REPAIR/MAINTENANCE OF HT/LT FREQUENCY CONVERTERS, RECTIFIERS ETC AT NAVAL DOCKYARD MUMBAI UNDER GE (NW) KUNJALI, COLABA, MUMBAI

Amount

M&L for decoupling of motor and generator at site by disconnecting incoming and outgoing cable of capacity 860 KW, 600 RPM, 6.6 KV set. The work involves removal of pedestal bearing machines including shims ie thin liners of sheet metals of various thickness under pedestal bearing and the feet of the stator frames. Proper diagrams and marking on the shims should be recorded as a guide. Levelling must be carried out very accurately, as the success of full operation of the machine depending largely on the correct installation of the bearing/machine complete all as specified and directed. Note for item No 1 to 24.00: The work will be carried out by authorised agency/ OEM

M&L for shifting of motor and generator of capacity 860 KW, 6.6 KV set from dockyard to workshop within 100 km on heavy duty loader for complete overhauling of FC set complete all as specified and directed by Engr-in-Charge. Note: The cost of crane/ lifting hoist and transportation shall deemed to be included in the rate quoted

M & L for dismantling of motor and generator and excitor stator rotor for repairing/ overhauling. Removal of the bearing pedestal from its position after putting the necessary shims. Removal of the upper half of the bearing, the rotor will be supported by the crane hook on the coupling side till the nuts are loosened carefully removal of the oil rings, the rotor will be carefully removed. Proper cleaning of the pedestal bearing oil well before reinstallation and lower half of the bearing should be cleaned properly, The bearing will be placed in position and coated with oil complete all as specified. Notes: (i) During working on stator frames comprising of the following: The appropriate shims in the feet of the stator frames will be placed in position, dismantling/reinstalled of stator frames installed from the base plate as per record/drawings. Placing of board packing in the air gap between rotor and stator in order to avoid damages to them while transportation. (ii) During working on dowel pins and comprising of the following: While reinstallation of machines on site it will be ensured that the existing dowel holes in the stator frames and bearing pedestal to the base plate will be in the correct position and alignment.It will be ensured that all dowel holes are in one line for correct alignment of the parts. (iii) During working on bearing and rotor which comprises of the following: To prevent the damage of the bearing insulating shims under the pedestal will be provided to avoid damages due to shaft currents. The insulating shims will be placed next to steel shims. The FC should be provided with insulating holding down steel bolts of appropriate size.

M&L for overhauling of 860 KW, 600 RPM, 6.6 KV FC set by the authorised dealer/OEM as per the following maintanance schedule:- (i) Checking all fans/blowers for proper working/functioning. (ii) Checking all the door locks/interlocking system for proper functioning. (iii) Checking all the indication lamps/lights working or not. (iv) Checking the emergency stop switched. (v) Checking any abnormal sound/noise from the rectifier. (vi) Cleaning of the equipment and associated switchgear. (vii) Checking all the sensors. (viii) Clean the equipment carry out dust cleaning with blower. (ix) Checking ACB/MCCB contactors and tight. (x) Checking and cleaning all the contacts with CTC for proper working/functioning. (xi) Checking voltage and current potentiometer for proper working. (xii) Checking all the bus bar fittings. (xiii) Checking and tighten the rectifier bridge fittings. (xiv) Checking built in meter, SPP, OL system etc. (xv) calibration of the meters. All electrical meter are to be calibrated by authorised agency and certificate to be produce to user. (xvi) All safety equipment to be calibrated and tested for its satisfactory functioning.

M&L for following static test of winding using special tools test jigs as per manufacturer recommendation: (i) Insulation resistance of winding (ii) Winding resistance (iii) Surge comparision test (iv) Polarization index test etc

M&L for conducting of following test on all winding of motor generator, exciter stator and rotor of 860 KW FC Set, 6.6KV, 600RPM, complete all as specified and directed by Engr-in-Charge. (i) Dry ice (CO2) cleaning of winding of FC motor generator, exciter stator and rotor. (ii) Pre-heating of windings in oven of FC motor generator, exciter stator and rotor. (iii) Varnishing of all windings of FC motor generator, exciter, stator and rotor . (iv) Curing of winding in oven of FC motor generator, exciter, stator, stator and rotor,

M&L for dynamic balancing of generator rotor, synchronous motor rotor and exciter rotor, record of reading on all sides of rotor for proper alignment complete all as specified and directed by Engr-in-Charge.

M&L for white metal relining of 01 Nos pedestal type journal sleeve bearing with spherical seating of size dia 152.4 mm x 228.6 mm length. The thickness of white liner is 3.1 mm complete all as specified and directed by Engr-in-Charge.The white lining process for bearing is a meticulous procedure that involves preparation tin plating, melting and pouring the white metal, cooling machining and thorough inspection. The composition of white metal alloy is critical and varies depanding on the application with tin based. It ensuring the longevity and efficiency of the bearing by providing low friction surface.

