The LW8(A)-40.5 Outdoor AC SF6 Circuit Breaker is a three-phase AC 50 Hz outdoor high-voltage electrical device that uses SF6 gas as both the arc-extinguishing and insulating medium. It adopts a compressed air arc-extinguishing structure, providing strong breaking capacity. It is widely used in Power Systems with a rated voltage of 40.5 kV for switching rated currents and short-circuit currents in substations and power plants. It can also be used as a link circuit breaker and for switching capacitor banks. The internal current transformers are used for measurement and protection, making this breaker an ideal product for modernization and upgrades.
The circuit breaker features a compact, floor-mounted, outdoor tank-type structure equipped with a CT14 spring operating mechanism. The mechanism is integrated with the main body, ensuring simple installation, easy commissioning, and reliable operation, making it suitable for frequent operations. Its lifespan exceeds 3,000 operations.
It adopts a compressed air arc-extinguishing structure with strong breaking capability, capable of interrupting a 40 kA fault current up to 12 times, setting a domestic record. The sealing performance is highly reliable, using imported sealing gaskets. The dynamic seal features a “Y”-shaped sealing ring with a spring pressure compensation structure.
The secondary wiring board for the current transformer is supplied by a joint venture, ensuring an annual leakage rate of less than 0.5%. The internal current transformers use microcrystalline alloy materials with high magnetic permeability, achieving an accuracy class of 0.2 or 0.2s. Based on user requirements, up to 12 current transformers can be included. The circuit breaker is capable of no-reignition operation in no-load long lines up to 50 km.
No. Parameter Name Unit Parameter Value 1 Rated voltage kV 40.5 2 Rated current A 1600 / 2000 3 Rated insulation level kV 95 (Grounded) / 185 (Contact gap) 4 Rated short-circuit breaking current kA 25 / 31.5 5 Rated out-of-step breaking current kA 7.9 / 10 6 Different-phase ground fault breaking current kA 27.4 / 34.8 7 Rated breaking current of single capacitor bank A 400 8 Rated operating sequence – O—0.3s—CO—180s—CO* 9 SF6 gas rated pressure (20℃ gauge pressure) MPa 0.45 10 Opening time (rated voltage) ms 30 ≤ t ≤ 40 11 Closing time (rated voltage) ms 60 ≤ t ≤ 80 12 Rated short-circuit making current (peak) kA 63 / 80 13 Rated short circuit duration s 4 14 Rated short-time withstand current kA 25 / 31.5 15 Rated peak withstand current kA 63 / 80 16 Mechanical life test Times 10,000 17 Accumulated breaking times (31.5kA/40kA short-circuit) Times 20 18 Rated current cumulative breaking times Times 2000 19 SF6 gas annual leakage rate % ≤0.5 20 SF6 gas trace moisture content ppm (V/V) ≤150×10⁻⁶ 21 External insulation leakage specific distance mm/kV ≥25 / ≥31** 22 Circuit breaker weight kg 1000
The LW8(A)-40.5 Outdoor AC SF6 Circuit Breaker is a cutting-edge high-voltage switching device designed for power substations and outdoor switchgear applications. It offers reliable, durable, and efficient electrical protection, ensuring stable operation even under extreme environmental conditions.
Engineered for AC power networks, the LW8(A)-40.5 breaker utilizes SF6 gas insulation for exceptional arc-quenching performance, low maintenance, and long service life. This article covers product introduction, core advantages, performance testing, and after-sales support, making it an essential guide for engineers, procurement managers, and technical professionals.
The LW8(A)-40.5 breaker is designed for 40.5kV outdoor power distribution systems. It serves as a primary protective device, interrupting fault currents and safeguarding equipment, personnel, and infrastructure.
High Voltage Capacity: Rated for 40.5kV operation.
AC Circuit Handling: Designed for reliable alternating current interruption.
SF6 Gas Insulation: Ensures excellent arc-quenching ability and minimal maintenance.
Outdoor Durability: Withstands humidity, temperature variations, and dust exposure.
Long Service Life: Mechanically and electrically robust for thousands of switching operations.
| Parameter | Value |
|---|---|
| Product Model | LW8(A)-40.5 Outdoor AC SF6 Circuit Breaker |
| Rated Voltage | 40.5 kV |
| Rated Current | 1250A / 2000A / 2500A |
| Rated Short-Circuit Current | Up to 31.5 kA |
| Insulation Medium | SF6 Gas |
| Arc Quenching | SF6 Gas Chamber |
| Mechanical Endurance | ≥ 10,000 operations |
| Operating Temperature | -40°C to +50°C |
| Applications | Outdoor substations, industrial grids, AC networks |
The LW8(A)-40.5 Outdoor AC SF6 Circuit Breaker offers several key advantages for high-voltage applications:
Stable performance under load and fault conditions.
