Design, Supply, complete rewinding, supervision, testing and commissioning of VPI insulated stator winding, replacing pole coil leads with new design, replacement of stator core of 60MW Wave wound Generator Unit No.3 at Lower Periyar HEP

Part A- Supply.

Design, manufacture and supply of 600 Nos. (270 Nos actual top bars + 270 Nos. actual Bottom bars + 30 Nos. Spare top bar + 30 Nos. Bottom spare bars) new class ‘F’ insulated VPI stator half bar. The following tests should be carried out during the 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. IR value at 5 KV before and after HVAC test for 1 minute v. HVAC test at 26 KV for 1 minute as per BS 4999:Part 60:1976 vi. Tan delta test at 2.2KV,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 vii. Partial Discharge Test as per IEEE Std 1434 viii. Voltage Endurance Test on a random sample as per IEEE Std 1043 ix. Thermal Cycling Test on a random sample as per IEEE Std 1310

Vacuum packing in wooden boxes for the spare 60 Nos. bars

Supply of complete winding kit for entire stator winding like 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 for 30 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

Supply of PT 100 RTD’s for temperature measurements as required (Minimum 20 Nos)

Description of Work / Item(s)

Part B- Labour.

Fixing the special rotating device (Fabricated by contractor) 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 the runner disc and thrust pads and record for each reading.

Decoupling, dismantling the slip ring chamber, upper and lower bracket and bearing assembly and their related components (For decoupling hydraulic jack will be supplied by KSEBL) and threading out the rotor and placing in the rotor pit (The rotor lifting device will be supplied by KSEB).

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 (270 Nos x 2)

Conducting ELCID test on the core to ensure healthiness of the Core after the work

Re-insulating the stator overhang surge ring with class ‘F’ insulation.

Reinsulating existing main Bus bar with class F insulation

To & fro transport charges for transporting stator bars and core materials including packing

Checking the centering of the stator frame with respective runner and if there is any correction required then the same will be carried out including correction in the lower and top bracket doweling, checking the ovality of the dove tail key bar, replacement of all cores stacking, dovetail key bars with new one and checking the ovality, UT test on key bar welding, Strengthening of dove tail key bars supporting bars by providing vertical ribs and replacement of core lock studs and locking the core-( Scope covers replacement of entire core laminations of existing stator core and none of existing laminations shall be reused even if they are good and all dismantled core materials shall be handed over to KSEBL)

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

Re-Insulation Of 18 Nos. Rotor Poles. Removing the V blocks, pole to pole connections, removing the pole locking keys and removing the poles from the rotor., removing the old insulation by chemical washing, removing the sharp edge using fine emery, removing the surface kinks in hydraulic press, shaping and forming the coils before insulation using special jigs and fixtures checking the bar healthiness using crankchecker, brazing the cranks and weak joints using 1801 silver brazing rod and flux, insulating the pole with class F insulation considering consolidating the coils in the specially made fixtures, replacing the existing pole coil and termination with suitable shape and size. Conducting following tests without yoke. 1. Measurement of winding resistance 2. Surge comparison test 3. Checking profile and dimensions of pole coil 4. AC Impedance measurementc) and replacing all pole coil leads with New Omega design to avoid cut during operation and Pole to Pole connection shall be made suitable for mechanically strong and electrically perfect bolted type connection, conducting contact resistance test after assembly, , and re-fixing the poles, locking the poles with keys, re-fixing the V blocks with new insulation making the pole to pole to connection including necessary supply of insulating tube washerand testing

To & fro transportation and packing charges for shifting the poles from Power station to factory and vice versa.

Re-conditioning of slip ring unit and re insulating the DC bus bar from slip ring to end connection to the pole

UT and DPT test on rotor shaft, bearing pads, turbine shaft and runner blades.

Coupling of rotor and turbine shafts, assembling the Generator and completing aligning of the machine, re-assembling the slip ring chamber, upper and lower bracket, bearing assembly, level checking, oil filling and circulation and assembling of all related components and entire assembling works in order to bring back the machine into service condition.

Vibration (Spectrum) analysis to be carried out and maintaining vibration level within limits. Alignment and In- situ balancing to be done paying attention to the reconditioned poles.

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

Description of Work / Item(s)

Total

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

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