SPECIAL REPAIR REPLACEMENT OF 11 KV DISTRIBUTION TRANSFORMERS AGAINST BER INCLUDING VCBs AND ASSOCIATED PROTECTION SYSTEM AT AFS KANPUR

Supply, install, testing & commissining out door type transformer having no load voltage ratio at rated voltage 33/11 KV , 5000 KVA oil immersed, naturally cooled ONAN (oil natural, air natural) 3 phase 50 Hz, vector group, HV winding delta connected; LV winding star connected with neutral brought out; vector group Dyn11 and ON load tap changer with AVR & RTCCP +5% to -15% on the 33 kV winding in 1.25% steps, with neutral/rated tap and total positions explicitly . tap changing switch, copper double wound, LV side provided with 3 phase and neutralthe temperature rise above a maximum ambient temperature of 50°C shall not exceed (i) 50 K for top oil, measured by thermometer, and (ii) 55 K for average winding, measured by the resistance method, in accordance with IS 2026 (Part 2) with first filling of transformer oil conforming to Clause 17.1 of the Particular Specificationsand transformer Transformer insulation and dielectric withstand levels shall conform to IS 2026 Parts 1 and 3. The winding insulation shall be conventional mineral-oil-immersed cellulose insulation suitable for the specified temperature-rise limits. complete all as directed and specified with and including the following fitting and accessories including first fill of transformer oil necessary mounting on PCC floor mounted as per manufacture's recommendation specifications :-

(a). Lifting lugs, Top cover lugs & jacking pad (b) Earthing Terminals. (c) Conservator with oil gauge glass, filling hole with plug and drain plug (d) Transformer Drain valve -02 Nos (e) 04 Nos Bi Directional plain/flat rollers (f) Explosion vent with Diaphagm (g) Thermometer pocket (h) Air vent plug (j) First Fill silica gel Breather (k) Rating & Diagram plate, inspection cover, Terminal making plate. (l) Cooling Radiators (m) LV Neutral bushing brought out for external earthing. (n) Complete first filling of transformer oil conforming to Clause 17.1 of the Particular Specifications, including oil required for processing, filtration and commissioning, together with one additional complete sealed drum of the same approved oil as contingency.(o) Buchholz relay double float with contact for Alarm & trip contact. (r) Winding Tempreture indicator with Alarm contact. (s) Marshaling Box. Note:- Before commencement of manufacture, the contractor shall submit the transformer drawings, Guaranteed Technical Particulars, guaranteed loss and impedance schedule, Type test certificate of similar rating transformer, Quality Assurance Plan, Inspection and Test Plan, valid type-test reports and proposed FAT procedures for approval in accordance with Clause 21.2 of the Particular Specifications. The transformer shall not be dispatched without completion of the approved FAT and issue of a written inspection/release note by the GE or Accepting Officer. The cost of inspection and testing shall be included in the quoted rate.(B)Insulation system Conventional mineral-oil-immersed cellulose/paper insulation suitable for the specified temperature-rise limits in accordance with IS 2026 (Part 2). Dielectric insulation levels shall comply with IS 2026 (Part 3), as follows: (a) 33 kV winding, highest voltage for equipment Um = 36 kV: Lightning impulse withstand voltage — 170 kVp; separate-source power-frequency withstand voltage — 70 kV rms for 1 minute. (b) 11 kV winding, highest voltage for equipment Um = 12 kV: Lightning impulse withstand voltage — 75 kVp; separate-source power-frequency withstand voltage — 28 kV rms for 1 minute. The insulation level of the neutral terminal shall be confirmed according to the system-earthing arrangement and approved insulation-coordination study.(ii) The no-load loss at rated voltage and frequency shall not exceed 5.0 kW, and the load loss at rated current on the principal tap, corrected to 75°C, shall not exceed 36.0 kW. No positive tolerance shall be permitted, and both losses shall be verified during routine testing in accordance with IS 2026.

