Epoxy Resin Insulator Measurement Method

For the multi-component combination high voltage standoff insulators, the insulation resistance of high voltage epoxy can be measured with power off or with power on. The method is to connect a high resistor to the live epoxy resin insulator, so that the megohmmeter measuring the insulation resistance is at ground potential, and subtract the resistance value of the high resistor from the measured insulation resistance, which is the insulation resistance value of the measured high voltage epoxy resin. The principle wiring for measuring the insulation resistance of high voltage standoff with power on is shown in Figure 4-1. In Figure 4-1, R is the resistor in the high resistance rod, the resistance value is selected according to 10~20kΩ/V, the length is selected according to 0.5~105kV/cm, and the resistance capacity per unit is 1~2W; C is the grounding capacitor, which can make the megohmmeter at ground potential. The insulation resistance of C should reach the maximum limit of the megohmmeter to ensure the accuracy of the measurement. The capacitance of C is 0.01~0.05μF, and it should be able to withstand a DC voltage of more than 3000V.