supply of 250kva outdoor transformer:- 250 kva, 6kv / 415v, 3-phase, 50hz, outdoor type distribution transformer., supply of outdoor plinth mounted distribution transformer of rating 250 kva, 6kv / 415v, 3-phase, 50hz, oil immersed, non-sealed type ( transformer tank body and cover are bolted ) , primary winding in delta and secondary winding in star ( vector symbol- dyn11 ) , onan cooled transformer, energy efficiency level ( latest ) -2 & above, conforming to is 1180 ( part 1 ) :2014 with amendment nos. 1, 2, 3, 4 or latest, and supplied with all standard fittings mentioned in clause 20.1 of is 1180 ( part 1 ) latest with condition that drain-cum-sampling valve will be applicable. oil temperature indicator & winding temperature indicators will be provided as per clause 20.2 f ) of is 1180 ( part 1 ) . terminal arrangement: the transformers shall be fitted on high voltage and low voltage sides with outdoor type bushings of appropriate voltage and current ratings. the high voltage bushings ( 3 nos. ) shall conform to is / iec 60137. the low voltage bushings ( 4 nos. ) shall conform to is 7421. suitable cable-end box along with cable entry hole glands is to be provided at lt side . the type of tap changer: details as per is: off-circuit tap changer for variation of hv voltage from + 5% to -10% in steps of 2.5%. [ warranty period: 30 months after the date of delivery ]