REPAIR AND MAINTENANCE TO HT SWITCHGEAR POWER TRANSFORMER YARD MAINT WITH CONNECTED ITEMS AT 33/11 KV SHEKHAWATI GRID UNDER GE (U) ELECT SUPPLY DELHI CANTT-10

M & L for ON load Centrifuging and dehydration including filteration and cleaning of transformer oil by dehydration machine of 33 KV transformer / Stn transformer at site and topping up deficient transformer oil including testing of samples before and after dehydration and filteration complete all as specified and directed. Note :- (a) Deficient quantity of Transformer oil required for top up shall be measured and paid separately under item No 2 here-in -after as supply only. (b) Test report of dielectric strength shall be recorded after and before of dehydration process. Dielectric strength should be not less than 40 KV in 2.5 mm gap.

Supply only transformer oil of approved quality as per IS having dielectric strength of 45-60 KV in 2.5 mm gap for filling in transformer or for topping up as required and directed.

Material and labour for servicing /testing of line circuit breaker, control panel including outdoor CT, PT and relays in control panel of outdoor SF 6 Gas Circuit Breaker of capacity 1250/800 Amps and rating 36 KV complete as details mentioned as under:- (a) Details of servicing of breaker :- (i) Checking of Closing/Tripping coil assembly (ii) Adjustment of mechanism if required. (iii) Clean the circuit breaker to remove dust and dirt. (iv) Apply a small amount of oil to rotary sections, sliding surfaces, pins, coupling section, etc.use grease for the operating shaft and bearings, and machine oil for other parts. (v) Visual check for rusted,wear/tear parts. (vi) Checking of spring charge mechanism (vii) Visual check for any deformation. (viii) Check for loosened bolts and nuts, broken spring washers and snap pins etc.

(ix) Check for loosened connections, damaged lead wires. (x) Checking of control circuit & tighten the connections if any. (xi) Check close & trip coil. (xii) renewal of Dashpot/shock absorbers . (xiii) renewal of carbon brush of spring charging motor (xiv) Cleaning of porcelain bushing (xv) Checking of limit switch (b) The following test shall be carried out:- (i) Primary Injection Test of outdoor CT / PT (ii) Closing & Opening Timing Test for all three poles. (iii) IR Test with megger in open and closed condition. (iv) Contact resistance test for all three poles (v) Closing coil resistance (vi) Tripping coil resistance.

(c) Testing of following relays of control panel with Secondary Injection Kit ,checking and programming of relay :- (i) Over current and earth fault relay (ii) Line diffrential relay (d) Testing of followig Aux relay:- (i) DC Supply supervision relay. (ii) Trip Circuit suprvision relay (ii) SF 6 gas pressure low. (iii) PT Fuse failure relay (iv) Master trip relay (v) Under voltage relay (vi) Over voltage relay

Material and labour for servicing /testing of transformer circuit breaker, control panel including outdoor CT, PT and relays in control panel of outdoor SF 6 Gas Circuit Breaker of capacity 1250/800 Amps and rating 36 KV complete as details mentioned as under:- (a) Details of servicing of breaker :- (i) Checking of Closing/Tripping coil assembly (ii) Adjustment of mechanism if required. (iii) Clean the circuit breaker to remove dust and dirt. (iv) Apply a small amount of oil to rotary sections, sliding surfaces, pins, coupling section, etc.use grease for the operating shaft and bearings, and machine oil for other parts. (v) Visual check for rusted,wear/tear parts. (vi) Checking of spring charge mechanism (vii) Visual check for rust and deformation.

(viii) Check for loosened bolts and nuts, broken spring washers and snap pins etc. (ix) Check for loosened connections, rust, damaged lead wires. (x) Checking of control circuit & tighten the connections if any. (xi) Check close & triping coil. (xii) renewal of Dashpot/shock absorbers . (xiii) renewal of carbon brush of spring charging motor (xiv) Cleaning of porcelain bushing (xv) Checking of limit switch etc (b) The following test shall be carried out:- (i) Primary Injection Test of outdoor CT / PT (ii) Closing & Opening Timing Test for all three poles. (iii) IR Test with megger in open and closed condition. (iv) Contact resistance test for all three poles (v) Closing coil resistance (vi) Tripping coil resistance.

(c) Testing of following relays of control panel with Secondary Injection Kit ,checking and programming of relay :- (i) Over current and earth fault Relay (ii) Transformer diffrential relay (d) Testing of followig Aux relay (i) DC supply supervision relay. (ii) CB SF 6 gas pressure low. (iii) Master trip relay (iv) Main Buchholz trip (v) Buchholz OLTC Trip (vi) SPR & PRV trip. (vii) Winding temp high trip (viii) Oil temp high trip. (ix) Main Buchholz alarm (x) Winding temp High alarm (xi) Low Oil level alarm (xii) Oil temp high alarm

Material and labour for servicing /testing of breaker/control panel including CT, PT and relays in control panel of VCB of capacity 1250 /800/630 Amps and rating 11 KV complete as details mentioned as under:- (a) Details of servicing of breaker :- (i) Adjustment of mechanism if required. (ii) Clean the circuit breaker to remove dust and dirt. The envelope of the vacuum interrupter and insulating materials shall be wiped with a clean cloth. (iii) Apply a small amount of oil to rotary sections, sliding surfaces, pins, coupling section, etc.use grease for the operating shaft and bearings, and machine oil for other parts. (iv) Visual check for rusted,wear/tear parts.

(v) Check Spring Tension and pitting of the Cluster Contacts. (vi) Visual check for rust and deformation. (vii) Check for loosened bolts and nuts, broken spring washers and snap pins etc. (viii) Check for loosened connections, rust, damaged lead wires. (ix) Check whether the contacts are damaged by arcing. (x) Checking of control circuit & tighten the connections if any. (xi) Check close & trip coil. (xii) Checking of Jaw Contacts Conditions and repair/adjust. (xiii) Replace the jaw contacts,If required. (xiv) Improvement of resistance of epoxy insulator and epoxy body by applying post heated varnish. (xv) renewal of Dashpot/shock absorbers . (xvi) renewal of carbon brush of spring charging motor (xvii) Checking, cleaning, tightening , testing the busbars incl bus chambers, CT/PT (xviii) Checking, cleaning, tightening , testing of support insulator, Spouts etc