A basic EMC (electromagnetic compatibility) publication, which considers immunity tests for electronic and electric equipment in its electromagnetic environment. Considers only conducted phenomena, including immunity tests for equipment connected to industrial and public networks. The objective is to establish a reference to evaluate the immunity of electronic and electric equipment when subjected to power frequency variations. Applicable to electronic/electric equipment connected to a 50 Hz or 60 Hz distributed network with rated line current up to 16 A per phase, and does not cover electronic/electric equipment that is connected to a.c. 400 Hz distribution networks.