Repairing of defective Stator RADE KONCOR, of 40 MW Generator by carrying out refurbishment or replacement of stator core and complete re-winding of stator with new class F insulated VPI stator bars at Kodayar Power House

Amount

Charges towards de- brazing all the end connection jumpers both phase and neutral bus bar with suitable thermal protection

Charges towards removing the 152 Nos top and 152 Nos bottom end insulations and End cap

Charges towards De- brazing 152 Nos. non- connection side (Bottom side) end ferrules with suitable thermal protection

De- brazing 152 nos. connection side (Top side) end ferrules with suitable thermal protection

Charges towards removing of wedges from 152 Nos.slot using suitable tools without damaging the coil conductor and core.

Charges towards removing the 152 Nos top coils and 191 Nos bottom coils special jigs and fixtures without damaging the coil conductor and core.

Charges towards conducting the ELCID and 100% Flux loop test to ascertain the integrity of insulation of stator core and find out the hot spot if any required equipments & cables to be brought by vendor

Charges towards cleaning and polishing the stator core pack slot for ready to install new/ re-insulated coils.

Charges towards supply of new transposed class F stator coil (top or bottom) as per the existing bar.

Charges towards conducting test in the new supplied bars.

Charges towards replacement of all the winding temperature RTDs.

Charges towards procurement of the required quantity of glass epoxy class “F” liners, wedges and dying card, mouth block coil overhang support epoxy spacer tape and resin etc., for completing the repair works in good manner.

Charges towards transporting the new coils from contractor works to Power House using suitable fixtures.

Charges towards re-insulating both top and bottom side overhang surge ring -4 nos. in the stator assembly with class ‘F’ insulation.

Charges for removing the insulation of 6 Nos bus bar and 6 Nos jumpers and re-insulating with class ‘F’ insulation, re-fixing with new blocks and banding.

Charges towards installing 234 Nos Bottom bars and 234 Nos Top bars using fresh liners, wedges and end binding the overhang portion with fiber tapes and cards using the binding cement of epoxy resin.

Charges towards brazing both ends of 234 Nos. top bars with respect to 234 Nos. bottom bars, jumpers using 15% silver brazing material and insulating the brazed overhang portion with class “F” insulation resin and testing.

Charges towards drying out stator winding and checking the IR & PI values at two hours interval to ascertain the dryness of the stator.

Charges towards conducting the following tests after completion of stator winding. i) IR value at 5 KV before and after HVAC test. ii) AC High voltage test at 23 KV, 50Hz for 1 minute. iii) PI value iv) Winding resistance v) Tan delta test at 11 KV in steps of 0.2, 0.4, 0.6, 0.8 and 1.0 VL.

Supply of spare new Bottom & Top Coil (Each 25 Nos.)

Option: Dismantling the entire core, handing over the old stampings to TANGEDCO Stores, procuring the raw materials for making 100% new laminations, making a punching tool, punching the stampings, removing the burrs, re-varnishing and conducting following tests on the sample. a. Xylol Test b. Mandrel Test c. 7H Pencil Hardness Test d. Insulation Resistance Test by applying 110 V AC between 10 Nos. stampings clamped together with a lamp series. The lamp should not glow. Transporting the core to the site, stacking and locking the core.

Description of Work / Item(s)

Amount

Charges towards de- brazing all the end connection jumpers both phase and neutral bus bar with suitable thermal protection

Charges towards removing the 152 Nos top and 152 Nos bottom end insulations and End cap

Charges towards De- brazing 152 Nos. non- connection side (Bottom side) end ferrules with suitable thermal protection

De- brazing 152 nos. connection side (Top side) end ferrules with suitable thermal protection

Charges towards removing of wedges from 152 Nos.slot using suitable tools without damaging the coil conductor and core.

Charges towards removing the 152 Nos top coils and 191 Nos bottom coils special jigs and fixtures without damaging the coil conductor and core.

Dismantling the entire core, chemical washing, drying in the conveyor oven at 180°C mounted at site, varnishing the core with F class insulation in rubberized roller to maintain the uniform thickness, drying out the core at 200°C, once more re-varnishing and drying, checking the IR value of the core, assembling the core, re- staggering and restacking, maintain the core back thickness, locking the core by insulating core bolts and checking the IR value of core bolts. The following tests are to be carried out in the re-varnished core before staggering .a. Xylol Test b. Mandrel Test c. 7H Pencil Hardness Test d. Insulation Resistance Test by applying 110 V AC between 10 Nos. stampings clamped together with a lamp series. The lamp should not glow

Charges towards conducting the ELCID and 100% Flux loop test to ascertain the integrity of insulation of stator core and find out the hot spot if any required equipments & cables to be brought by vendor

Charges towards cleaning and polishing the stator core pack slot for ready to install new/ re-insulated coils.

Charges towards supply of new transposed class F stator coil (top or bottom) as per the existing bar.

Charges towards conducting test in the new supplied bars.

Charges towards replacement of all the winding temperature RTDs.

Charges towards procurement of the required quantity of glass epoxy class “F” liners, wedges and dying card, mouth block coil overhang support epoxy spacer tape and resin etc., for completing the repair works in good manner.

Charges towards transporting the new coils from contractor works to Power House using suitable fixtures.

Charges towards re-insulating both top and bottom side overhang surge ring -4 nos. in the stator assembly with class ‘F’ insulation.

Charges for removing the insulation of 6 Nos bus bar and 6 Nos jumpers and re-insulating with class ‘F’ insulation, re-fixing with new blocks and banding.

Charges towards installing 234 Nos Bottom bars and 234 Nos Top bars using fresh liners, wedges and end binding the overhang portion with fiber tapes and cards using the binding cement of epoxy resin.

Charges towards brazing both ends of 234 Nos. top bars with respect to 234 Nos. bottom bars, jumpers using 15% silver brazing material and insulating the brazed overhang portion with class “F” insulation resin and testing.

Charges towards drying out stator winding and checking the IR & PI values at two hours interval to ascertain the dryness of the stator.

Charges towards conducting the following tests after completion of stator winding. i) IR value at 5 KV before and after HVAC test. ii) AC High voltage test at 23 KV, 50Hz for 1 minute. iii) PI value iv) Winding resistance v) Tan delta test at 11 KV in steps of 0.2, 0.4, 0.6, 0.8 and 1.0 VL.

Supply of spare new Bottom & Top Coil (Each 25 Nos.)