supply of 250 kva,11kv/415 v step down indoor type , 250 kva,11kv/415 v step down indoor type floor mounted distribution transformer 3 phase 5 0 hz oil immersed naturally cooled (onan)core type double wound with copper conductor off circuit tap ch anger in 5 step, high voltage connected in delta whereas low voltage side connected in star having vector g rouping dyn 11 with neutral of secondary winding through out for earthing maximum current density shoul d be 2.5 amp sq.mm .maximum flux density 1.6 tesla having cable boxed on high voltage and low voltage sides complete with transformer configuring on is:2026/1977 part 1 and first feeling of oil as per is:355, m ake mirzapur elect. industries ltd, abb transformer or similar [ warranty period: 30 months after the date of delivery ] ]