IEC 60255-8 Ed. 2.0 b:1990, Electrical relays - Part 8: Thermal electrical relays

This edition supersedes the first edition of IEC 60255-8 (1978) and IEC 60255-17 (1982). Applies to dependent specified time electrical measuring relays which protect equipment from electrical thermal damage by the measurement of current flowing in protected equipment. States the particular requirements for thermal electrical relays. Is to be read in conjunction with higher level documents in the IEC 60255 series.