FXBW4-10 / 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 FXBW4-10 / 70 310 ± 15 130 350 75 - 47 42