Provides recommendations for the selection and application of surgearresters to be used in three-phase systems with nominal voltagesabove 1kV. It applies to non-linear resistor type gapped surgearresters as defined in IEC 60099-1 and to gapless metal-oxide surgearresters as defined in IEC 60099-4.The contents of the corrigendum of April 1996 have been included in this copy.