EN 61558-2-1:1997 Safety of Power Transformers@ Power Supply Units and Similar Part 2-1: Particular Requirements for Separating Transformers for General Use
2007EN 61558-2-1:2007 Safety of power transformers, power supplies, reactors and similar products - Part 2-1: Particular requirements and tests for separating transformers and power supplies incorporating separating transformers for general applications (Remains Current)
1997EN 61558-2-1:1997 Safety of Power Transformers@ Power Supply Units and Similar Part 2-1: Particular Requirements for Separating Transformers for General Use