IEC 61000-4-28:1999+A1:2001+A2:2009 establishes a reference for evaluating the immunity of electric and electronic equipment when subjected to variations of the 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). Therefore, no need to order amendments in addition to this publication.