supply of supply of outdoor type , plinth mounted, distribution transformer , supply of outdoor type , plinth mounted, distribution transformer, minimum energy efficiency level 3 of rating 250 kva, 3-phase, 11kv/415-240v,50hz, oil immersed, non-sealed type (transf ormer tank body and cover are bolted), copper wound, primary winding in delta and secondary winding in star (vector symbol- dyn11), onan cooled transformer, conforming to is 1180 (part1):2014 with amendm ent 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-cumsampling valve. oil temperature indicator & winding temperature indi cators will be provided as per clause 20.2 f) of is 1180 (part 1). terminal arrangement: the transformers sh all be fitted on high voltage and low voltage sides bushing appropriate voltage and current ratings., low vo tage side cable end box required. the high voltage bushings (3 nos.) shall conform to is/iec 60137. the lo w voltage bushings (4 nos.) shall conform to is 7421. off-circuit tap changer (applicable for all ratings abo ve 200 kva) for variation of hv voltage from +5% to -10% in steps of 2.5%. following has to be submitted by supplier along with supply of material: (i) type test report of transformer having same rating, make (& model if any) and design from nabl accredited lab as per is: 1180 (part 1) latest. (ii) routine test certificat es as per is: 1180 (part 1) latest. (iii) special test certificates as per clause 21.4 sl. no. (a), (c), (d) & (e) of is:1180 (part 1) latest. [ warranty period: 30 months after the date of delivery ] ]