This standard prescribes insulation levels and dielectric test requirements for power transformers where: (1) The transformer insulation levels and dielectric test requirements are explicitly specified to be in accordance with this standard (2) The transformers are to be operated at system voltages from 115kV through 230 kV (3) The transformer has a rating@either single-phase or three-phase@ equal to or greater than 30 000 k V A self-cooled or 50 000 k V A forced-cooled These requirements@ when specified@ supersede all requirements relative to insulation levels@ dielectric tests as contained in ANSI/IEEE C571200-1980 [4]1 and ANSI/IEEE C571290-1980 [5]. Unless explicitly specified@ this standard shall be considered as excluded in the event of any blanket reference to all current standards. 1 The numbers in brackets correspond to the references listed in Section 2 of this standard.