LW30-220 Outdoor High-Voltage Sulfur Hexafluoride (SF6) Circuit Breaker
The LW30-220 Outdoor High-Voltage SF6 Circuit Breaker is a reliable 220kV–252kV transmission-class switching device designed for high-voltage power transmission and substation applications. Utilizing SF6 gas as the insulation and arc-extinguishing medium, it provides excellent breaking performance, strong insulation capability, and stable long-term operation. With advanced self-energy arc-extinguishing technology, high fault current interruption capability, and a robust outdoor structure, the LW30-220 is widely used for transmission line protection, transformer feeder protection, grid interconnection, and large-scale substation applications.
Get a QuoteOverview
The LW30-220 Outdoor High Voltage SF6 Circuit Breaker is a three-phase AC 50Hz sulfur hexafluoride (SF6) circuit breaker developed for 220kV–252kV high-voltage power transmission and transformation systems. Using SF6 gas as both the insulation and arc-extinguishing medium, it provides reliable switching, control, and fault protection for critical power network applications.
The breaker is mainly applied in 220kV transmission line protection, main transformer incoming feeder protection, and grid interconnection switching for large-scale substations. With high breaking capability, excellent insulation performance, and long-term operational reliability, the LW30-220 is designed to meet the demanding requirements of modern high-voltage transmission networks.
Featuring advanced SF6 interruption technology and a robust outdoor structure, the LW30-220 SF6 Circuit Breaker provides a dependable solution for ensuring safe, stable, and efficient operation of regional power grids.
Features
Efficient Arc Extinguishing and Reliable Breaking Performance
The LW30-220 SF6 Circuit Breaker adopts an advanced self-energy arc-extinguishing technology with auxiliary pressure-blast assistance. During the opening operation, the thermal energy generated by the arc heats the SF6 gas inside the interrupter chamber, creating a high-pressure gas flow. Combined with the mechanical auxiliary pressure-blast effect, the airflow is accurately directed through the nozzle to achieve rapid and reliable arc extinction.
The optimized interrupter design provides a short arcing time of ≤2 cycles and eliminates current chopping, effectively reducing the risk of switching overvoltage and protecting connected power equipment.
For 220kV high-voltage transmission systems with high short-circuit current requirements, the arc chamber airflow structure is specially optimized, enabling a rated short-circuit breaking current of up to 50kA. The breaker can continuously interrupt rated short-circuit current 12 times without maintenance, meeting the requirements of modern power grids with frequent fault clearing demands.
Excellent Electrical Endurance and Mechanical Reliability
High Electrical Performance
The LW30-220 provides strong insulation capability and fault current withstand performance for demanding high-voltage applications.
Key electrical characteristics include:
- Rated lightning impulse withstand voltage to ground: 550kV
- Rated 1-minute power frequency withstand voltage to ground: 252kV
- Rated short-circuit making current (peak): 125kA
- Rated short-time withstand current (4s): 50kA
These capabilities enable the breaker to withstand severe electrodynamic stress during short-circuit faults and ensure reliable protection for high-voltage transmission equipment.
Long Mechanical Service Life
The breaker is equipped with the proven CT30 spring operating mechanism, combined with high-precision transmission components and optimized buffering structures to ensure stable mechanical operation.
The mechanical endurance exceeds 10,000 operations, significantly reducing equipment replacement frequency and lowering lifecycle maintenance costs.
Low Energy Consumption and Reduced Operating Noise
The self-energy arc-extinguishing design greatly improves operating efficiency. Compared with conventional pressure-blast circuit breakers, operating energy consumption is reduced by more than 40%.
The operating mechanism produces noise levels of ≤75dB, helping meet environmental noise requirements for outdoor high-voltage equipment installations.
Excellent Environmental Adaptability
The LW30-220 Outdoor SF6 Circuit Breaker is designed for reliable operation under various harsh outdoor conditions.
Environmental performance includes:
- Standard operating temperature range:-30℃ to +40℃
- Customized low-temperature versions available for -40℃ environments
- Wind resistance up to ≤35m/s
- Ice coating resistance up to ≤15mm
The porcelain insulators feature an anti-pollution flashover coating with a creepage distance of ≥31mm/kV, meeting GB/T 5582 Pollution Level IV requirements. This allows reliable long-term operation in industrial environments and coastal areas with high salt fog exposure.
The standard version supports installation at altitudes below 2000m. For high-altitude applications, customized models can operate at elevations up to 4000m through optimized insulation design and SF6 gas pressure compensation technology.
