Repairing of 11/0.4kv 250 and 400 KVA Copper wounded Damaged Transformer

Handling and dragging of transformer from stacking yard to repairing hall including opening of top cover plate.

Opening of tap changer connection detanking of core and coil assembly, checking of transformer winding to assess the extent of damage.

Cleaning, removing the rust of tank etc of the repairable transformer and painting of inside of transformer tank with zinc chromate (Yellow) in two coats with spray painting machine. Zinc chromate (Yellow) shall be supplied by the contractor.

Dismantling of core and coil assembly, opening of top yoke core, lamination. Removing of HV and LV Leg coils for assessing its reuse, reuse of major insulating material if possible, checking and recording of physical dimensions of coil.

Reconditioning of minor damaged in HV/LV leg coil/ Strip of transformer. work includes removing of damage part DPC insulation and providing new DPC on same HV coil/LV Strip should be properly cleaned and should be made of same size as of original .

Reconditioning of LV Leg coils including removing of old double paper covering and cleaning of strip .Then providing double paper covering . Double paper covering other allied materials shall be provided by the contractor.

‘‘Making of complete LV leg coils from new/reconditioned DPC Strip of same size, number of turns and dimension as old one.

Reconditioning of HV wire including removing of old double paper covering and cleaning of wire .Then providing double paper covering . Double paper covering other allied materials shall be provided by the contractor.

‘‘Making of complete HV wire from new/reconditioned DPC wire of same size, number of turns and dimension as old one.

Assembly of core and coils and fitting of top yoke and other parts. Replacement of insulation such as press board, craft paper, making support between adjacent section by insulating spacers and wrapping etc. shifting of repaired core coil assembly and placement inside the oven for proper dry out.

Taking out the core coil assembly from oven and shifting the same in assembly yard. Connection of HV Coils and its delta formation, LV connection and its star formation. Fixation of insulating material wherever necessary. Tanking out leads fortap changer contact surface between movable and fixed contacts, tap changer should operate smoothly and there should be no gap between fixed and moving contacts. Retightening of core, coil assembly to match with tank dimension. Clearance between coils, core and tank body to be as per design so that unnecessary losses are avoided. Retanking of core and coil assembly, refitting of tap changer assembly in operating condition and electrical connection of the tap changer.

Dragging out empty tank form yard to repairing hall

Fitting of complete accessories of H.T. & L.V. Bushing and Bushing Rod on H.V. & L.V. side of transformer.

Refilling of reclaimed transformer oil having sufficient dielectric strength and IR Value. Shifting the transformer to testing yard. Refitting of top cover plate, and fixing of rubberized cork sheet, breather assembly after filling of dry silicagel.

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.

Painting outside of the tank by synthetic enamel paint of smoke grey shade in two coats after providing red oxide primer. Red oxide primer and synthetic enamel paint shall be provided by the contractor.

M/S A R ENTERPRISES

INDIA SUPPY CORPORATION

M/S KRISHNA CONSTRUCTION COMPANY

M/S A R ENTERPRISES

M/S KRISHNA CONSTRUCTION COMPANY