IEC 61000-4-28 is entitled “Electromagnetic compatibility (EMC) – Part 4-28: Testing and measurement techniques – Variation of power frequency, immunity test for equipment with input current not exceeding 16 A per phase.” This standard establishes a reference for evaluating the immunity of electric and electronic equipment when subjected to variations of power frequency. Only conducted phenomena are considered, including immunity tests for equipment connected to public and industrial networks. This consolidated version consists of the first edition (1999), its amendment 1 (2001), and its amendment 2 (2009). There is, therefore, no need to order amendments in addition to this publication.For more information, or to order this standard, go to the International Electrotechnical Commission website.