NF C63-421:1994 LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES. PART 1 : TYPE-TESTED AND PARTIALLY TYPE-TESTED ASSEMBLIES. (EUROPEAN STANDARD EN 60 439-1).
1994NF C63-421:1994 LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES. PART 1 : TYPE-TESTED AND PARTIALLY TYPE-TESTED ASSEMBLIES. (EUROPEAN STANDARD EN 60 439-1).