Technical Data
| Item | Unit | Parameter | |
| Rated Voltage | kV | 220 | |
| Rated Current | A | 2500 / 3150 / 4000 | |
| Rated Frequence | Hz | 50 | |
| Rated Short-Circuit Breaking Current | kA | 40 / 50 | |
| Rated Short-Circuit Making Current (Peak) | 100 / 125 | ||
| Rated Short-Time Withstand Current (4s) | 40 / 50 | ||
| Rated Peak Withstand Current | 100 / 125 | ||
| Rated Insulation Level | Lightning impulse (to ground) | kV | 550 |
| Lightning impulse (fracture) | 630 | ||
| Power frequency withstand voltage (to ground) | 252 | ||
| Power frequency withstand voltage (fracture) | 290 | ||
| SF6 Gas Parameters | Rated pressure (gauge pressure at 20℃) | Mpa | 0.5 |
| Gas replenishment pressure | 0.47 | ||
| PaLockout pressure | 0.45 | ||
| Annual gas leakage rate | % | ≤0.3 | |
| Moisture content | ppm(v/v) | ≤150 | |
| Operating Performance | Opening time | ms | ≤60 |
| Closing time | ≤100 | ||
| Close-open time | ≥120 | ||
| Rated operating sequence | / | Open—0.3s Close-Open—180s Close-Open | |
| Mechanical Life | Times | ≥10,000 | |
| Equipment Weight | kg | Approximately 3500kg (without CT) / 4000kg (with CT) | |
| SF6 Gas Filling Capacity | kg | Approximately 25kg | |
Structural Design and Maintenance Advantages
Stable and Reliable Structural Configuration
The LW30-220 Outdoor SF6 Circuit Breaker adopts a three-phase separated porcelain post-type structure. The three poles are mounted on a common base frame manufactured from high-strength welded steel sections, providing excellent mechanical strength, vibration resistance, and seismic performance up to 8 degrees.
Each phase is equipped with an independent interrupter chamber and porcelain post insulator. The interrupter chamber integrates the fixed contact, moving contact, nozzle, and adsorption components into a sealed structure, effectively reducing SF6 leakage risks and improving long-term operational reliability.
The three phases are connected through steel pipes to achieve SF6 gas communication, ensuring balanced gas pressure between phases and maintaining consistent arc-extinguishing and insulation performance.
Intelligent and Convenient Maintenance Design
Advanced SF6 Gas Monitoring System
The LW30-220 is equipped with an intelligent electronic SF6 density relay that continuously monitors gas pressure and temperature in real time. Through the 485 communication interface, operating data can be transmitted to the monitoring system for remote supervision.
When abnormal gas conditions occur, the system automatically provides audible and visual alarms and can activate operation locking functions to improve equipment safety. A local pointer-type density gauge is also provided for convenient on-site inspection and maintenance.
Integrated Component Design
The breaker supports built-in current transformer (CT) configurations with accuracy classes up to 0.2S, meeting the measurement and protection requirements of high-voltage transmission networks.
The integrated CT design reduces external components and potential failure points. The operating mechanism cabinet adopts an IP54 protection rating and is equipped with built-in heating and dehumidification systems, preventing condensation-related issues and ensuring reliable operation in low-temperature environments.
Modular Maintenance Structure
The interrupter chamber and operating mechanism feature a modular design, allowing independent removal and maintenance to reduce equipment downtime.
Dedicated maintenance access points are provided for key components, enabling technicians to inspect contact wear, sealing performance, and component aging efficiently, improving maintenance convenience and reducing service time.
Application Scenarios
220kV Regional Transmission Networks
The LW30-220 SF6 Circuit Breaker serves as a key protection device for 220kV backbone transmission lines, supporting grid load management and fault clearing to ensure reliable power transfer between regional networks.
Large-Scale Hub Substations
The breaker is suitable for high-voltage side protection applications in 220kV substations, including transformer incoming feeders, outgoing lines, and bus sectionalizing systems. It provides reliable performance under high-voltage and high-current operating conditions.
Renewable Energy Grid Connection Projects
The LW30-220 is suitable for 220kV booster substations of large-scale wind power and photovoltaic energy bases. It provides reliable interruption of fluctuating currents and fault currents, supporting stable integration of renewable energy into the main power grid.
Industrial High-Voltage Power Distribution
The breaker meets the requirements of 220kV industrial power systems in sectors such as metallurgy and chemical industries. Its high reliability and strong fault-handling capability help ensure continuous and stable power supply for large industrial facilities.
Compliance with International Standards
The LW30-220 Outdoor High Voltage SF6 Circuit Breaker complies with major national and international standards, including:
- GB1984 AC High-Voltage Circuit Breakers
- GB/T 11022 Common Technical Requirements for High-Voltage Switchgear and Controlgear Standards
- IEC 62271-100 High-Voltage AC Circuit Breakers
The product has successfully passed type testing conducted by the National High-Voltage Electrical Equipment Quality Supervision and Inspection Center, with electrical and mechanical performance meeting advanced industry requirements.
Designed for global 220kV high-voltage transmission networks, the LW30-220 provides reliable compatibility, safe operation, and long-term service performance for modern power systems.
