Historical
IEC 60305 Ed. 4.0 b:1995
Insulators for overhead lines with a nominal voltage above 1000 V - Ceramic or glass insulator units for a.c. systems - Characteristics of insulator units of the cap and pin type
Applies to string insulator units of the cap and pin type with insulating parts of ceramic material or glass, intended for a.c. overhead lines with a nominal voltage greater than 1 000 V and a frequency not greater than 100 Hz and to insulators of similar design used in substations.
International Electrotechnical Commission [iec]

