The insulator tester under UHV power can help many power workers conduct various power tests more conveniently.

In daily work, electricians often need to perform zero value testing on insulators to test the string voltage distribution value of insulators. Therefore, they need to use an insulator zero value tester. The equipment has certain test results during the testing process. This article will briefly introduce the standards for insulator zero value testers.

1、 Measure voltage distribution (or spark gap):

1. If the voltage value of the tested insulator is less than 50% of the standard value (see Table 1 and Table 2 for voltage distribution standard values), it is judged as insulator degradation;

2. The voltage value measured by the insulator distribution voltage tester is greater than 50% of the predetermined standard value of the insulator, and significantly lower than the qualified voltage value judged as the insulator on both adjacent sides;

3. Not discharging at the specified spark gap distance and discharge voltage is a degraded insulator.

2、 Measure insulation resistance (zero value):

1. Voltage level 500 kV: If the insulation resistance of the insulator is less than 500 m Ω, it is judged as insulator degradation;

2. 500kV voltage level: If the insulation resistance of the insulator is less than 300M Ω, it is judged as a degraded insulator

3、 Power frequency withstand voltage test

Insulators with mechanical damage loads ranging from 60kN to 530kn can withstand a dry frequency withstand voltage of 60kV for 1 minute. Insulators with large coil diameter and anti pollution type can withstand the dry frequency flashover voltage corresponding to ordinary insulators. Degraded insulators are not allowed to be used.

4、 Check

The defect area of the glaze does not meet the requirements of GB772, and the porcelain parts have cracks, damages, steel feet, loose cement, etc., which are judged as deteriorated insulators.

5、 Mechanical strength test

When assessing organic damage, reducing the rated load by 85% is considered as a degradation of the mechanical strength of the insulator

The standard for using insulator zero value tester has certain guiding significance for the testing and use of equipment. Electricians need to compare test results according to the above testing standards when using equipment.