SPECIAL REPAIRS FOR STANDBY TROLLY MOUNTED SPARE TRANSFORMERS UNDER GE (NORTH) SANTACRUZ AT MUMBAI

Amount

Supplying, installing, testing and commissioning of AC 3 phase, 50 HZ, 315 KVA capacity transformer (Trolly mounted type), step down, outdoor type, 11000/433 volts (at no load) with system voltage 12KV all as per IS 1180 (Part 1):2014, copper wound, oil immersed, naturally cooled with external cooling tubes, ONAN Cooling, core type, delta connected on primary (HV) side and star connected on secondary (LV) side in accordance with vector symbol DYN-11 (vector group-4) with neutral brought on secondary (LV) side & having tappings in equal steps of 2.5 % from (+) 5% to (-) 10% on primary side by means of hand operated off load tap changing gear, so as to change/correct L.T voltage on secondary side including provision of all necessary / standard fittings all as per IS:2026 & IEC 76 Latest ammendments and confirming to BEE 5 Star Rating (Level 3 transfomer) as per IS 1180 (Part 1):2014 (a) The core shall be stack/wound type of high grade Cold Rolled Grain Oriented or Amorphous Core annealed steel lamination having low loss and good grain properties, coated with hot oil proof Inter layer insulation of Nomex /Epoxy dotted Kraft Paper, bolted together and to the frames firmly to prevent vibration or noise. The core shall be stress relieved by annealing under inert atmosphere if required.The complete design of core must ensure permanency of the core loss with continuous working of the transformers. LV winding shall be such that neutral formation will be at top. Current density for HV and LV winding should not be more than 2.8 Ampere per sq mm. (b)The maximum allowable losses at 75 °C for 11/0.433 kV at 50% of rated load and total losses at 100% of rated load shall not exceed the maximum total loss 416 watts and 1281 watts respectively without any positive tolerance all as per specified in IS 1180 (Part-1):2014 for energy efficient rating 5star. (c) Overload capacity of transformers shall be suitable for loading as per IS 6600. (d) The percentage impedance of transformers at 75 °C for 315 kVA shall be as per Table 6 of IS 1180 (Part-1) : 2014 (e) Transformer tank construction shall conform in all respect to clause 15 of IS 1180(Part-1):2014. The internal clearance of tank shall be such, that it shall facilitate easy lifting of core with coils from the tank without dismantling LV bushings. All joints of tank and fittings shall be oil tight and no bulging should occur during service. Inside of tank shall be painted with varnish/hot oil resistant paint. The top cover of the tank shall be slightly sloping to drain rain water. The tank plate and the lifting lugs shall be of such strength that the complete transformer filled with oil may be lifted by means of lifting shackle. Manufacturer should carry out all welding operations as per the relevant ASME standards. The transformer tank shall be of robust construction and shall be built up of electrically tested welded mild steel plates of thickness of 6 mm for the bottom and top and not less than 4 mm for the sides for distribution transformers with Tolerances as per IS-1852.The space above oil level in the tank shall be filled with dry air or nitrogen conforming to commercial grade of IS 1747. The tank shall further be capable of withstanding a pressure of 0.8kg/sq.cm and a vacuum of 0.7 kg/sq.cm (g) without any deformation.

(f) Audible sound levels for 315KVA, 50Hz liquid immersed distribution transformers shall be 56 decibels (NEMA Standards) (g) One cable box on primary H.V side having cable glands suitable for 95 Sqmm 3 core XLPE 11 KV H.T cable consisting of 3 Nos porcelain H.T bushings with brass/ gun metal bushing rods confirming to IS 2099 and IS 3347 for outdoor bushing complete with nuts and washers. HT Cable box should prevent the ingress of moisture into the box due to rain water directly falling on the box. The cable box on HT side shall be of the split type with faces plain and machined and fitted with Neo-k-Tex or similar quality gasket and complete with brass wiping gland to be mounted on separate split type gland plate with nut-bolt arrangement and MS earthing clamp. The bushings of the cable box shall be fitted with nuts and stem to take the cable cores without bending them. The stem shall be of copper with copper nuts. The cross section of the connecting rods shall be stated and shall be adequate for carrying the rated currents. On the HV side the terminal rod shall have a diameter TS for 3 Phase DT 11 of not less than 12 mm. The material of connecting rod shall be copper. HT Cable support clamp should be provided to avoid tension due to cable weight. (h) One cable box on secondary (LV) side consisting of 4 Nos porcelain bushings complying to IS 7421 with GM bushing rods complete with GM nuts, and washers with cable gland suitable for reception of outgoing L.T. PVC sheathed armoured cables having non-magnetic material gland plate with appropriate sized single compression brass glands on LV side to terminate 1.1 kV/single core XLPE armoured cable. (j) The bushing rods and nuts shall be made of brass material 12 mm diameter for both HT and LT bushings. The bushings shall be fixed to the transformers on side with straight pockets and in the same plane or the top cover . The tests as per latest IS 2099 and IS 7421 shall be conducted on the transformer bushings. (k) OIL CONSERVATOR: The provision of conservator is mandatory with oil gauge, air release plug and breathing device with a drain plug and a filling hole 32 mm (1¼”) normal size thread with cover. The dehydrating agent shall be silica gel. The moisture absorption shall be indicated by a change in the colour of the silica gel crystals which should be easily visible from a distance. Volume of breather shall be suitable for1Kg of silica gel conforming to IS 3401. The total volume of conservator shall be such as to contain 10% quantity of the oil. Normally 3% quantity the oil shall be contained in the conservator. (l) The radiators can be tube type or fin type or pressed steel type to achieve the desired cooling to limit the specified temperature rise. (m) Transformer to be painted with poly urethene/powder caoted (color light gray & DA gray) paints over anti corrosive primer & shall be free from runs, sags, wrinkles, patchiness, brush marks or other defects. All primers shall be well marked into the surface, particularly in areas where painting is evident and the first priming coat shall be applied as soon as possible after cleaning. The paint shall be applied by airless spray.

