SPCIAL REPAIR/ REPLACEMENT OF POWER TRANSFORMERCAPACITY 02 MVA AGAINST BER AT AF STATION AMLA.

Amount

1. Supply , installing , testing & commissioning outdoor type, step down transformer , 33KV/11KV, AC 3 Phase 50 Hz, 2000 KVA capacity, core type, double copper wound, oil immersed, naturally cooled, oil natural- Air Natural (ON AN) with external cooling tubes with aerial bushing at HV side and cable end box at LV side, delta connected on primary side (HV) and star connected on secondary side (LV) in accordance with vector group DYn-11 and having 7 Nos tap positions for voltage variation from (+) 7.5% to (-) 7.5% of HV in steps of 2.5% each to be changed by off load tap changer gear including suitable foundation of size 3mx3mx2m, IS-2026 marked. The maximum temperature rise should not exced 45 degree celsius in HV/LV winding when measured by resistance method after continuous full load run on an ambient temp of 50 degree celsius and shall comprise of the following:-

a) Three Nos porcelain bushing suitable for 33 KV on HV side, complete with copper rods, nuts and washers and arching horns. (b) four Nos porcelain bushing suitable for 11 KV on LV side, complete with copper rods, nuts and washers with cable end box. (c) Monogram plate. (d) Detachable cooling radiators with drain & air release plug, isolating valves and lifting lug at top & bottom. (e) Oil conservator with filter and drain plug. (f) Prismatic/transparent oil gauge. (g) De-hydrating breather with first fill of dehydrating agent (silica gel). (h) Pressure relief valve with alarm/trip contacts. (j) Thermometer pocket. (k) Air release plug. (l) Inspection cover (m) Lifting lugs for complete transformer (n) Top cover lifting lugs (o) Jacking lugs (p) Top filter valve

(q) Instruction plate (r) Drain cum bottom filter valves (s) Earthing terminal and stud (t) Off load tap changer with locking arrangement. (u) Rating and Diagram plate (v) Bucholz relay with alarm & trip contacts. (w) Bi directional roller wheel -04 Nos (x) Marshalling box for termination of all alarm & trip controls of the transformer. (y) OTI (Oil temperature indicator) & WTI (Winding temperature indicator) with alarm & trip contact on HV and LV both side. (z) Magnetic oil level gauge with alarm and trip contacts. (aa) Oil surge relay. (ab) Shut off valve for bucholz relay. (ac) Oil temperature indicator dial type of 150 mm with alarm and trip contact capillary type. (ad) Two earthing terminals on tank cover to facilitate fixing of 50x6 mm galvanised iron earth strip for earthing of body. (ae) First filling of new and unused transformer oil, IS-335 marked (Make Savita/Apar/Power Link filtered and tested upto 60 KV dielectric strength of 2.5 mm air gap between testing electrodes.

Note : (i) Transformer shall be supplied inclusive of initial fill of insulation oil confirming to IS-335 and of dielectric strength not less than 60 KV as per IS-1866. (ii) Installation of the transformer shall be carried out as per IS-10028. (iii) Commissioning of the transformer shall be carried out by the rep of OEM after configuration of trip setting of the existing 33 KV VCB provided in the transformer bay for its protection as per the fault level of the proposed power transformer (iv) Configuration of all trip/Alarm signals of the transformer with the existing auxillary relays of relay control panel. Control cables armoured and copper conductor of suitable size & core to be provided from marshalling box to relay control panel and is included in the quoted rates of transformer. Simulation check for every alarm/trip contact to eb carried by rep of OEM for getting the signal at the auxillary relays of relay control panel. Any unserviceable auxillary relay is to replaced without any additional cost.

Earthing complete with galavanized steel earth electrode 600x600x6.3 mm thick, buried directly in ground (earth pit not less than 2.25 meters deep below ground level) with top edge of the plate not less than 1.5 meters below normal ground level, connected to GI strip of size 32 x 6 mm by means of bolts, nuts, check nuts and washers of galvanised iron or steel all as shown in electrical plate No-3 connected to earthing test point all as specified or indicated including testing on completion including PCC pit type C-1 (1:3:6) in cement concrete & 40 mm thick precast RCC cover in (1:2:4) type B-1 reinforced with 8 mm dia MS round bar @ 75 c/c both ways with 02 Nos lifting handles of 12 mm dia MS plain bar, GI pipe 20 mm dia light grade with funnels & wire mesh for watering and 50 mm dia light grade GI pipe for earth lead protection etc including necessary earth work and excavation complete all as specified and directed. Note:- Quantity of GI earth lead & protection pipe upto 7.5mtrs long shall be deemed included in the rate quoted and beyond 7.5 m shall be measured separately.

All as per item No 2 here - in - before but using copper plate 60×60cm ×3.15mm thick electrode and 20×3mm copper strip asearthing lead.

Material and labour for earth continuity conductor or main earthing lead fixed to wall on porcelin insulators or recessed or chases or burried in ground or drawn in conduit / pipe or fixed to poles or any other indidcated situation for loop earthing etc as requid 50x6 mm galvanised iron strip all as specified and as directed.

All as per item No 4 here - in - before but 50x6 mm copper strip.

Supply, lay & test cable XLPE insulated screened PVC bedded, galvanized steel strip or wire armoured, electric power cables (heavy duty) with stranded aluminium conductor, 11000 volts (Earthed) grade, of size 3 core 185 Sqmm.

Supplying, jointing, testing and commissioning of cable jointing kit for 11 KV(Earthed) grade cable for outdoor termination heat shrink type joint complete with jointing material and accessories suitable for 3 core XLPE armoured aluminium conductor cable of size 120 sqmm to 185 sqmm complete all as specified and as directed.

Paragon Electrotechnics

nhsaluji and associates