Supply, install, testing and commissioning of 11 KV, 3ph, 50Hz, iindoor type, factory-assembled, metal-clad, compartmentalised, floor-mounted, extendable, horizontal draw-out VCB switchgear, complete with VCBs having rated short-circuit breaking current not less than 18.4 kA and assembly short-time withstand current not less than 18.4 kA for 1 second, all as specified in Clause 24A of the Particular Specifications. insulation level-12KV/28KV/75KVP, SC rating-18.4 KA for 1 Sec. IEC 62271-200:2021 including Amendment 1:2024 for the switchgear assembly, IEC 62271-100:2021 including Amendment 1:2024 for the VCBs, IEC 62271-1:2017 including Amendment 1:2021, and IEC 60529 for enclosure IP classification overload and earth fault protection, ammmeter, voltmeter and of current rating not less than 800 Amps including necessary connection with existing cables including following details specification complete all as specified and directed.:- (a)a) The six-VCB board shall comprise two incomer VCB panels, one bus-coupler VCB panel with bus-riser chamber and three outgoing-feeder VCB panels. The main bus shall be divided into Bus Section A and Bus Section B. Incomer-1 shall feed Bus Section A and Incomer-2 shall feed Bus Section B. The two bus sections shall be connected through the bus-coupler VCB. The bus-riser chamber shall not be counted as a separate VCB panel. The provisional distribution shall be two outgoing feeders on Bus Section A and one outgoing feeder on Bus Section B. The final feeder allocation and designations shall be shown on the approved single-line diagram without changing the total quantity of six VCBs. (b)Digital numerical relays for earth fault, over current protection, as per OEM recomendation for normal load and for motor load . (c)high speed trip relays.(d )Closing coil, trip coils of 110V, DC (e) VCB will be holrizontal break and horizontal draw out type. (f) VCB panel shall be suitable for local/remote control. (g) The panel will be provided LED indicators as specified by OEM (h) h) Current transformers and voltage transformers shall be cast-resin, dry-type instrument transformers suitable for a 12 kV system with 28 kV rms/1-minute power-frequency withstand and 75 kVp lightning-impulse withstand, conforming to IS 16227/IEC 61869 series and Clauses 22 and 22.1 of the Particular Specifications. (i) The provisional CT schedule for tender pricing shall be as follows: (i) Transformer incomer panels: 400/5 A, with two independent 5 A secondary cores. (ii) Bus-coupler panel: 800-400/5 A dual primary ratio, with two independent 5 A secondary cores. (iii) Outgoing-feeder panels: 200-100/5 A dual primary ratio, with two independent 5 A secondary cores. For every CT, Core 1 shall be for metering, Class 0.5S, minimum 15 VA burden and instrument security factor FS ≤ 5. Core 2 shall be for protection, Class 5P20 and minimum 15 VA burden. CTs shall withstand not less than 18.4 kA rms for 1 second and a minimum peak current of 46 kA. Where transformer differential or restricted-earth-fault protection is required, a separate third Class PX protection core shall be provided. Its knee-point voltage, secondary winding resistance and excitation current shall be determined through the approved protection calculation. One withdrawable cast-resin VT/PT set shall be provided for each bus section and these cubicles are included within the quoted set and are over and above the six VCB count. The ratio, secondary windings, accuracy classes, burdens, fusing and earthing shall comply with Clause 22.1. Final CT and VT ratios shall be confirmed through the approved load-flow, short-circuit, protection and metering studies before manufacture. (j) Spring charging motor 0f 230V, AC (k) Auxiliary relay for transformer protection having buch alarm, Oil Temp alram & Wdg Temp alram for Transformer fedder only (l) Relay seting after commissioning of VCB according to load/fault condition with secondary injection.

