SF6 Circuit Breakers
SF6 High Voltage Circuit Breakers (40.5kV - 252kV)
Reliable, IEC-certified solutions for global power transmission and distribution projects.
- ISO 9001 Certified
- KEMA Type Tested
- 10+ Years Experience
SF6 Circuit Breakers Manufacturer
Choosing a Reliable Manufacturer
electing the right SF6 circuit breaker manufacturer is crucial for ensuring the reliability and performance of your electrical system. Consider these key factors:
Technical Expertise
Evaluate the manufacturer's engineering capabilities and technical knowledge.
Manufacturing Quality
Look for modern production facilities with stringent quality control processes.
Certifications
Verify international and national certifications for products and manufacturing processes.
Track Record
Research the company's project history and customer references.
Why Choose Zhejiang Diji Power
Since our establishment in 2013, Zhejiang Diji Power Co., Ltd. has specialized in designing and manufacturing high-quality SF6 circuit breakers for global markets.
- Advanced manufacturing facility in Liushi Town, Yueqing – China’s Electrical Capital
- Comprehensive quality management system with rigorous testing protocols
- Experienced engineering team with deep industry knowledge
- Full range of SF6 circuit breakers from 7.2kV to 35kV
- Custom solutions to meet specific project requirements
- Global service network providing responsive technical support
SF6 Circuit Breaker Diagram
The SF6 circuit breaker structure diagram reveals several key components that work together to ensure reliable operation:
- Arc interruption chamber housing the fixed and moving contacts
- SF6 gas system for insulation and arc quenching
- Operating mechanism (spring, hydraulic, or pneumatic)
- Insulating support structures
- Bushings for electrical connections
- Control circuits and auxiliary contacts
- Gas density monitoring system
This integrated design ensures optimal performance while maintaining the highest safety standards for electrical distribution systems.
Characteristics of SF6 Gas
SF6 gas is the heart of these circuit breakers, offering unique properties that make it ideal for electrical applications:
- Superior insulation strength (2-3 times higher than air)
- Excellent arc-quenching capability due to high electronegativity
- Chemical stability and inertness under normal conditions
- Non-toxic in pure state (though decomposition products require handling care)
- High thermal conductivity for efficient heat dissipation
- Non-flammable and self-restoring insulation properties
- Outstanding dielectric recovery properties after arc extinction
These characteristics make SF6 the preferred medium for high voltage circuit breakers despite environmental considerations.
SF6 CIRCUITS BREAKERS 40.5KV- 252KV
LW36-72.5kV 126kV 3150-40 High Voltage AC SF6 Tank Circuit Breaker
LW36-72.5T high-voltage Ac SF6 tank circuit breakers and current transformer circuit breaker willbe together, and interruptersmounted horizontally in the grounded aluminum alloy housing, equipped with a CT26 spring operating mechanism, which The partsused are few,the lavoutis simole and compact the whole is solid and durable, the switch is oil-iree, the mechanical characlerislicsare excellent and the relability is high.
All the important parts adopt the CNC machining and machining center equipment processingThe bearings adopt imported international brand bearings , lNA, SKF and other brands), mechanical life up to 10,000 times. it can beused for control and protection of 72.5 (126) kV power transmission and distribution system.lt can also be used in contact open circuitand opening and closing capacitor banks.
- High throughflow capability(3150A); short circuit breaking current when 40℃:31.5kA.
- Long life electrical life: 31.5kAx24times(25kAx31times); mechanical life: 10000times with simple adjustment.
- High reliability it shares the arc extinguish chamber with LW36-126 type, and the inner insulation allowance is great, spring mechanismso the structure is simple and also can be operated frequently.
- Breaking performance is reliable.
- Sealabitity is reliable, The annual leakage rate of SF6<0.5%.
- Suitable for foul environment(suitable for the area that filth level is iV and the temperature is betweth-40′ to 40’℃).
LW43-252/4000A Sf6 Outdoor High Voltage Circuit Breaker
The LW-25214000-50 self-extinction AC circuit breaker, which is an outdoor type, finds its universal range of applications for electrical systems with an elevation not greater than 2000 m, ambient temperature not lower than -30°C, dirtiness grade not higher than IV, alternating current 50 Hz, and a maximum voltage of 126 kV. It is used for cutting the rated current, malfunction current or switching circuitry to control and protect the electrical system, and it can also be used for connecting circuit breakers.
