This part 2 of IEC 61558 applies to stationary or portable, single-phase or polyphase, air-cooled safety isolating transformers, associated or otherwise. It has the status of a group safety publication in accordance with IEC Guide 104 This part 2 supplements or modifies the corresponding clauses in IEC 61558-1, This Standard replaces Chapter III, Section 1 of IEC 60742.