XHP5-70 146 280 400 16 90 50 42 120 135 120 ≈20 35 52.5 70 6.7 Main dimensions mm Type frequency voltage kV rms no less than full-wave lightning impulse voltage kV peak pressure of not less than the increase rate% flashover tensile mechanical load kN Weight kg structural height H disc diameter D nominal creepage distance L connection type labeled stem wet flashover flashover 1min wet withstand 50% flashover breakdown tolerance test routine test lh electromechanical electromechanical destruction not less than XHP5-70 bell insulator tolerance insulators long run experiencing strong electric field, natural erosion, the role of complex mechanical stress and other factors, will inevitably aging. Under the same electrical operating conditions near the wire side of the insulator and insulator insulators and other locations near the ground potential side insulating properties compared prone to aging. Usually salinity affected areas insulating characteristics aging rate of about 0.6 percent, but Kranjcar Han Salt Lake potassium and magnesium salt deposit area comprehensive aging rate of insulation properties of up to 1.3% after 5 years.