rectification of defective stator coils

Amount

Charges towards de-soldering both the pole jumpers, removing the ‘ V ‘ block and damper coils series link.

Charges towards removing the 8 Nos. static key and 8 Nos. sliding key per pole with special jigs and hydraulic jacks

Charges towards lifting of rotor poles after ensuring all connections are disconnected and by using suitable lifting device.

Charges towards removing the top coils by de-wedging and removing the overhang bandings with special jigs and fixtures

Charges towards removing the bottom coils by de-wedging and removing the overhang bandings with special jigs and fixtures.

Charges towards cleaning the carbon deposits completely with suitable method (dry ice cleaning).

Charges towards removing the old failed insulation and re-insulating on both sides overhang portion on released slot insulation healthy top coils and testing The following tests are to be carried out : 1) IR value at 5 KV before HVAC test 2) HVAC test at 18 KV 3)IR value at 5 KV after HVAC test

Charges towards removing the old failed insulations on slot portion and both overhang portions and re-insulating slot portion and both sides overhang portion with Class F insulation including testing. The following tests are to be carried out: i) IR value at 5 KV before HVAC test ii) HVAC test at 23 KV iii)IR value at 5 KV after HVAC test iv)Tan Delta and Capacitance Measurement.(This is applicable for those top coils where the slot insulation failed during HV test.)

Charges towards installing the spare/re-insulated tested bottom coils with Class F insulation (Spare coils shall be supplied by TANGEDCO) with using fresh liners, end banding the overhang portion with fiber tapes and cards using the binding cement of epoxy resin.

Charges for installing the spare/re-insulated tested top coils (Spare coils shall be supplied by TANGEDCO) with using fresh liners, wedges, end banding the overhang portion with fiber tapes and cards using the binding cement of epoxy resin, soldering the non-connection and connection side end ferrules and jumpers and insulating the jumper joints & providing end caps.

Charges towards replacing the worn-out wedges and tightening the coils in slots with new wedges and liners. (if necessary).

Charges towards removing the old bandings overhang portion of the coils cleaning with suitable cleaning agents, banding with epoxy resin and curing. (if necessary).

Charges for Re-soldering the non-connection and connection side end ferrules and jumpers and insulating the all joints

Charges for re-positioning the pole in the rotor spider, locking the keys, fixing the ’V’ blocks with suitable insulation

Charges for making end connection, locking the jumpers and connection links with suitable insulated locks, soldering the end connection.

Charges for cleaning of stator and rotor windings and drying out

Charges for following test on stator Stator: i) IR value at 5 KV megger before and after HV AC test. ii) HV AC as per instruction of field engineers. iii) PI value at 5 KV megger. iv) PI value v) Winding resistance vi) Tan Delta at 11 KV in the steps of 0.2VL, 0.4VL, 0.6VL, 0.8VL and 1.0 VL and Commissioning of machine

CGST in % (For Bidders inside TamilNadu)

SGST in % (For Bidders inside TamilNadu)

IGST in % (For Bidders outside TamilNadu)