For repairing of 25 KVA Damage Transformer at Workshop Jhunsi (Old Shed) under E.W.D Prayagraj.

Handling and dragging of transformer from stacking yard to repairing hall.

Cutting of Sealed transformers top cover plate smoothly and uniformally by gas/chisel cutter or opening of top cover plat and detanking of core and coil assembly.

Dragging of the tank from the repaired hall to yard. & cleaning oil and dust etc. and scraping the rust etc and Washing of Transformer tank with Caustic Soda & water, Caustic soda shall be provided by contractor

Painting of inner side of transformer tank and channels with heat proof zinc chromate paint of good quality (Berger, Nerolac, Jenson & Nicholson etc) shall be

Dragging out empty tank from yard to repairing hall.

Dismantling core and coil assembly and cleaning of dust and dirt from the core assembly and checking of LV and HV leg coils for assessing its reuse, rechecking and recording of physical dimensions of coil and cleaning of core and their components etc.

Reconditioning of the damaged LV leg coils (3 Nos) of T/f old and damage DPC insulation is to removed and new DPC insulation confirming to IS: 1271/53 is to be provided on LV strips after cleaning of strip LV coil should be made of same size.

‘‘Making of complete LV leg Alu. Leg coils identical to original one with same number of turns, weight etc providing super enameled / DPC conductor/ Strip confirming to IS 1971 /53 in place of old and damage coil. Alu. coil, wire strip will be provided by the department. All coil assembly of identical voltage shall be interchangeable without requiring any special equipment. Coil shall be supported between adjacent sections by insulations, spacers, beamers and other insulations.Rewinding shall be arranged to ensure free circulation of oil to reduced hot spots in winding. The insulation of coil shall be treated with suitable insulating, varnish or equivalent compound to develop the full electrical strength of winding as per original design.

‘‘Making of complete HV leg Alu. Leg coils identical to original one with same number of turns, weight etc providing super enameled / DPC conductor/ Strip confirming to IS 1971 /53 in place of old and damage coil. Alu. coil, wire strip will be provided by the department. All coil assembly of identical voltage shall be interchangeable without requiring any special equipment. Coil shall be supported between adjacent sections by insulations, spacers, beamers and other insulations.Rewinding shall be arranged to ensure free circulation of oil to reduced hot spots in winding. The insulation of coil shall be treated with suitable insulating, varnish or equivalent compound to develop the full electrical strength of winding as per original design.

Assembly of core and coils and fitting of other parts requiring replacement such as press board, making supports between adjacent sections by insulating spares and rapping etc & tapping etc. (Breezing/soldering) required, shall be arrange by the contractor.

Shifting and keeping the assembled core coil etc. in Oven from the repairing and assembly place.

Taking out assembled core and coils assembly from the OVEN and shifting to repairing hall.

Retanking of complete assembly into painted tank and lightening of the assembly in the tank safely. Fitting of all accessories of the transformer.

Welding of repaired transformers including of top cover plate by electric core welding filling of gaps or fixing of top cover plate by properly nuts & bolts to prevent seepage of water..

Painting of t/f outside with super enamel synethics paint of yellow color in two coats after providing primer of red oxide paint etc. paint & painting materials shall be provided by contractor.

Dragging of repaired T/f upto the test cabin/testing place for testing and their re-dragging to yard and its stacking at indentified place after testing

Testing the correctness of connection, DVDF, No load, load loss test (where available), High Voltage, impedance voltage, Short Circuit and open circuit test, Voltage ratio on various tap position.

Punching and welding of M.S. Plate on outside of transformer of size 100 mm x 50mm x 3 mm containing/ punching. (a) of unique number as decided by the department with a punch head. (b) Date of repair.

ganga electrical industries