SF6 Tank Circuit Breaker VB-110

The SF6 gas-insulated tank circuit breaker VB-110, designed with a spring-operated mechanism and integrated current transformers, is intended for use in both indoor and outdoor distribution systems operating at 50 Hz with a nominal voltage of 110 kV. Suitable for moderate to cold climates, the VB-110 breaker features an arc-quenching unit and current transformers integrated into the inputs, offering advantages in transport compactness, high factory readiness, and reduced installation and commissioning costs.

The breaker’s tank is enclosed within a thermally insulated composite housing, eliminating the need for additional insulation materials, thus ensuring reliable operation in cold environments. Each breaker is equipped with a unified control and monitoring cabinet for all three poles (phases), along with a digital management and monitoring system that complies with IEC 61850 standards.

Structurally, the VB series circuit breaker consists of a support frame, to which the poles, spring mechanism, and control cabinet are mounted. The frame is fabricated from high-strength steel grade 09G2S with a hot-dip galvanized coating of specified thickness, featuring dedicated enclosures for the breaker’s trip spring and operating mechanism rods. Additionally, the frame is equipped with specialized lifting points to facilitate easy installation and handling during loading and unloading.

Each breaker pole is housed within an elliptical tank made from high-strength AMg6 aluminum alloy, designed with specific features for mounting cone-shaped bushings. One bushing contains the built-in current transformer block, while the opposite side houses the arc-quenching chamber. For climate applications requiring XL classification (operational temperature as low as -60°C), an additional heating system and thermal protection are uniformly installed around the tank. These heating elements are housed within durable composite protective covers.

The breaker is also equipped with a density monitor with temperature compensation on the casing to ensure consistent SF6 gas density. Alarm settings for density variations are integrated within the control cabinet, providing real-time status monitoring.