(n) One No 100 mm dia dial type thermometer vapour pressure type having range 0-120 degree centigrade with temp reading pointer, max temp indicator and resetting device. (o) Rating plate with terninal markings. (q) Two earthing terminals on tank/tank cover to facilitate fixing of 32 x 6 m GI earth strip. (r) Lifting lugs. (s) Four plane solid cast steel detachable rollers. (t) First fill of fresh transformer oil conforming to IS-335, BS148, D-1473, D-1533-1934IEC Pub296 and tested upto 40 KV dielectric strength. Use of recycled oil is not acceptable. The specific resistance of the oil shall not be less than 2.5X10¹² ohm-cm at 27°C when tested as per IS 6103. (u) Extra bushing for neutral outside the L.T cable box for providing independent earthing for neutral. (v) Provision of 2 Nos danger boards 250 x 200 mm size made out of 1.6 mm thick M.S. plate, vitreous enameled white, with letters. figures of voltage and conventional skull and bones in signal red colour , one at H.T side and other on L.T side. (w) Any other fittings / accessories so as to conform the whole transformer to IS 1180 (Part 1): 2014. (x) The DistributionTransformers to be supplied against this Specification shall be suitable for satisfactory continuous operation under the following climatic conditions as per IS 2026(Part-I): (i) Location : Mumbai (ii) Maximum ambient air temperature (°C) : 40 °C (iii) Minimum ambient air temperature (°C) : 10 °C (iv) Maximum average daily ambient air temperature (°C) : 33 °C (v) Maximum yearly weighted average ambient temperature (°C) : 32 °C The temperature rise over ambient shall not exceed the limits given below: (i) Top oil temperature rise measured by thermometer : 35 °C (ii) Winding temperature rise measured by resistance method : 40 °C

Material and labour for factory made trolley for transformer of size 2.8 x 2.5 Mtr made out of mild steel angle/ chanels medium weight beams & MS flates withj necessary welding in any postion driliing in hot/cold etc for longitude and cross members of trolly made out of ISMC chanel 100 and top of the members coverd with 6 mm thick MS plate plateform and vertical support over the plateform with MS equal angle of size 50 x 50 x 6 mm thick angles with MS flate 50 x 5 mm thick for two runs of bracing the supports, V type towing frame with hook with spring and check nuts and mounting bracket with bush for movement of tow assembly. The assembly made out of ISMC chanel 100 with long and cross member, turning plate assembly for front wheel only fitted in front axle, the front and rear axle made out of medium weight beam ISMB 100 including tyre with tube F78-15 8 play rataing four nos with wheel drum, mounting bracket, bearings, check nuts, locknuts, key etc welded with medium beam with nut bolts washers as required for mounting the transformer and other fixing arrangement for proper toeing with Eicher vehicle and supporting legs 04 nos with necessary screw jack system for static support on steady position complete all as directed.

Supply, laying & testing XLPE insulated screened PVC bedded, galvanized steel strip or wire armored, electric power cables (heavy duty) with stranded aluminum conductor, 11000 volts grade, of size 95 sqmm, 3 core complete all as specified and directed by Enge-in-charge.

S&F Cable jointing kit for 11 KV (Earthed) grade cable for indoor termination heat shrink type joint complete with jointing material and accessories suitable for 3 core XLPE armoured aluminium conductor cable of size 95 sqmm complete.

S&F 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 95 sqmm complete.

sapana enterprises (BID ID -3466689)

MONA GENERATOR SEVICES PVT. LTD. (BID ID -3463623)