Himachal Pradesh State Electricity Board Limited Tender

Dismantling and Repairing works at Site

Dismantling of Bushings and all accessories, Dismantling of Top cover, Disconnecting OLTC/OCTC, taking out Core & Winding unit from the main tank, Hot Oil Jet cleaning of Core & Winding, dismantling the top channels, dismantling /removing the top core from transformer, Removing all damaged insulation, Permali wood/corona ring. Inspecting the windings for any internal damage,if no major damage found in winding, re tapping the Damaged HV Leads with creep papers and replacing the insulation materials like Pre compressed board wherever missing , Repairing the damaged corona ring, Replacing all other damaged press boards / permali wood. Providng and fixing of Gaskets,oil seals and suport insulator (For LV Side ) .Assembling back the top core and top channels LT Testing of the winding (IR, PI, Ratio test, magnetic balance, winding resistance, vector group) Comparing the results with factory test reports, assembling back the core & winding unit inside main tank, Replacement of Gaskets of Top cover, man holes and Bushings. Assembling back the Top cover, Drying out of transformer Nitrogen purging until required values are achieved. Filling the filtered transformer oil under vacuum above core level, erection of HV & LV Bushings, conservators. Topping of transformer Oil in the main tank of transformer, Hot Oil Circulation of entire transformer until required BDV, PPM, DGA Values are achieved. Testing the transformer in Repair Bay . 1.Capacitance and Tan delta of Windings and Bushings, 2.SFRA Test, 3.Core insulation test (between core to clamp, clamp to tank and core to tank), 4.Bushing CT’s and neutral CT Testing (Ratio, Polarity, IR, secondary winding resistance and ratio error calculations) 5.Oil testing of Transformer Main tank and OLTC (BDV, DGA, Moisture content, Furan analysis, Flash point, pour point, Resistivity, Acidity, Sludge content, Interfacial tension (IFT), Density, Viscosity, Tan delta. 6.Continuity test of OLTC during one complete cycle of operation . and all other requiste test mentioned in Bid document.

Optional work ( If winding found damages )