Porcelain insulators Measurement

For insulator unit member, can only measure in case of power failure of the insulation resistance, the relevant provisions of the statutes, and the use of more than 2500V megger. We are currently using more 2500V and 5000V megger, also have higher voltage specialized equipment. But in fact, less than 1 * 104MΩ, the same precision 2500V and 5000V megger at the same humidity measurement of the insulation resistance is basically the same. In the measured insulation resistance greater than 1 * 104MΩ when, 2500V megger can not be read accurately insulation resistance value, can only count ∞. The 5000 Megohmmeter is desirable maximum insulation resistance of up to 2 * 105MΩ.

For multi-component combination of insulator, may be power outages can also be charged measure the insulation resistance. The method is the high resistor connected to the charged insulator, the measurement of the insulation resistance megger at ground potential, the high resistance of the resistance value is subtracted from the measured insulation resistance, the insulation resistance value is measured insulator. Insulator insulation resistance measurements on live wiring schematic shown in Figure 4-1. Figure 4-1, R is the resistance of the high-resistance rod, the resistance by 10 ~ 20kΩ / V, according to the length of 0.5 ~ 105kV / cm selected, the resistance per unit capacity of l ~ 2W; C is capacitance to ground, can megabytes European table is at ground potential, C insulation resistance should reach a maximum amount limit megger to ensure the accuracy of measurement. C is the capacitance of 0.01 ~ 0.05μF, it should be able to withstand more than 3000V DC voltage. 5. judgment

(1) components and each piece of suspension insulator resistance of each pin post insulators not less than 300MΩ.

(2) 500kV suspension insulator insulation resistance of not less than 500MΩ.

It is worth noting that, when measuring multi-element post insulators insulation resistance of each element should be glued around the copper wire in the hierarchy, and then received the megger, in order to avoid the insulation resistance value measured at different locations much difference, caused by false judgments.