Vacuum circuit breaker PVB-12

Vacuum circuit breakers for indoor installation PVB (hereinafter referred to as "breakers") are designed for switching three-phase alternating current networks with a frequency of 50 Hz with a rated voltage up to 12 kV in normal and emergency modes. The breakers provide automatic re-closing capability and have high reliability and a long service life.

The breakers can be supplied in stationary and withdrawable versions. The breaker's drive is spring-operated, with the possibility of spring tensioning manually or by using an electric motor. Breakers can be supplied together with an adaptation kit (retrofit) for replacing obsolete oil and gas circuit breakers.

FEATURES OF THE TECHNICAL SOLUTION

The multilayer construction of the main pole housing, made of silicone and epoxy compound, provides high dielectric characteristics and strength. The first layer of silicone compound is applied directly to the vacuum arc chamber to provide high insulation strength of the vacuum arc chamber surface and compensate for the difference in coefficients of thermal expansion of the housing and the ceramic insulator. The second layer of epoxy compound provides not only dielectric strength but also high mechanical strength.
The breaker's construction consists of a frame, which is the basis of the breaker and is mounted in a compartment (stationary version) or on a withdrawable element (withdrawable version), and three poles with vacuum arc quenching chambers installed on the breaker's frame. Control and drive status indication devices are located on the breaker's panel.
Each vacuum arc quenching chamber is located in a vertical split housing, which has a tube shape, ensuring ease of maintenance and reliable natural cooling of the chamber.
The independent action drive of the breaker is a spring-motor mechanism with manual or electric energy accumulation function. It is located in the breaker's frame. The drive is an integral part of the breaker and, when performing operations, the construction itself prevents the occurrence of out-of-phase network conditions.
The frame itself is divided into three mounting sections by two metal plates. Thus, the breaker represents a single unit with a drive and arc quenching chambers. This design, which combines the operational potential of the spring-motor drive and the capabilities of the arc quenching chambers in the on-off mode, has allowed eliminating unnecessary intermediate connections and increasing the reliability of the breaker.
The metal parts of the drive, housing, metal connecting elements of the breaker, drive mechanism, and drive have effective protection and resistance to adverse environmental influences.