72.5 – 145kv GCB (Gas Circuit Breaker)
The 145 kV GCB (Gas Circuit Breaker) is specifically designed for high-voltage power system applications up to the 245 kV class. Utilizing the superior arc-extinguishing and insulating properties of sulfur hexafluoride (SF₆) gas, it integrates precision mechanical engineering with advanced intelligent control technology. The breaker serves not only as a critical device for circuit closing, continuous current carrying, and fault interruption, but also as a vital safety barrier that isolates grid faults and ensures the reliable and continuous operation of the power system.
Features of Compactness GCB
- Excellent Arc-Extinguishing and Insulation Performance
- High-purity SF₆ gas is used as the arc-extinguishing medium, and the arc-extinguishing chamber is optimized through advanced hydrodynamic design. Compared with traditional equipment, the recovery speed of the arc-gap medium is increased by more than 30%, enabling faster and more reliable interruption of rated short-circuit breaking currents as well as various abnormal currents, thereby effectively avoiding the risk of arc re-ignition.
- At the same time, the high dielectric strength of SF₆ gas ensures stable and reliable insulation performance under the rated voltage of 145 kV and during transient overvoltage conditions. The partial discharge level is ≤5 pC, significantly reducing the risk of insulation degradation and breakdown.
- Compact Structure and Strong Environmental Adaptability
- A modular and compact design is adopted, with the overall volume reduced by approximately 15% compared with products of the same voltage class, significantly saving substation floor space and installation area while accommodating various indoor and outdoor installation configurations. The enclosure is manufactured from high-strength, weather-resistant aluminum alloy and treated with advanced anti-corrosion and anti-ultraviolet processes.
- Combined with a protection rating of IP54 (outdoor type) or IP67 (special protection type), the equipment can withstand harsh environmental conditions such as sand, heavy rain, salt spray, and condensation. The wide-temperature design supports reliable operation in extreme ambient temperatures ranging from −55 °C to +55 °C and meets the requirements of special operating conditions, including high altitude (≤4,000 m) and high humidity (relative humidity ≤95%).
- High Reliability and Long-Life Design
- Core components, including the arc-extinguishing chamber and operating mechanism, are sourced from a proven and mature localized supply chain. Key manufacturing processes are subject to multiple quality control measures, such as ultrasonic flaw detection and airtightness testing.
- The mechanical service life of the spring-operated mechanism is ≥10,000 operations, while the hydraulic operating mechanism achieves ≥20,000 operations, both far exceeding industry-average performance. The SF₆ gas leakage rate is ≤0.1% per year, demonstrating excellent sealing integrity. In addition, the equipment offers a maintenance-free service period of up to 10 years, significantly reducing operation and maintenance costs as well as unplanned outage risks.
- Flexible Adaptability and Convenient Installation
- The rated current (3,150 A / 4,000 A / 5,000 A) and short-circuit breaking current (40 kA / 50 kA / 63 kA) can be customized to meet specific application requirements, accommodating the load demands of substations and transmission lines with different capacities.
- The equipment requires no complex commissioning during installation. The operating mechanism and arc-extinguishing chamber are fully pre-assembled at the factory. On site, only mechanical fixing, electrical wiring, and SF₆ gas filling are required, improving installation efficiency by approximately 40%.
- Short On-Site Installation Cycle
- Thanks to the extensive use of large, factory pre-assembled and fully tested units—typically comprising the entire bay—the on-site installation time is significantly reduced.
