MID/AN/46

Complete disassembling of motor which includes extraction of rotor out of stator. Removal of old banding from both ends of the rotor, de-soldering all the 72 connections of the strips to make the strips free to extract from respective slots. Extraction of all 144 Nos. of strips from 72 Nos. of rotor slots. Cleaning the slots with suitable chemical/ solvents and rebuilding, reconditioning the damaged slots of rotor and fabrication, providing and fitting coils of rotor by way of insertion of 144 Nos. of new copper strips of similar Electrolytic value/ grade in 72 Nos. of rotor slots -insulation with new “F” class insulation material such as glass, tape, mica tape, slot liner , glass tape, wedges of mica, etc., soldering of all the 72 connection at both ends of the rotor and the connection connecting the rotor winding the rotor cable leads. Applying Becktol Red/Grey varnishing with class F Varnish of reputed make. Drying out the rotor at optimum controlled temperature as per standard practice and continuing the process till the standard max./reqd. IR Value and PI value is achieved. Providing / application of glass fibre resin banding at both ends of the rotor for over- hang portion of the rotor winding, varnishing the bands and providing/ fitting in position of rotor connection leads of actual length and specification. Complete job including the cost of material after deduction of rebate on old material/scrap (copper), hire charges for tools and tackles required during the execution of job and labour charges.

Straightening alignment settings of solid shaft of 650 HP, 485 KW 6.6. KV. H.T. motor, re-metaling/ depositing of metal on worn out portion on N.D.E & D.E of rotor shaft using low heat electrode followed by machining to bearing size. Repairs to end covers by enlarging the bore of the end cover bearing housing on DE & NDE by enlarging the bores of housing. Providing, fabrication, and fitting in position of sleeves into the enlarged bores followed by machining / polishing to achieve specified fit for outer cone of the bearings. The job includes dynamic balancing of the rotor after rewinding / repairs on balancing machine.

Fabrication, Providing and fitting of copper coils of stator by VPI procedure. The job includes De-soldering all the 54 connections of the stator coils to make each coil free for extraction from respective slots. Stripping out all the coils from the stator, checking out all the laminations after proper cleaning of core/ slots making it free from oil / grease/ other deposition and reconditioning of damaged slots/appropriate preparation of the stator for rewinding. The slot portions are to be wedged at the ends, centre and magnetic putty is to be inserted with adequate pressure to enhance flux linkage. Complete fabrication of the stator coils by way of fabrication of 54 No. of new copper coils from the enamel poly mica covered copper wire of suitable gauge size, shape and electrolytic grade 99.9% as per original copper wire used for old original coil. Insulation of coils with the new “F” class insulation material of high quality such glass fibre or polyester and mica impregnated or glued together with epoxy, polyester amide (polyamide or polyimide), polyurethane or other resins having superior thermal stability, slot liner, slot spacers, glass tape, fine cotton tape, wedges of mica textile etc. Insertion of new coils in 54 No. of slots of stator with the help of nomex paper and separator wedges and also insertion of packing/anti vibration blocks and locking the same properly. The coil ends must be rigidly supported and adequately braced with binding rings or tapes to prevent their movement and also absorb shocks and vibrations during excessive over-loads, starting inrush currents, and voltage surges. Insulation of all the 54 No. of coils connections after brazing with eutectic brazing rods (14% of silver brazing rods) by applying in layers of glass mica tape reinforced by the varnished glass sleeves. Insulating the connections of the stator coil and also cleaning connections connecting the complete stator with CRC 226/ lectera. Varnishing the stator with class F Epoxy gel/ varnish coat of reputed make and drying out at optimum controlled temp. as permissible in standard practice. Continuing the drying out process till the required IR Value is achieved. Providing/ fitting in position of stator connection leads of actual length and specification. Complete job including the cost of material after deduction of rebate on old material/scrap (copper), hire charges for tools and tackles required during the execution of job and labour charges.

Providing and fitting of new bearing a) 6248/C3 Ball bearing Complete job including the cost of material after deduction of rebate on old material/scrap hire charges for tools and tackles required during the execution of job and labour charges.

Cleaning of the top bearing oil chamber with flushing oil & providing and re-filling of fresh lubricating oil of actual specification up to the mark. Complete job.

Mounting of 650 HP BHEL make solid shaft 6.6. KV, 485 KW HT Motor at site & shifting the assembled motor and placing on motor skirt. Coupling the motor with VT pump half coupling, restoration of all electrical connections of motor to LRS, motor panels and slip rings, making proper alignment of motor with pump and adjustment thereof. Testing the motor on load for all connected parameters and commissioning for proper operation. Complete job in all respects.

Carriage of motor (Stator and rotor) from the pump house Ranjan to workshop by suitable loading capacity load carrier for safe carriage/ transportation to workshop of the firm for complete rewinding and Carriage of the same from workshop of the firm to lift irrigation station Ranjan after complete rewinding & related tests. (for maximum distance up to 700 km from LIS Ranjan and Reassembling of 650 HP BHEL make solid shaft 6.6. KV, 485 KW HT Motor at site & shifting the assembled motor and placing on motor skirt. Coupling the motor with VT pump half coupling, restoration of all electrical connections of motor to LRS, motor panels and slip rings, making proper alignment of motor with pump and adjustment thereof. Testing the motor on load for all connected parameters and commissioning for proper operation. Complete job in all respects.