Revival of Stator of Unit No 2 at SGHEP

Part A- Supply.

Design, manufacture and supply of 180Nos.new class ‘F’ insulated VPI diamond type coils with existing coil dimensions and profile in all respect suitable for 55MW (with 10% COL at 0.9PF) loading capability. The following tests shall be carried out during the manufacturing process. i) Dimensional check ii) Coil Resistance Measurement iii) Inter strand IR value test at110VAC for 3sec as ESI Standard 44-7, June 1978 iv) Inter-turn insulation test as per IEEE522:2004 using HVHF test set v) IR value at 5KV before and after HV AC test for1minute vi) HV AC test at 27 kVfor1minute as per BS4999: Part60:1976 vii) Tan delta test at 2.2 KV, 4.4 KV, 6.6 KV, 8.8 kV and 11 KV as per ESI Std 44-7, June 1978 and IEEE Std 286-2000 viii) Partial Discharge Test as per IEEE Std 1434 ix) Voltage Endurance Test on a random sample as per IEEE Std 1043 x) Thermal Cycling Test on a random sample as per IEEEStd1310

Supply of spare 20Nos new Class-F insulated VPI diamond-type coils with dimensions and profile as mentioned in item 1.01

Packing the spare 20Nos. coils in standard packing with wooden boxes

Transporting the 180 Nos new VPI Insulated coils + 20 Nos. Spare VPI Insulated coils from contractor works to Power House using suitable transporting stand-200 coils

Supply complete winding kit (Class-F) for stator winding like insulation materials, wedges, packing under the wedges, mouth blocks, insulating tapes, varnish, slot side and bottom side packing, separators and brazing rods

Supply of complete winding kit (Class-F) for 20nos. Spare stator winding like insulation materials, wedges, packing under the wedges, mouth blocks, insulating tapes, varnish, slot side and bottom side packing, separators and brazing rods.

Supply and installation of PT-100 RTDs for temperature measurements @stator winding and core. (12+12).

Description of Work / Item(s)

Part B- Labour.

Debrazing, de-wedging, removal of end banding and removal of old 180 Nos. Coils and handing over the old removed coils and transporting the removed coils to the store as per the direction of departmental officers.

Re-insulation, refixing and testing the existing stator overhang surge rings with class ‘F’ insulation.

Re-insulating refixing and testing refixing and testing existing main busbar with class ‘F’ insulation.

Dismantling the entire core, chemical washing, drying @180℃, varnishing the core with F-class insulation of superior grade (Subject to approval from KSEB Ltd) by maintaining uniform thickness, drying out the core@200℃, once more re-varnishing and drying, checking the IR value of the core, assembling the core, re-staggering & re-stacking, maintaining the core pack thickness, locking the core by insulating core bolts & checking the IR value of core bolts. The following tests are carried out in the re-varnished core before staggering. a. Xylol Test–as per IS648:2006–7.2.8 b. Mandrel Test–as per ASTM-D522 c. 7H pencil Hardness Test–as per IS101 (part-5 sec-1) –1998Class4 d. Insulation Resistance Test by applying 110 V AC between 10 Nos. Stampings clamped together with a lamp series. The lamp should not glow. As per ESI standard 44-7 June 1978

Conducting ELCID test on the core to ascertain the healthiness of the core during core re-lamination and restacking work.

Conducting flux loop test on the core to ensure the healthiness of the core after restacking before rewinding

Rewinding the stator is complete as per the existing design and testing. Test after installing the stator coils in the slots and wedging before connection i) IR value at 5kV before HV AC test ii) HV AC test at 25KV iii) IR value at 5kV after HV AC test The final test of the stator i) DC resistance measurement ii) IR value at 5kV before HV AC test iii) PI value at 5kV iv) HV AC test at 23kV as per IS4722:1992 v) IR value at 5kV after HV AC test vi) Tan delta test at 2kV, 4kV& 6.3kV as per ESI Std 44- 7 June 1978 and IEEE Std 286-2000 vii) Partial Discharge Test as per IEEE Std1434 viii) Electronic stator wedge tightness detection test shall be used for wedge mapping ix) Testing brazing healthiness using an ultrasonic inspection tool

Drying out, final testing and commissioning the Generator, including a successful trial run (72 hours) of the generator. Final testing includes the following. i.) HVAC test as per relevant IS ii.) IR& PI Tests. (IR test before and after HVAC test) iii.) Tan Delta test. iv.) Winding resistance test. v.) Surge comparison test. vi.) Partial discharge test.

Performance tests to be conducted by reputed agencies to find overall efficiency of the generating unit

Description of Work / Item(s)

Total

Total of BoQ 1 i.e. Part A - Supply

Total of BoQ 2 i.e. Part B - Labour

Voith Hydro Private Limited (BID ID -2199947)

Coral Rewinding India Private Limited (BID ID -2185441)

Voith Hydro Private Limited (BID ID -2199947)