supply, installation, commissioning and testing complete with all accessories of transformer of 33 kv capacity 200 kva step down, outdoor floor mounted, double copper wound,3 phase, 50 hz, ac, oil immersed, onaf confirming to is-2026 and iec62770 including external cooling tubes/radiator cores type having voltage ratio 33000/433 volts (corresponding to principal tapping) winding delta connecting on primary side (hv side) and star connected on secondary side (lv side) in accordance with vector symbol dyn11 (vector group) with neutral brought out on lv side and looping on hv side for contact output so as to alter/vary secondary voltage by (+) 5 to (-) 15 in equal steps of 1.25 to be changed by tap changer. 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, core shall be purchased directly from manufacturer of core or from their accredited marketing network and not through any agent. before placing order for procurement of transformer, the contractor shall submit the credentials in respect of the manufacturer of core and transformer shall be procured only after approval from ge in respect of name of manufacturer of transformer as well as manufacturer of core. the limit of termperature rise after continous full load runs as specified in is/iec 60076 shall be suitably adjusted to suit the ambient temperature of maximum 50 degree celsius prevailing at site all as specified and directed including having following characteristics :-
make :- voltamp limited / urja techniques india pvt ltd/indian transformers electricals
(a) the transformer shall confirm to the latest edition of applicable standard as follows :-
(i) is-2026 for tests and tolerance of guarnteed particulars.
(ii) is-3639 for fitting and accessories.
(iii) is-2099 for bushing >1000v.
(iv) is-7421 for bushing <1000 v
(v) is-1271 for electrical insulation classified by thermal stability.