Environmental and Installation Conditions
| No. | Item | Unit | Indoor | Outdoor |
| 1 | Installation | — | Indoor | Outdoor |
| 2 | Ambient Air Temperature | °C | −25 ~ +40 | −40 ~ +50 |
| 3 | Solar Radiation | W/m² | Not applicable | ≤ 1000 |
| 4 | Altitude | m | 1000 / 2000 / 3000 / 4000 | 1000 / 2000 / 3000 / 4000 |
| 5 | Pollution Class | — | Not applicable | Class II / III / IV |
| 6 | Ice Coating Thickness | mm | Not applicable | ≤ 20 |
| 7 | Wind Speed | m/s | Not applicable | ≥ 34 |
| 8 | Humidity (Daily Average) | % | ≤ 95 | ≤ 100 |
| 9 | Applicable Standards | — | IEC 62271-203 IEEE 37.04-2018 | IEC 62271-203 IEEE 37.04-2018 |
170 – 245kv GCB (Gas Circuit Breaker)
The 170–245 kV GCB (Gas Circuit Breaker) is specifically designed for high-voltage applications within the 170–245 kV range. Leveraging the superior arc-extinguishing and insulating properties of sulfur hexafluoride (SF₆) gas, it combines precise mechanical engineering with advanced intelligent control technology. The breaker serves not only as a critical device for circuit closing, current carrying, and fault interruption, but also as a vital safety barrier that isolates grid faults and ensures the reliable, continuous operation of the power system.
Features of Compactness GCB
- Excellent Arc-Extinguishing and Insulation Performance
- High-purity SF₆ gas is used as the arc-extinguishing medium, and the arc-extinguishing chamber is optimized through advanced hydrodynamic design. Compared with traditional equipment, the recovery speed of the arc-gap medium is increased by more than 30%, enabling rapid interruption of rated short-circuit breaking currents as well as various abnormal currents, including no-load line current and transformer magnetizing current. The arc-extinguishing time is ≤20 ms, effectively preventing arc re-ignition.
- At the same time, the high dielectric strength of SF₆ gas ensures stable and reliable insulation performance under rated voltage and during transient overvoltage conditions. The partial discharge level is ≤5 pC, significantly reducing the risk of insulation degradation and breakdown.
- Compact Structure and Strong Environmental Adaptability
- A modular and compact design is adopted, reducing the overall volume by approximately 15% compared with products of the same voltage class. This saves floor and installation space in substations and allows flexible indoor or outdoor installation configurations. The enclosure is constructed from high-strength, weather-resistant aluminum alloy and treated with anti-corrosion and anti-ultraviolet coatings.
- With protection ratings of IP54 (outdoor type) and IP67 (special protection type), the equipment can withstand harsh environmental conditions such as sand, heavy rain, salt spray, and condensation. The wide-temperature design supports reliable operation in extreme ambient temperatures from −55 °C to +55 °C, meeting the requirements of special conditions such as high altitude (≤4,000 m) and high humidity (relative humidity ≤95%).
- High Reliability and Long-Life Design
- Core components, including the arc-extinguishing chamber and operating mechanism, are sourced from a well-established localized supply chain. Key manufacturing processes are subject to multiple quality control measures, such as ultrasonic flaw detection and airtightness testing.
- The mechanical service life of the spring-operated mechanism is ≥10,000 operations, while the hydraulic mechanism achieves ≥20,000 operations, both far exceeding industry-average standards. The SF₆ gas leakage rate is ≤0.1% per year, demonstrating excellent sealing performance. Additionally, the equipment offers a maintenance-free service period of up to 10 years, significantly reducing operation and maintenance costs as well as unplanned outage risks.
- Flexible Adaptability and Convenient Installation
- The rated current (3,150 A / 4,000 A / 5,000 A) and short-circuit breaking current (40 kA / 50 kA / 63 kA) can be customized to meet specific application requirements, accommodating the load demands of substations and transmission lines of various capacities. No complex commissioning is required during installation. The operating mechanism and arc-extinguishing chamber are fully pre-assembled at the factory. On site, only mechanical fixing, electrical wiring, and SF₆ gas replenishment are needed, significantly improving installation efficiency.
- Short On-Site Installation Cycle
- Thanks to the extensive use of large, factory pre-assembled and fully tested units—often comprising the entire bay—on-site installation time is significantly reduced.