Vacuum circuit breaker insulation structures are currently divided into two types: ordinary insulation (also known as insulated cylinder type) and solid-encapsulated insulation.
Solid-encapsulated vacuum circuit breakers involve encapsulating the vacuum chamber with epoxy resin, embedding the vacuum interrupter and related conductive parts within the epoxy resin solid insulation material.
① Advantages: Small size, high insulation strength, good reliability and stability. It shields against external environmental influences, possessing strong environmental adaptability and pollution resistance. It effectively protects the vacuum interrupter from impacts and collisions.
② Disadvantages: Poor heat dissipation and high production cost. Widely used in industrial and high-requirement applications.
Ordinary insulation vacuum circuit breakers fix the interrupter inside an epoxy resin shielding cylinder. There is a certain gap between the plastic shielding cylinder and the vacuum interrupter, meaning phase-to-phase insulation relies on both the shielding cylinder and air.
① Advantages: Good heat dissipation and low cost.
② Disadvantages: Larger size and weaker resistance to impacts and collisions in the vacuum interrupter. Furthermore, due to the space between the arc-extinguishing chamber and the epoxy resin shielding cylinder, dirt can accumulate over time, resulting in poor environmental adaptability. It is generally used in locations without high requirements.
How to distinguish between ordinary insulated and solid-insulated vacuum circuit breakers: Ordinary insulated poles are larger, while solid-insulated poles are smaller; ordinary poles are not integrally molded, while solid-insulated poles are integrally molded; ordinary poles have a cap at the top, while solid-insulated poles do not.