Reconditioning of 2.5 MVA AVR No. I, by way of replacement of damaged components and filtration of transformer oil of AVR along with allied Works at Tawi pump House Jammu

Amount

Reconditioning of Isolating unit of 2.5 MVA AVR No I by way of dismantling the damaged insulators and bush rods and providing and fitting of 03nos new bush rods (fabricated out of brass as per sample provided) along with insulators and requisite no. of nuts and washers, removing carbon deposited on the inner surfaces by cleaning cabinets from inside using petrol, emery cloth and then applying epoxy paint etc. Cleaning and polishing the make and break links with 0 Grade emery cloth, petrol, cotton cloth& then making adjustment.Replacingfibre arms of breaking unit with providing and fitting new arms as per sample, oiling and greasing of all the moving points. Job also involves cutting of damaged Al thimbles, preparing ends of cable and P/F new Al. thimbles as per sample. Checking IR value between phases and body and across all the three phases. Testing and commissioning on load. Complete job includes cost of material and labour charges.

Dehumidification and filtration of Insulating oil filled in AVR consisting Main transformer unit( step up/stepdown transformer and Buck boost Transformer) and Voltage regulator of 2.5 MVA AVR No I installed at Tawi Pump House Jammu by way of purification of Transformer oil by various processes such as heating ,filtration, dehydration and degasification of transformer oil in the filtration machine at site to remove moisture , acid ,gases and sludge present in the insulating oil in order to improve Di -electric strength of oil (Approx. qty of oil to be filtered is 3800 litres) and topping up with new transformer oil 570 Liters (approx.) Replacing damaged breather with new one and providing and filling of new silica gel. Complete job includes cost of material, checking BDV of Transformer oil, hire charges, to and fro carriage charges of filtration machine and servicing of main transformer and other labour charges.

Replacement of worn-out tag and tail assembly and carbon rollers of 2.5 MVA AVR No. I by way disconnecting supply from VCB and therefore isolating all the threeisolating units.Dismantling of top tank cover taking out of hand wheel after disengaging motor driver from the regulator. Disconnecting the flexible cable from the tank terminal board, lifting of all three limbs along with contact bar with the help of crane and shifting the same in the main hall of Tawi Pump House, lowering the same on the drip tray and allowing it to drain reasonably. The job further involves extracting out all the 48 No. pitted /worn out carbon roller assemblies and 48 No. worn out tag and tail assembly.The job involves cleaning and smoothing the marked /pitted portion the coil surface carefully with grade 0 emery cloth by rubbing gently around the coil surface in the direction of winding.Washing out the coil assembly with the fresh transformer oil so that copper dust left on the coil get washed away then drawing out the coil surface with the help of dry cotton rags. P/F new 48 Nos carbon rollerassemblies, new 48 Nos tag and tail assembly as per sample. Checkingthat all the roller assemblies run freely on the spindle and carbon brushes on the coils with minimum play, replacing the rotate plate locking with screws and maintaining the brush lead position.Lifting the complete unit and lowering it in the main tank of the regulating unit with the help of crane in such a way that no part /component is disturbed/damaged. the job also includes replacement of burnt-out PCB relay, limit switch-04 Nos. voltmeter as per sample. Job includes making of connection of cables of isolating unit, refitting of tank cover, making connection s of all the control circuit wiring and testing AVR on full load. Complete job includes cost of material, labour charges, hire charges for crane required for the execution of job

M/S RAGHUNATH MECHANICAL AND ELECTRICAL ENGINEERING WORKS

G S ENGINEERING WORKS