (BID ID -3136101)

RAJAMANE AND HEGDE SERVICES PVT LTD (BID ID -3144575)

INDIA ELECTRIC WORKS (BID ID -3145055)