EVS-EN 61558-1:2001

This International Standard deals with all aspects of safety (such as electrical, thermal and mechanical) of: a) Stationary or portable, single-phase or polyphase, air-cooled (natural or forced) isolating and safety isolating transformers, associated or otherwise, having a rated supply voltage not exceeding 1000 V a.c. and rated frequency not exceeding 1 MHz, the rated output not exceeding: For isolating transformers: - 25 kVA for single-phase transformers, 40 kVA for polyphase transformers. For safety isolating transformers: - 10 kVA for single-phase transformers, 16 kVA for polyphase transformers.