This standard applies to insulator strings and sets comprising string insulator units of ceramic material, glass or composite material for use on a.c. overhead lines and traction lines with a nominal voltage above 1 000 V and a frequency between 15 Hz and 100 Hz.
This standard also applies to insulator strings or sets of similar design used in substations.
This standard establishes a standard test procedure for power arc tests on insulator sets. It also establishes a standard test procedure for power arc tests on short strings.