REPAIR MAINT OF EXTERNAL ELECTRIC HT INFRASTRUCTURE ALONGWITH CONNECTED WORKS UNDER GE MIS MHOW

M&L for disconnecting carefully electrical connection from both HT/LT (primary & secondary) sides of the transformer, keeping them at safe side and taking the transformer out from the plinth with the help of crane, indoor/outdoor type of capacity 500 KVA to 750 KVA, 11 KV 0.433 KV, step down any make for carrying out complete repair/ overhauling (only in case of failure) which shall comprise of the following:- (a) Lifting, transporting, handling, the transformer to workshop and Opening the top cover of the transformer by unscrewing nuts, bolts, washers etc. including disconnecting core assembly from HT/ LT bushing and lifting the same gently and taking out from the shell (container/ body) of the transformer. (b) Draining out transformer oil from the above said transformer in container/ drums and keeping it in safe custody for reuse. (c) Cleaning the transformer body from inside, removing deposited dirt/ sludge/ foreign particles etc. from the bottom body of the transformer with appropriate chemical solution and drying up the shell from inside before refilling of the transformer oil. (d) M&L for cleaning and washing thoroughly core and windings of the transformer by hosing down with clean dry oil conforming to IS 335/1983, removing deposited dirt/sludge/ foreign particles from the windings/ core, thorough inspection of windings, providing insulations to leads and terminals, heating/ drying/ baking complete carefully and thoroughly inside the heating chamber at suitable temperature to obtain required value of insulation resistance etc. all as directed by Engr-in-charge.

(e) Lifting and refixing core assembly inside the transformer shell gently and carefully, connecting primarył secondarył Neutral connections to the bushings assembly, fixing of tap change over including tightening of nuts, bolts, washers of the core to reduce humming noise all as directed. (f) Refilling the filtered transformer oil in the shell of transformer complete. (g) Refixing the top cover including replacement of cork sheet? gasket 8mm thick, tightening of nuts/ bolts/ washers etc. and replacement of breather with silica gel crystal type all as directed by Engr-in charge. (h) Lifting shifting to the place from where removed or to any location as directed and re-installing the transformer including connecting primarył secondarył neutral connections eto, all as directed by Engr-in-Charge. (j) The inspection of transformer shall involve the following checks:- (i) Checking of all clamps, nuts, bolts including core bolts & cover fixing bolts. (ii) Checking all brazings, joints, tap heads and connection joints. iii) Checking all jumpers, terminations/ connections inside the transformer. (iii) Inspection of tap changer, checking the moving and fixed contacts for contact wear and connection to winding. (iv) Checking the Buchholtz relaył conservator MOG. (k) Conduoting the tests on oore and windings as per IS like ratio, magnetic imbalance, short circuit etc. in presence of Engr-in-Charge and test results shall be signed by both the parties i.e. contractor and Engineer-in-Charge. Note:- Any damage to insulators/ bushes/ windings etc. while in the custody of the contractor shall be made good at no extra cost to Department. The serviceability of the transformer shall be checked and confirmed by the contractor before taking into his custody. (i) M&L for rewinding /re-insulation of HT/LT (primary/ secondary) coils, bushes, studs, Transformer oil, cable box, replacement of buchholtz relay/ MOG etc will be measured and paid separately.

All as per item No.01, above, but for transformer indoor/outdoor type of capacity upto 400 KVA complete all as specified and directed.

Supply and fix Transformer Gaskets and seals made from a blend of nitrile rubber and cork complete for capacity 100 KVA to 750 KVA transformer including taking down UNSV gasket complete all as specified and directed.

Supply and fix 11 KV HT bushing & brass/copper studs, gasket with-100 kVA to 750 KVA including taking down UNSV HT Bushing complete all as specified and directed.

Supply and fix 11 KV LT bushing & brass/copper studs, gasket with-100 kVA to 750 KVA including taking down UNSV LT Bushing complete all as specified and directed.

M & L in replacement of wornout winding made out of paper covered super enamelled copper complete. wire as per existing guage/ size complete all as specified and directed.

M & L in replacement of wornout winding made out of tripple paper covered solid copper wire as per existing guage/ size complete all as specified and directed.

M&L for replacement of breather assembly transparent MS body with top and bottom portion pressed with metallic cover, filled with silica gel blue in colour and suitable for fixing on existing pipe of size 15/20/25 mm dia or as per site requirement/ capacity of Transformer up to 750 KVA including taking down UNSV breather assembly complete all as specified & directed by the Engr-in-Charge.

Supply & repalcement of silica jel crystal complete all as specified and directed.