This Standard applies to power transformers complying with the series of publications IEC 60076. It is intended to provide information to users about: - certain fundamental service characteristics of different transformer connections and magnetic circuit designs, with particular reference to zero-sequence phenomena; - system fault currents in transformers with YNynd and similar connections; - parallel operation of transformers, calculation of voltage drop or rise under load, and calculation of load loss for three-winding load combinations; - selection of rated quantities and tapping quantities at the time of purchase, based on prospective loading cases; - a