This European Standard gives Ecodesign requirements for small power transformers complying with EN 61558 series and in relation to Commission regulation (EU) N° 548/2014 implementing the European Directive 2009/125/EC. This standard is applicable to transformers with 50 Hz AC input and output with a rated power of 1 kVA or more and a voltage lower than 1 kV, except those excluded in the regulation. For transformers with a voltage between 1 kV and 1,1 kV, this standard may be used as a guide.