Supporting conductors: In overhead transmission lines, post insulators bear the weight of the conductors.

Preventing current back to ground: Ensuring that live conductors do not experience current back to the ground, protecting system safety.

Isolation: In substations and electrical equipment, used to support and isolate conductive parts, preventing electrical faults.

Material: Typically made of ceramic, glass, or composite materials, sometimes combined with metal accessories (such as steel feet and iron caps).

Non-Penetrating Performance: Most post insulators employ a "non-penetrating" design, meaning the external flashover distance and the insulation capacity of the internal through-path are almost equal. In the event of a fault, only external flashover will occur, without leading to breakdown of the internal dielectric.

Advantages of Composite Materials: Composite post insulators offer advantages such as light weight, strong shock resistance, and excellent resistance to pollution flashover.

• Essential in 110kV–500kV high-voltage substations, supporting busbars and conductors in indoor/outdoor distribution equipment.
• Used in high-voltage switchgear, isolating switches, and circuit breakers to provide insulation and mechanical support for live parts.
• Applied in power transmission lines of industrial plants (steel, chemical), power stations, and renewable energy facilities (wind, solar farms).
• Ideal for urban power grids and coastal areas, where resistance to humidity, salt spray, and industrial pollution is critical.
• Integrated into specialized high-voltage systems for railways, metros, and mining, ensuring safe power distribution in harsh operational conditions.