Ensures uninterrupted service in critical infrastructure.
Resistant to corrosion, dust, and temperature extremes.
SF6 insulation maintains integrity over years of operation.
SF6 gas effectively extinguishes arcs during current interruption.
Reduces wear on contact surfaces and mechanical components.
Minimal inspection intervals compared to air-insulated or oil-based breakers.
Simplifies lifecycle management and reduces operational costs.
Suitable for urban substations, industrial facilities, renewable energy sites, and power grids.
The LW8(A)-40.5 breaker undergoes rigorous performance testing to ensure safety and reliability.
Dielectric Tests: Validates insulation under high voltage.
Short-Circuit Tests: Ensures interruption capability at rated fault currents.
Current Carrying Tests: Confirms continuous operation at rated current.
Endurance Testing: Simulates 10,000+ switching cycles to verify mechanical stability.
Temperature Testing: Confirms operation in extreme cold and heat.
Environmental Resistance: Exposure to humidity, dust, and UV radiation for outdoor reliability.
All units are factory-tested and certified according to IEC 62271 and GB/T standards.
Performance reports are provided for each breaker to assure compliance with specifications.
Verify the site grounding and foundation are compliant with electrical standards.
Transport the breaker using shock-proof packaging.
Mount the unit on a secure base, aligned with substation busbars.
Connect AC lines and check all terminal bolts for proper torque.
Test SF6 gas pressure and seal integrity before energizing.
Operate breaker within rated voltage and current limits.
Avoid frequent switching under load, which accelerates contact wear.
Monitor temperature and SF6 gas pressure regularly.
Engage the breaker only when protective systems are active and ready.
Proper maintenance and professional support maximize the lifespan of the LW8(A)-40.5 breaker.
Monthly: Visual inspection of housing, terminals, and gas chamber.
Quarterly: SF6 pressure check and electrical resistance measurement.
Annually: Lubrication of moving parts, inspection of contacts, and mechanical calibration.
Technical Support: 24/7 consultation for installation and troubleshooting.
Spare Parts Supply: Immediate access to certified replacement components.
Training: On-site or online training for maintenance and operational teams.
Warranty Services: Standard warranty covering manufacturing defects and SF6 gas integrity.
“Since integrating LW8(A)-40.5 breakers, our outdoor substations operate flawlessly even in harsh weather. The reliability and low maintenance requirements have reduced downtime significantly.”
“The breaker’s durable construction and efficient arc-quenching allow us to manage heavy loads continuously. Maintenance intervals are longer, saving both labor and operational costs.”
“Our solar substation relies on LW8(A)-40.5 breakers for stable, safe AC switching. Even during fluctuating generation conditions, the units operate consistently without failure.”
For safe transport, the LW8(A)-40.5 breaker is packaged to protect against environmental and mechanical damage:
| Packaging Component | Description |
|---|---|
| Outer Crate | High-strength, moisture-proof wooden crate |
| Internal Cushioning | Shock-absorbing foam and vibration-resistant padding |
| SF6 Gas Safety | Chamber sealed and factory-tested |
| Labeling | Product name, model, voltage, and handling instructions |
| Export Compliance | ISPM 15 and international shipping standards |
Air Freight: For urgent delivery, lightweight secure packaging.
Sea Freight: Heavy-duty crating for large orders.
Land Transport: Stabilized with anti-vibration fasteners.
Reliable Operation: Handles 40.5kV AC systems with minimal failure risk.
Durable Design: Resists outdoor environmental stress.
Low Maintenance: SF6 insulation reduces routine service requirements.
Global Compliance: IEC and GB/T certified.
Excellent Support: Comprehensive after-sales service ensures peace of mind.
The LW8(A)-40.5 Outdoor AC SF6 Circuit Breaker High Voltage Reliable Durable Electrical Protection for Power Substations is a premium solution for outdoor high-voltage networks. Its robust SF6 insulation, durable design, and proven reliability make it ideal for industrial, utility, and renewable energy applications.
With rigorous performance testing, professional after-sales support, and proven customer satisfaction, the LW8(A)-40.5 breaker ensures safe, stable, and long-term electrical protection in critical infrastructure.
Phone: +8613736779975
E-mail: sales@vcbbreaker.com
Address: 66 Punan Road, Yueqing Economic Development Zone, Zhejiang, China
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