Isolating transformers and safety isolating transformers - Requirements

Applies to stationary or portable, single-phase or polyphase, air-cooled isolating and safety isolating transformers, associated or otherwise, having a rated supply voltage not exceeding 1000 V alternating current and 1000 V unsmoothed direct current and rated frequency not exceeding 500 Hz. Has the status of a group safety publication in accordance with IEC Guide 104.