Oil cooling unit for transformer/ Converter including motor. Spec./ Drg. No.- as ( 1 ) Oil cooling unit for transformer/ Converter with aluminium impeller and casing relevant Drg. No.- CLW/ ES/ 3/ 0647 Alt.- E and latest. ( 2 ) 30 KW motor for cooling unit ( Centrifugal design ) as per RDSO Spec. No.- E- 10/ 3/ 09 ( motor ) with amendment 1 to 6.