providing and fixing of tap changer and repairing of transformer core for transformer sr . no . 7568 at sub station no . - 1 , as per detail given below , disconnecting supply , discharging , opening the ht and lt side connection of 4 mva 33/6 . 6 kv power transformer compete checking and finding fault of transformer sr . no . 7568 at sub station no . -1 , draining the oil from transformer and store in clean drums and complete checking and tacking out core from tank of transformer and checking and testing of the all accessories like mog , bucolz relay , oti , wti , hv & lv side bushing of transformer etc . complete job including hydra charges at sub station no . -1 for transformer sr . no . 7568 . , complete servicing , overhauling and repairing of 33/6 . 6 kv 4000 kva transformer core , removing and cleaning of carbon from core , providing and fixing of new spacers in place of damaged and brunt spacers and providing proper insulation between core and winding of transformer , also arranging and making core and proper tighting of core support nut and bolt for batter operation of core . providing of required hard wares etc and improving of ir value of transformer sr . no . 7568 at ss-1 , complete dismantling the all accessories and opening the top cover of off load tap changing switch and opening all the taping connection of 7 position off load tap changing switch , connection plate , opening and tacking out off load tap changing switch of transformer from transformer providing and fixing of new 7 position 200 amps off load tap changing switch for proper operation of transformer and providing of new gas ket packing and required hard wares etc of off load tap changing switch of transformer reconnecting all the connection of transformer and off load tap changing switch and tacking ir value and complete testing , commissioning 4 mva transformer complete job at sub station no . -1 transformer sr . no . 7568 . , complete heating the core and retaking the core in to transformer tank of 33/6 . 6 kv 4000 kva transformer including hydra charges , re fixing off top cover including providing of gas ket and also fixing of all accessories like mog , bucolz relay , oti , wti , hv & lv side bushing of transformer etc complete job refilling of fresh transformer oil into the tank and filtration of oil and complete job at sub station no . -1