supply, installation, testing & commissioning of outdoor, plinth mounted, oil immersed, non- sealed type ( transformer tank body & cover are bolted ) distribution transformer, 500kva rating, 11kv / 415v, 3-phase, 50 hz, primary winding in delta and secondary winding in star ( vector symbol - dyn-11 ) , onan cooled, off-load tap changer for variation of hv voltage from +5% to -10% in steps of 2.5%, with all standard fittings as per clause 20.1 of is 1180 ( part-1 ) and oil temperature indicator & winding temperature indicators, drain-cum-sampling valve ( 3 / 4 nominal size thread is:554 ) of steel with plug, energy efficiency level-3 & above, conforming to is 1180 ( part.1 ) :2014 with amendment no.1, 2, 3 & 4. following has to be submitted along with supply of materials: i ) type test report as per is:1180 ( part 1 ) of transformer having same rating, make ( & model if any ) and design from nabl accredited lab. ii ) routine test certificates as per is:1180 ( part 1 ) . iii ) special test certificates as per clause 21.4 sl. no. ( a ) , ( c ) , ( d ) & ( e ) of is:1180 ( part 1 ) . only oem should supply this material along with its past credibility in govt. organizations. the transformer shall be make of power master, aeg, emco, bhel, power star or any other reputed / railway approved brand. tc & gc as per irs terms& conditions should be supplyalong with the material. [ warranty period: 30 months after the date of delivery ]