Repairing of 100 Kva HT transformer at Lift irrigation scheme Chainable of MISP Pattan.

Amount

Mechanical transportation, loading, unloading of transformer using minitruck like Tata mobile, Bolero camper or similar from site to workshop and then from workshop to site after necessary repairs.

Dismantling of 33/0.4 kv or 11/0.4kV transformer by way of disconnecting of all HT and LT connections, opening of top lid, draining out of T. Oil and its safe placement for further refilling, taking out of coils after removal of core assembly, etc. Job also includes detaching of core HV/LV coils.

Rewinding of Aluminium wound 3-Ph 11/0.44kV distribution transformer by way of P/F of HT Aluminium wound torroidal coils of proper gauge, insulation and separated with proper specification by way of using silicon taping, teflon paper, cork sheet and Bakelite sheets. Complete winding to be done and connections coming out duly insulated. LT windings shall be circular and concentric with HT windings on the outside.Approximate weight of each HT coil = 3.5 Kgs) The connections shall be connected in delta or star for primary winding and secondary winding as specified, the neutral with separate insulated terminal. The job also includes decarburising laminated core. The core then firmly fixed with channelled frame to prevent noise and vibration. The arrangement of winding shall made robust in electrical /mechanical construction and should permit free circulation of oil to avoid hot spots. (Note: The unserviceable scrap aluminium windings extracted shall be property of the firm and is taken into account for estimation of rates).

Dehydration of transformer core in Electrically operated oven

Filtration of T oil for removal of carbon, impurities and moisture

Providing of Transformer oil (preffered make: Indian oil servo/HPCL/Power oil

Providing and Fitting of 12mm LT bush rod.

Providing and fitting of rubber gasket with nuts and bolts to the transformer tank.

Providing and fititng of 185sqmm Aluminium thimbles for bush rods

Complete assembling of the transformer by way of fitting of HT/LT coils in the tank. Job further includes closing of the transformer lid by way of fitting of existing nuts/bolts and gaskets. Refilling of t.oil upto required level in tank. Reconnecting of HT/ LT connections and testing.

ishaq electricals