PROVN OF NGR FOR TRANSFORMER AT MRS AND ALLIED WORKS AT AF STN HALWARA UNDER GE (AF) HALWARA

Supply, installation, testing & commissioning of stainless steel (AISI-304) Punch Grid type NGR (NEUTRAL GROUND RESISTOR) housed in 2mm thick sheet enclosure powder coated with shade RAL-7032 for 5 MVA 66/11 KV Transformerhaving following brief technical particulars: Rated Voltage - 11 KV, Rated Resistance - 63.5 Ohm (+/- 10 %), Rated current- 100 Amp, Time Rating - 10 Sec, Temp Rise - 350 deg C above 50 deg C Ambient, Location, DOP - Outdoor, IP55, Reference Std. - IEEE-32, with (Neutral Termination) 1 No. 12 KV Class, Brown glazed Porcelain Bushing fitted with M12 brass/SS Stud, with (Ground Termination) 1 No. 12 KV class, Brown Glazed Porcelain bushing Fitted with M12 Brass/SS Stud Complete all as specified and directed by Engr-in-charge. Accessories:- (1) Thermostat with Space Heater (2) NGR Monitoring Relay- M79N (3) Sensing Resistor-SR1000 (4) MCT (5) PT Note:- (i) The rate quoted by contractor is deemed to be inclusive of escavation, PCC and foundation required for NGR. Decision of GE shall be final regarding type of PCC and foundation details. Contractor is requested to visit GE office before quoting to understand the scope of work. (ii) Control wire and cable required for connection is deemed to be included rate quoted by contrctor.

Supplying, laying, jointing, testing and commissioning of HT XLPE insulated, screened, PVC bedded, galvanised steel strip or wire armoured, electric power cables (heavy duty) with aluminium conductor, 11000 volts Earthed grade cross sectional area 120 Sqmm, Single core laid in trenches /pipes /ducts /along poles/ walls/ equipment etc with and including jointing kit for both end connection of 03 Nos x Power Transformers & NGR and thimbles/lugs of suitable size for coonection of cable complete all as specified and directed by Engr-in-charge.

Material & Labour for earthing complete with galavanised steel plate electrode 600 x 600 x 6 mm thick burried directly in ground vertically (earth plate to a depth of not less than 2.25 meter deep below ground level) with the top edge of earth plate at a depth of not less than 1.5 meter below normal ground level connected to GI strip 32x6mm by means of bolts, nuts, washers of galvanised iron and provision of earth wire, galvanised iron protection pipe 40mm bore, light grade up to and including test point with and including necessary earth work in any type of soil and PCC (1:3:6) type C1 (using 20mm graded stone aggregate) earth chamber, watering pipe 20mm dia galvanised iron light grade with funnel, RCC (1:2:4) type B1 precast cover 40mm thick with 6mm dia mild steel bars complete all as shown in electrical plate N.3 of SSR part-I connected to earthing test point all as specified or indicated,including taking down and testing on completion and directed by Engr-in-charge. Note:- Quoted rate deemed to include the cost of excavation and earth work, PCC pit, funnel and cover etc required for stability completion of work.

Material & Labour for chemical Earthing Electrode using M.S pipes, Outer Dia is 76 mm with a wall thickness of 1.6 mm, Inner Dia is 42 mm with a wall thickness of 2.6 mm, Over all Length is 3000 mm . A groundbreaking corrosion resistant Crystalline Conductive Compund is filled and compacted in the cavity within the pipes to enhance the electrodes performance. Conforming to IS : 3043 - 1987 i.e., Code of Practice For Earthing, (Tolerance : Dia: ± ı.o mm Wall) Thickness: ± 0.2 mm, Length: ± 20 mm). Back Fill Compound(s) , Carbon based, high conductive material, Resistivity : < 0.5 ohm-metre (In dry conditions), Resistivity is not moisture dependant, Ph Value : 6.5 - 8.0, Electronic & Ionic conduction, Less susceptible to shrinkage, Maintenance Free, Excellent bonding properties, Enhances electrode size, Packing Size : 25 kilograms, Recommended for harsh conditions incl Poly Plastic Earth pit Chamber Cover Heavy Duty (3 ton Capacity) including laying of copper strip from Earth pit to testing point and testing point to equipment alongwith necessary brasing copper rod with copper strip and including the earthing strip to be covered in HDPE pipe of size 50mm fixed on wall using suitable bracket for proper insulation amongst the earthing rods to test point as well as from test point to equipment Complete all as specified and directed by Engr-in-charge. Note : Earth test value required below one ohms, if not found satisfactorily result the contractor will be liable to provide extra materials required for achiveing the earth value less than one ohm. No extra cost will be given to the contractor. In case contractor fails to achieve the desired values no payment will be admissible for the item.

Supply & Fixing galvanised iron strip 32 x 6 mm with porcealian shaddles and fixing screws for roof conductors and screwed including 3 Nos, 8 mm dia 25mm long hex head scews for lighting conductor complete all as specified and directed by Engr-in-charge.

Supply & Fixing copper strip 20 x 3.15 mm with PVC shaddles and fixing screws for roof conductors and down conductors and welding/brazing of joints above ground complete all as specified and directed by Engr-in-charge.