Rewinding of Unit#6 Generator at Sabarigiri HEP

Part A- Supply. Supply of winding and Other materials

Charges towards manufacture and supply of 200 Nos. new class ‘F’ insulated VPI stator coils which includes 20 Nos. spare coils.(Out of 200 coils 15 should be half insulated open coils) The following tests should be carried out during manufacturing process. i) Dimensional check ii) Coil Resistance Measurement iii) Inter strand IR value test at 110 V AC for 3 sec as ESI Standard 44-7, June 1978 iv) Inter turn insulation test as per IEEE 522:2004 using HVHF test set v) IR value at 5 KV before and after HVAC test for 1 minute vi) HVAC test at 26 KV for 1 minute as per BS 4999: Part 60:1976 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 IEEE Std 1310

Charges towards packing the spare 20 Nos. coils in a vacuum packing with wooden boxes

Charges towards supply of complete winding kit for stator winding like wedges, packing under the wedges, mouth blocks, insulating tapes, varnish, slot side and bottom side packing, separators and brazing rods.

Charges towards supply of complete winding kit for 20 nos. spare stator winding like wedges, packing under the wedges, mouth blocks, insulating tapes, varnish, slot side and bottom side packing, separators and brazing rods.

Charges towards supply of PT 100 RTD’s for temperature measurements.

Description of Work / Item(s)

Part B- Labour. - Work for Dismantling ,Erection,testing and Commissioning of Winding

Charges towards fixing the special rotating device (Fabricated by vendor) on the shaft and measuring the run out readings at 4 positions (0, 900, 1800 & 2700) by fixing set of dial gauges at quadrature positions (0 & 900) in thrust collar, UGB and turbine guide bearing housing by rotating manually, jacking the rotor, applying special grease if required between therunner disc and thrust pads and record for each reading.

Charges towards decoupling, dismantling the slip ring chamber, upper and lower bracket and bearing assembly and their related components and treading out the rotor and placing in the rotor pit

Charges towards de brazing, de-wedging, removal of end banding and removal of old coils and handing over the old removed coils to Department as it is where it is condition

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

Charges towards re-insulating the stator overhang surge ring with class ‘F’ insulation.

Charges towards reinsulating existing main Bus bar with class F insulation

(Optional)- If the ELCID test reveals hot spot, charges towards dismantling the entire core , chemical washing, drying in the conveyor oven @180℃ mounted at site, varnishing the core with F-class insulation in rubberized roller to maintain the uniform thickness, dryinh 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. i. Xylol Test – as per IS 648:2006 – 7.2.8 j. Mandrel Test – as per ASTM-D522 k. 7H pencil Hardness Test – as per IS101 (part-5 sec-1) – 1998 Class 4 l. Insulation Resistance Test by applying 110V AC between 10 Nos. stampings clamped together with a lamp series. The lamp should not glow As per ESI standard 44-7 June 1978

Charges towards rewinding the stator and testing. Test after installing the stator coils in the slots and wedging before connection i) IR value at 5 KV before HV AC test ii) HV AC test at 25 KV iii) IR value at 5 KV after HV AC test Final test of stator i) DC resistance measurement ii) IR value at 5 KV before HV AC test iii) PI value at 5 KV iv) HVAC test at 23 KV as per IS 4722:1992 v) IR value at 5 KV after HV AC test vi) Tan delta test at 2 KV, 4 KV & 6.3 KV as per ESI Std 44-7, June 1978 and IEEE Std 286-2000 vii) Partial Discharge Test as per IEEE Std 1434

Charges towards cleaning, testing and varnishing the rotor. The following tests will be carried out i) DC resistance measurement ii) IR value at 2.5 KV before HVAC test iii) HVAC test 2.5 KV iv) IR value at 2.5 KV after HVAC test v) AC pole drop test vi) Impedance measurement test

Charges towards coupling of rotor and turbine

Charges towards assembling the Generator and aligning

Charges towards in-situ balancing the rotor

Charges towards drying out, final testing and commissioning the Generator including successful trial run(72 hours) of generator.Final testing includes the following HV AC Test as per relevant IS IR test before and after HV AC Test Tan Delta test Winding resistance Test Surge comparison test Partial discharge test

Description of Work / Item(s)

Total - Supply and Labour

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

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