| 2 | Supply, installing, testing and commissioning of outdoor type plinth mounted step down transformer, 11 KV/433 Volts (at no load), Level -II, AC 3 phase 50 Hz, 630 KVA capacity, core type, double copper wound, oil immersed, naturally cooled, Oil Natural-Air Natural (ON AN), with external cooling tubes, delta connected on primary side (HV) and star connected on secondary side (LV) in accordance with vector group DYN-11 with Neutral brought out on secondary side (LV side) and having tapings at +5% to -10% in steps of 2.5% on HV side to be changed by means of hand operated off load tap changer gear. The maximum temperature rise should not exceed 40 degree celsius in oil and 45 degree celsius in HV/LV winding when measured by resistance method after continuous full load run on an ambient temp of 40 degree celsius. The transformer shall be of BOLTLESS core design. Transformer shall be double wound, core type with low loss, non ageing, high permeability PRIME GRADE, CRGO with M4 Grade or Better, perfectly insulated and clamped to minimize noise and vibrations. The transformer shall be IS 1180 (Part-I) : 2014 and shall comprise of the following :-
(a) One cable box on HT side (primary side) consisting of three nos porcelain bushing with copper rods, complete with nuts and washers, with cable glands suitable for reception / taking out 3 core 120 Sq mm, HT 11000 volts grade, XLPE insulated and PVC sheathed, heavy duty, armoured cables including jointing materials complete.
(b) One cable box on LT side (Secondary side) consisting of four nos porcelain bushing with copper rods, complete
with nuts and washers, with cable glands.
(c) Oil conservator with filter type drain valve and oil level guage.
(d) De-hydrating breather with first filling of dehydrating agent (silica gel).
(e) Explosive vent, Thermometer pocket on tank cover, Oil level gauge, Oil drain filter valve, Lifting lugs, Oil filling
hole with cap / plug with connection plate complete, Airrelease valve plug and four nos plain solid cast steel
detachable rollers.
(f) One number 100 mm dia, dial type thermometer, vapour pressure type, having range 0-120 degree celsius with metal guard having maximum perimeter temperature reading indicator with re-setting device.
(g) Two earthing terminals on tank cover to facilitate fixing of 50 x 6 mm galvanised iron earth strip for earthing of body.
(h) Rating plate and terminal marking plate.
(j) Extra bushing for neutral, in the LT cable box for providing independent set of ething for neutral.
(k) First filling of new and unused transformer oil, IS-335 marked, filtered and tested upto 60 KV dielectric strength at 2.5mm air gap between testing electrodes
(l) Providing adequate size and nos of channels, embeded in floor, for movement of transformer.
(m) Unidirectional roller wheel.
(n) Other accessories as per manufacturer design.
(o) Oil temperature indicator, winding temperature indicator, marshling box single window, double flit buchhloz relay with alarm and trip contact.
Note : Transformer shall be supplied inclusive of initial oil filling to appropriate level of insulation oil with desired dielectric strength. Cost of Provn of plinth for transformer as per OEM drawing shall be deemed to be included in the cost quoted by the bidders and nothing extra shall be admissible. | 1 | Each |