Supply, install, testing and commissioning of 11 KV, 3ph, 50Hz,indoor type, factory-assembled, metal-clad, compartmentalised, floor-mounted, extendable, horizontal draw-out VCB switchgear, complete with VCBs having rated short-circuit breaking current not less than 18.4 kA and assembly short-time withstand current not less than 18.4 kA for 1 second, all as specified in Clause 24A of the Particular Specifications. insulation level-12KV/28KV/75KVP, SC rating-18.4 KA for 1 Sec. IEC 62271-200:2021 including Amendment 1:2024 for the switchgear assembly, IEC 62271-100:2021 including Amendment 1:2024 for the VCBs, IEC 62271-1:2017 including Amendment 1:2021, and IEC 60529 for enclosure IP classification, overload and earth fault protection, ampmeter, voltmeter and of current rating not less than 800 Amps including necessary connection with existing cables including following details specification complete all as specified and directed.:- (a) (a) The seven-VCB board shall comprise two incomer VCB panels, one bus-coupler VCB panel with bus-riser chamber and four outgoing-feeder VCB panels. The main bus shall be divided into Bus Section A and Bus Section B. Incomer-1 shall feed Bus Section A and Incomer-2 shall feed Bus Section B. The two bus sections shall be connected through the bus-coupler VCB. The bus-riser chamber shall not be counted as a separate VCB panel. The provisional distribution shall be two outgoing feeders on each bus section. The final feeder designations shall be shown on the approved single-line diagram without changing the total quantity of seven VCBs. (b)Digital numerical relays for earth fault, over current protection, as per OEM recomendation for normal load and for motor load . (c)high speed trip relays.(d )Closing coil, trip coils of 110V, DC (e) VCB will be holrizontal break and horizontal draw out type. (f) VCB panel shall be suitable for local/remote control. (g) The panel will be provided LED indicators as specified by OEM (h(h) Current transformers and voltage transformers shall be cast-resin, dry-type instrument transformers suitable for a 12 kV system with 28 kV rms/1-minute power-frequency withstand and 75 kVp lightning-impulse withstand, conforming to IS 16227/IEC 61869 series and Clauses 22 and 22.1 of the Particular Specifications. (i) The provisional CT schedule for tender pricing shall be as follows: (i) Transformer incomer panels: 400/5 A, with two independent 5 A secondary cores. (ii) Bus-coupler panel: 800-400/5 A dual primary ratio, with two independent 5 A secondary cores. (iii) Outgoing-feeder panels: 200-100/5 A dual primary ratio, with two independent 5 A secondary cores. For every CT, Core 1 shall be for metering, Class 0.5S, minimum 15 VA burden and instrument security factor FS ≤ 5. Core 2 shall be for protection, Class 5P20 and minimum 15 VA burden. CTs shall withstand 18.4 kA rms for 1 second and a minimum peak current of 46 kA. Where transformer differential or restricted-earth-fault protection is required, a separate third Class PX protection core shall be provided. Its knee-point voltage, secondary winding resistance and excitation current shall be determined through the approved protection calculation. One withdrawable cast-resin VT/PT set shall be provided for each bus section and these cubicles are included within the quoted set and are over and above the six VCB count. The ratio, secondary windings, accuracy classes, burdens, fusing and earthing shall comply with Clause 22.1. Final CT and VT ratios shall be confirmed through the approved load-flow, short-circuit, protection and metering studies before manufacture. (j) Spring charging motor 0f 230V, AC (k) Auxiliary relay for transformer protection haaving buch alarm, Oil Temp alram & Wdg Temp alram for Transformer fedder only (l) Relay seting after commissioning of VCB according to load/fault condition with secondary injection.

M&L for chemical earthing complete with copper plate electrode 900mmx600mm x 5 mm thick buried directly in ground with top edge of plate not less than 4.5mtr deep below the normal ground level connected to copper strip 50 x 6mm copper strip as main earthing lead and connected and tinted copper bolt, nuts, check nuts ad washers besides brazing at all joints all as directed and connected to earth test point all as specified and directed with and including necessary excavation and earth work, returning filing, removal of extra soil etc, filing adequate quantity of charcoal dust, common salt and MgSO4 upto top of plate, PCC (1:3:6) type C-1 using 20mm graded stone aggregate for earth pit chamber with 40mm x 40mm x6 mm mild steel angle iron frame for cover, pre-cast 50 mm thick RCC cover in (1:2:4) type B-1 using 20 mm graded stone aggregate , reinforcement with 8mm TMT bar @ 75 mm c/c on both way , funnel with wire mesh and 50mm dia galvanised iron pipe light grade for earth lead protection and 40 mm dia galvanised iron medium grade for watering and 8.5 mtr copper strip including testing on completion complete all as specified and as directed

M & L earthing complete with galvanized steel plate electrode 60cm X 60cm X 6 mm thick buried directly in ground (Earth pit not less than 2.25 Mtrs deep below ground level) with top edge of the plate not less than 1.5 Mtr below normal ground level connected to galvanized strip 32 X 6mm size by means of bolts, nuts, check nuts and washer of galvanized iron or of steel, earth lead protected by 40mm dia GI pipe light grade watering pipe 20mm dia GI light grade GI wire messed funnel, alternative layer of charcoal and salt, PCC chamber, recessed for and including RCC cover including all necessary excavation and earth work, earth strips connected to HT/LT equipment testing the earthing after completion all as specified and shown in electrical plate No 3 of MES SSR Pt- I 2009 print, complete all as specified & directed.

Taking down unserviceable BER transformer & Vacuum Circuit breaker including all connected accessories after disconnecting cable coonection carefully and shifting to AGE E/M store yard using necessary man power/transport all as specified and directed.( Note :- Applicable for Sch 'A'(BOQ) item ser No. 1,2&3)