Factory supplied P-70 Disconnect Switch Post Insulator - P-70 Porcelain Post Insulator – Johnson

Product Definition

Post insulator is a special insulation control which can play an important role in overhead transmission line. In the early years, pillar insulators were mostly used for telephone poles, which were gradually developed to hang a lot of suspension-like insulators at the end of the high-voltage wire connection tower to increase the creepage distance. They are usually made of silica gel or ceramic, and are called insulators.
Insulator in overhead transmission lines with two basic role, namely support wire and prevent the current back, these two functions must be guaranteed, insulator should not produce change due to environmental and electrical load conditions lead to breakdown and flashover failure, or insulator will be lost, will damage the whole line of use and operating life.

Performance

1. Post insulators are in accordance with the provisions of GB8287.1 “Technical Conditions for High Voltage Post Porcelain Insulators” and GB12744 “Pollution Resistant Outdoor Bar Post Porcelain Insulators”. It also complies with the requirements of the international standard IEC168, Tests on Ceramic or glass Post Insulators for internal and outdoor use in systems with nominal Voltages above 1000 V, and IEC publication 815, Guidelines for the selection of Insulators under pollution conditions.

2, insulator mechanical strength is high, small dispersion, safe and reliable operation.

3, insulator low temperature mechanical performance is good.
In order to test the cryogenic mechanical properties of the product, the zSW1-110/4 insulator was tested in the cryogenic laboratory of the Institute of Water Resources, Songliao Water Conservancy Commission, to simulate the change of outdoor temperature in winter. After several temperature cycles, the test crystals were tested for bending failure at low temperature. The test results show that the bending failure strength of insulators at -40℃ has no significant change compared with that at room temperature.

4. Low radio interference.
An insulator with rated voltage of 550kV can produce radio interference not greater than 500μV at 1.1 times the maximum operating phase voltage, no visible corona on a clear night, and visible corona voltage up to 450kV.