REPLACEMENT OF BER TRANSFORMER AND VCBS (IN MAIN RECEIVING STATION OF 33 KV) AT DMRL DRDO AND DLRL AREA UNDER GE I RND KANCHANBAGH HYDERABAD

Supply of 500 KVA capacity (continous loading) indoor type BEE Star rated (Level 2 Energy efficient) 11/0.433 KV step down, 3 Phase, 50 Hz, Dyn 11 vector group, ONAN (Oil Natural Air Natural) copper wound transformer (Electrolytic grade 99.9% pure copper, Core made of first grade Cold Rolled Grain Oriented (CRGO) Core grade MOH or better, suitable for outdoor applications with On Load Tap Changer (OLTC) on HV side having AVR relay and Remote Tap Changer Control (RTCC) for automatic sensing of incoming voltage, automatic operation of OLTC and facility for remote and manual operation of OLTC HV side in range of +5% to -15% in steps of 2.5%, having cable end boxes on HV side suitable for 3x300 sqmm XLPE cable of 11 KV grade, including bus trunking arrangement on LV side including supplying and laying of copper conductor multicore control cable from transformer to HT breaker/panel for safety tripping, complete with all accessories and safety provisions as per relevant IS Code including first filling of filtered dehydrated oil, i/c supplying and grouting of suitable M.S. Channel with all accessories

and transformer shall be confirming to IS : 2026 (Part 1 to Part 5), IS : 1180 and duly ISI Marked and as per CPWD specifications complete in all respects etc as required at site. The maximum flux density in any part of the core and yoke at rated voltage and frequency shall be such that the flux density with + 12.5 percent combined voltage and frequency variation from rated voltage and frequency does not exceed 1.9 Tesla. The permissible temperature-rise shall not exceed 35 degree celsius for oil and 40 degree celsius up to 200 KVA and 40 degree celsius for oil and 45 degree celsius for above 200 KVA for winding. Inside of tank shall be painted with varnish or liquid resistant paint. For external surfaces one coat of thermo setting powder paint or one coat of epoxy primer followed by two coats of polyurethane base paint shall be used. IS: 1180 (Part 3) shall be referred to for paint thickness for normal to medium corrosive atmosphere. For highly polluted atmosphere and special application external paint work shall be as per direction of Engineer-in-Charge. Design ambient condition : a) air temperature 50 degree celsius, b) Relative Humidity 90 % Max, c) Seismic Zone as per location of site, d) Altitude as per location/site.

Noise level Shall not exceed limits as per NEMA TR-1 with all accessories running measured as per IEC 551 / NEMAstandard. The transformer should have QR code which should contain drawing, test report OEM manual,Geo Tag of manufacturing location etc. Marking Each transformer shall be provided with rating plate made of anodized aluminum/ stainless steel material securely fixed on the outer body, easily accessible,as per IS: 1180 Part-3. The entries on the rating plate shall be indelibly marked. Fitting and Accessories : The following fittings shall be provided:- (a) Two earthing terminals with the earthing symbol (b) Oil level gauge indicating oil level at minimum, 30°C and maximum operating temperature; (c) Air release device (for non-sealed type transformers) (d) Rating and terminal marking plates; (e) Silica gel breather (f) Drain-cum-sampling valve (¾″ nominal size thread, IS 554) preferably steel with plug for three phase transformers; (g) Thermometer pocket with cap; (h) Oil filling holes having (1¼″ nominal size thread) with cover (for sealed type transformers without conservator); (j) Lifting lugs for the complete transformer as well as for core and winding assembly;

(k) Pressure relief device or explosion vent above 200 kVA; (l) One filter valve on the upper side of the tank (for transformers above 200 kVA); (m) Unidirectional flat rollers (for transformers above 200 kVA); (n) Inspection hole (for transformers above 200 kVA); (o) HV side neutral grounding strip (where one of the HV bushing terminal is connected to earth); (p) Buchholz relay for transformers above 800 kVA. (q) Arcing horns or suitable rating lightning arrestors for HT side – 3 Nos. (r) Bird guard; (s) Oil temperature indicator and winding temperature indicators for transformers above 200 kVA with suitable tripping mechanism above permissible limit (t) Jacking pads (for transformer above 1600 kVA); (u) Additional Neutral separately brought out on bushing for earthing. (v) Magnetic oil level gauge (for transformer above 1600 kVA) with low oil level alarm contact; (w) Non return valve (for conducting pressure test); (x) Pressure relief device or explosion vent

(y) Monogram Plate (z) Inspection cover (aa) Detachable type radiators with top and bottom shutoff valve. (ab) Oil Conservator with Oil level indicator, minimum level marking and drain plug for all transformers of capacity 50 KVAand above. (ac) Necessary hardware, clamps, lugs etc. for termination on HV/MV etc. for all transformers. Note:- Miscellaneous civil work for fixing of the Transforms platform and make good the cable ducts and plinths etc as per site requirement and all as directed by Engineer in charge.

All as per item No 1 but capacity 400 KVA

All as per item No 1 but capacity 250 KVA

All as per item No 1 but capacity 200 KVA

All as per item No 1 but capacity 160 KVA

All as per item No 1 but capacity 100 KVA