Replacement of Stator Core and Winding of Unit 1 of Kallada HEP

Part A- Supply of Stator Core ,copper coils as per sample ,insulating and binding materials and Accessories for the complete replacement of the existing core of 7.5 MW, 11 kV, 3 Ф alternator

Supply of Stator Core-The stampings shall be cut from low loss non grain oriented sheets (CRNGOSS)50C270 grade sheet with C3 coating or better as per IS 648/2006. The stampings should be suitable for replacing the existing core and for perfect fitment in the existing stator frame which will not be replaced. The accessories shall include all the items like Ventilation spacer plates, Core tightening studs, Pressing plate tightening bolts etc as required in complete for proper installation of the core.

Supply of 170 (150 +20 spare coils) numbers of coils formed from copper strips and insulated with class ‘F’ insulation materials suitable to replace the existing winding and to suit the core

Supply of insulating and binding materials required for replacing the complete existing winding such as wedges, packing under wedges, mouth of slot packing blocks, insulating tapes, varnish, slot side and bottom side packing, separators, end winding packing blocks, coil joining accessories such as bracing rods, acetylene gas, 12 Nos. RTDs for temperature measurement etc as required in complete for the replacement of the complete winding.

Description of Work / Item(s)

PartB LABOUR

Dismantling the Oil Header, Oil pipes through the shaft, Feed Back wire ropes, Casing, Brush Gear, Collector Ring, PMG, Over Speed Device, Oil Vapour Seal, Floor Plates and Supports, Air Guides, D C Connections, Cables, Top and Bottom Bearings, Thrust bearing, Oil and Water pipes, Thrust Collar, Upper Bracket and support the Runner and Runner Shaft on suitable supports and uncouple the Generator Shaft from the Runner Shaft and lift the Rotor after noting down the existing data regarding alignment etc.

Dismantling the existing stator winding, interconnections and bus bar connections from the core and handing over of all the materials to KSEB.

Dismantling stator stampings, core bolts etc. from the stator frame and handing over of all the materials to KSEB.

Stacking the new core laminations, pressing, tightening the core studs and all the allied works in connection with the building of stator core including the installation of RTDs for temperature measurement.

Conducting ELCID test on the core to ensure healthiness of the Core.

Conducting HV testing of the newly supplied individual coils, installation of 150 nos. of stator coils and the RTDs including binding with suitable packers, insulating blocks, bracing the end connections, making the interconnections and bus bar connections, insulating etc and drying-out of winding and conducting HV test on the complete winding as per direction of KSEB Engineers.

Re assembly of the Generator Rotor and all dismantled items vide Sl.No. 1

Levelling and aligning rotor and coupling turbine and generator shafts, checking & correcting unit axis alignment, centering the rotor w.r.t turbine runner blade tip clearances with runner envelope and check generator rotor to stator air gap and magnetic axis centering. Record the readings.

Lock shaft at UGB and set bearing clearances and box up all bearings.

Install shaft seal of turbine and box up turbine.

Final testing and commissioning of the generator including final balancing of rotor for safe vibration as per IE standarad IS 7919-5& is 14817-5 at UGB,LGB& TGB.

Description of Work / Item(s)

Part C

Part A- Supply :ie. Total of BoQ1

Part B- Labour :ie. Total of BoQ2