Tamil Nadu Generation And Distribution Corporation Limited Tender

STATOR REWINDING (6.6 KV) GVPI Charges towards dismantling the motor, threading out the rotor from the stator core pack, stripping out of old windings, cleaning the slots, conducting hot spot test find out the core damages, removing the stator core pack from the stator yoke by hydraulic press using special jigs and fixtures, rewinding the stator using class ‘F’ enamelled polymica covered electrolytic grade rectangular copper conductors for rewinding coil as per the Original shape and dimension by uing special jigs and dies as detailed in Sl.No.2), pre-staggering the coil with thermopreg, insulating the slot portions using samicapor insulating materials, applying corona protection tapes and stress grading tapes, inserting the coils in to the slots, banding the overhang portions in the surge ring, forming the end connection, fixing 12 Nos. RTDs, preheating, Global Vacuum Pressure Impregnating the winding with core pack in vacuum chamber using suitable poly epoxy resin, baking, testing, refixing the core pack into the stator yoke with special jigs and fixtures in hydraulic press, providing flexible silican cables, applying finishing varnishes including assembling, no load trial run and measuring all no load parameters. Materials: class F” enameled polymica covered electrolytic grade rectangular copper conductors, samicapor insulating materials, corona protection tapes, stress grading tapes 12 Nos. RTDs, poly epoxy resin flexible silicon cables, varnishes.

STATOR CORE RESTACKING: Charges towards mounting the stator body in hydraulic press, removing the core pack from stator body with special tools and machineries after heating the stator yoke with special heating arrangements, segregating the damaged stator core from core pack, removing the old burnt core plate varnishing by chemical treatment, cleaning, removing the surface kinks. Varnishing the stampings in re-varnishing cum conveyor oven to cure the core plate varnish, staggering the core with special tools and machineries, locking and repositioning the core pack to the stator body by hydraulic press and finally conducting the flux loop test to ascertain the restacked core healthiness, cleaning and polishing the slots ready to feeding. Material: New Stator core plate, core plate varnish

ROTOR TESTING & SERVICE: Charges towards threading out the rotor from the stator core pack, cleaning the rotor winding thoroughly using high pressure water, drying out the winding, conducting non- destructive test to the rotor bars and end rings, to ascertain the healthiness of the winding, visual inspecting the rotor in all electrical and mechanical parts, preheating, varnishing and backing in oven, applying finishing varnishes to the rotor , checking the shaft trueness, measuring the bearing fitting tolerance both in housing and rotor shaft. Material: Varnish