M&L for repair of slip ring for generator and motor of current rating 230 Amps made out of mild steel shrunk on to an epoxy glass insulated steel sleeve which is pressed on to the shaft. The brush gear is fixed to the adjuscent bearing pedestral. The bushes are held in contact with the slip ring under adjustable spring pressure suitable for FC 860KW, 600RPM, 6.6KV as per the existing gauge and size including cutting of helical grooves on the surface of sliprings complete all as specified and directed by Engr-in-Charge.

M&L for Re-assembly of motor generator & exciter unit of FC convertor 6.6KV, complete all as specified and directed by Engr-in-Charge. Note: (i) During assembling the machines, the air gap must be checked very carefully for eccentricity which should not be more than 5% of the avarage air gap. (ii) The frame should be effectively earthed by a connection of substantial cross section which should be mechanically and electrically sound. (iii) A careful inspection of the machine should be made before first running up. The connection should be tallied with the connection diagram supplied with each machine and all electrical connection tightened firmly. Checking of all clearance between live parts and earth. The bearing should be filled with oil to the correct level and oil ring should revolve freely when the machine is running. (iv) The pedestal bearing oil well should be cleaned before reinstallation and lower half of the bearing should be cleaned, placed in position. The oil ring should be put in position and the top halves of the bearing liner should be oiled and assembled after checking that the oil rings revolve freely, inserting the coupling bolts into the half couplings and tightening the coupling side till the nuts are tightened.

M&L for painting of complete set with spray paint primer and two coat of synthetic enamelled paint not less than 75 to 125 microns as per direction of user/engr-in-charge, complete all as specified and directed.

M&L for shifting of motor and generator of capacity 860KW, 6.6KV set from workshop to Dockyard within 100 km on heavy duty loader after complete overhauling of FC set complete all as specified and directed by Engr-in-Charge. Note: The cost of crane/ lifting hoist and transportation shall deemed to be included in the rate quoted

M&L for unloading of FC set from loader and shifting to its existing position with help of heavy duty hydra/crane safely and installation of motor and generator and exciter with bearings,complete all as specified and directed.

M&L for replacement of lubricant oil servo primer 17 as per BIS-489 for bearings, complete all as specified and directed.

M&L for complete testing of FC with full load with full satisfaction of engr-in-charge/user including measurement of bearing tempreture, vibrations, checking oil leakages from bearings etc. A careful inspection of the working machine will be made before first running up. The connection should be tallied with the original connection recorded. Checking of all clearance between live parts and earth etc complete all as specified and directed.

M&L for taking out of unserviceable VFD of 1250 KVA frequency convertor panel and supply, fixing and testing of new Variable frequency drive, 3 Ph suitable for 1250 KVA FC and testing on full load with full satisfaction of engr-in-charge/user.

M&L for taking out of unserviceable VFD of 750 KVA frequency convertor panel and supply fixing and testing of new Variable frequency drive, 3 Ph suitable for 750 KVA FC and testing on full load with full satisfaction of engr-in-charge/user.

M&L for overhauling, repairing of FC 1250 KVA set control panel by servicing of all parts and replacement of all unserviceable parts like unserviceable digital voltmeter, ammeter , push button, emergency push botton etc and testing with full satisfaction of engr-in-charge/user.

M&L for overhauling, repairing of FC 860 KVA set control panel by servicing of all parts and replacement of all unserviceable parts loke unserviceable digital voltmeter, ammeter , push button, emergency push botton etc and testing with full satisfaction of engr-in-charge/user.

M&L for overhauling, repairing of FC 750 KVA set control panel by servicing of all parts and replacement of all unserviceable parts loke unserviceable digital voltmeter, ammeter , push button, emergency push botton etc and testing with full satisfaction of engr-in-charge/user.

M&L for replacement of unserviceable carbon brush of size 25.4x38x50 mm suitable for 60 Hz frequency convertor HS Code 8545 installed at MSS and testing with full satisfaction of engr-in-charge/user complete all as specified and directed.

M&L for replacement of unserviceable multifunction meter with RS Port EM 6430 fixed in panel complete all as specified and directed.

M&L for replacement of unserviceable bearing pattern No 620422/C or techno commercial equivalent complete all as specified and directed.

M&L for replacement of unserviceable bearing pedestal type journal sleeve bearing with spherical seating dia 152.4mmx228.60 mm suitable for frequency convertor 860/750/1250 KVA complete all as specified and directed.

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