FXBW4-66 / 70 composite suspension insulator insulator type structure height H.mm minimum arc distance L.mm minimum nominal creepage distance mm full-wave lightning impulse withstand voltage kV (peak value) of not less than impulse wet withstand voltage kV (peak ) Not less than power frequency withstand voltage kV (rms) of not less than wet FXBW1-66 / 70 880 ± 15 700 1450 410 - 200 185 FXBW2-66 / 70 940 ± 15 760 1450 410 - 200 185 FXBW3-66 / 70 880 ± 15 700 1900 410 - 200 185 FXBW4-66 / 70 940 ± 15 760 1900 410 - 200 185