Cap and Pin Type Insulator: ANSI Standard Insulator: 55-1,55-2,55-3,55-4,55 ... Average/lb (kN)3,000(13.3)2,500(11.1)Average Flashover VoltageLow-frequencyDry/kV35355045Wet/kV20202525Critical-impulsePositive/kV50507570Negative ... 6(152)Cantilever Strength/Average/lb (kN)2,500(11)3,000(13)3,000(13)Average Flashover VoltageLow- ... 1-3/4 inches. LOW AND MEDIUM VOLTAGE PIN TYPE INSULATOR(ANSI STANDARD)