Detailed description of the classification of inspection methods before the installation of composite insulators

The performance advantages of composite insulators have been described in detail in the previous articles. As a new type of composite electrical power fittings, composite insulators have comparative advantages in mechanical properties and electrical properties, compared with ceramics. The advantages of insulators and tempered glass insulators, composite insulators are obvious. However, before the installation of the insulator, it is still necessary to carry out sampling inspection and various performance experiments in order to carry out the installation and construction. The specific testing procedures are as follows.

Visual inspection

The appearance of the composite insulator can directly reflect whether the insulator is defective. In the visual inspection, the shed of the composite insulator and the sheath and the adhesive are inspected. The aging condition of the observation period and the corrosion of the end are as follows. In the case, the insulator is a direct scrap product.

1 The shed is catalyzed by corrosion and ruptured.

2 Electrical or electrical traces appear on the shed and sheath, and all of its length is greater than one tenth of the creepage distance of the insulator or that the etched depth is greater than 30% of the material layer at the designed location.

3 Degumming sealant failure degumming occurs.

4 water repellency decreased.

Mechanical load test

The purpose of this experiment is self-evident. The mechanical properties of composite insulators are their main properties. First, the mechanical load of the insulator is 75% mechanical load. After about 60 seconds, the mechanical load is raised to the damage value and recorded. Normal After three years of use of the load insulator in time, the damage value of this experiment should also be more than 90% of the load involved.

Drop experiment

The drop test for insulators is mainly to test the mechanical strength of the insulator and the age of the components such as the shed. The insulator is at a 45-degree angle to the ground and falls at a position of about one meter. It is free to fall three times. After three trials, the jacket of the shed should remain intact. Otherwise, the fragmentation indicates the old fire of the composite insulator and the umbrella skirt. The set is brittle.

Water seepage test

The main purpose of the water penetration test for insulators is to check the tightness of the insulator. The insulator is soaked in water for twenty-four hours. After drying, the DC voltage of 40 kV is measured. The leakage current of the composite insulator before and after water immersion should not be increased. More than 5μA.

The above experiments are carried out only by extracting 4-5% of the insulator, but the appearance inspection needs to be performed for each insulator.