SF6 gas is employed as the arc-extinguishing medium and dielectric material. Self-extinction technology and a new-type spring-operating mechanism are introduced in this SF6 circuit breaker. Thus, the circuit breaker possesses good qualities, including long electrical life, low operation power, low noise, high reliability, simple structure, small size, and long overhaul periods. It can fully replace imported units of the same type.
LW36-126 72KV 126KV 145KV 220kv Sf6 Circuit Breaker
The LW36-145/3150-40 sel-extinction Ac circult breaker which is outdoor type finds its universalrange of applcations forthe electrical system withelevaion not areater than 3000m,.ambienttemperature not lower than-40’c,dirtiness grade not higher than iy,altemaing curent 50Hz and the maximumvoltage 145ky,itis used forcuting the rated current, mallunction curent or switching the circuty, to control and protectthe electricalsystem.anditcanalso be used for connecting with the circuit breaker.
The gas of the SF6 is employed as the arc-extinguishing medium and the dielectric material.The sel-extinction technology and the new-type springoperating mechanism are inroduced in the SF6 circuit breaker, Thus the circuit breaker has good qualities with long electricallile,lowoperalion powerlower noise, high reliability, simple structure, small and long overhaul periods.t can fuly replace the import same type one.
LW8-40.5 Series 33KV 36KV Live tank Sulfur Hexafluoride Circuit Breaker
The LW8-40.5 breaker has the structure which is outdoor porcelain posttype. it can be matched with cT35 spring mechanism and has T shapeThe circuit breaker is small and ight and has good qualities with low operation power,lowernoise, high reliability, simple structure. lt is alsoconvenient for the operator to instaland debug the breaker.The mechanicallife is not less than 10000 times and the breaker can be operated frequently.
The breaker uses pneumaic arc-extinguishing chamber, so the breaking perormance is excellent and the electricallile can reach up to 20 imesThe sealabililty is reliable. Staic seal uses O shape grommet struclure, while dynamic sealuses structure ofV shape grommet with spring pressureThe secondary terminal block is produced by imported mould according to the pressure injection technics So it has high performance of ageingresistance and makes sure that the annual leakage rate ofSF6≤0.5%.The metal frame and the support of the circuit breaker are bended with a whole deep steel plate. ituses high strength standard accessories andthe mechanism is reliable.
The measure iron cove of the inner or outer curent transformer is made of materials with the performance of crvstalitelallovthioh conducionMagnetic. So the accuracy class can reach up to 0.2 or0.2s. Every phase of the product can match with 2-4 pieces of curent transformers
SF6 Circuit Breaker Specifications & Selection Guide
Understanding SF6 Circuit Breaker Rating
When selecting an SF6 circuit breaker, understanding the key rating parameters is essential for ensuring proper application and performance in your electrical system.
| Parameter | Description | Typical Range |
|---|---|---|
| Rated Voltage | Maximum operating voltage the breaker can handle | 40.5kV - 252kV |
| Rated Current | Maximum continuous current during normal operation | 630A - 4000A |
| Short-Circuit Breaking Capacity | Maximum fault current the breaker can safely interrupt | 16kA - 63kA |
| Insulation Level | Withstand voltage against lightning and switching impulses | Up to 170kV BIL |
| Operating Sequence | Standard cycle of operations | O-0.3s-CO-3min-CO |
SF6 Circuit Breaker Current Rating
The current rating of an SF6 circuit breaker determines its ability to carry and interrupt electrical current safely:
- Rated continuous current: 630A, 1250A, 2000A, 3150A, 4000A
- Short-time withstand current: Typically rated for 1-3 seconds
- Breaking capacity: 16kA, 25kA, 31.5kA, 40kA, 50kA, 63kA
- Making capacity: 2.5 times the rated breaking capacity
Proper current rating selection ensures the breaker can handle both normal load currents and fault conditions effectively.
SF6 Circuit Breaker Voltage Range
SF6 circuit breakers are manufactured for various voltage levels, making them suitable for different applications:
- Medium voltage: 7.2kV, 12kV, 24kV, 35kV (distribution systems)
- High voltage: 36kV, 72.5kV, 145kV, 245kV (transmission substations)
- Extra high voltage: 300kV, 420kV, 550kV, 800kV (major transmission systems)
SF6 circuit breakers are manufactured up to the voltage of 800kV for ultra-high voltage applications, demonstrating their versatility across the entire power system.
Discuss Your SF6 Breaker Needs
To ensure quick matching of the most suitable vacuum circuit breaker for you, please provide the voltage level, load current, and installation environment (such as indoor/outdoor) of the existing system, and we will immediately recommend an optimization solution for you!
SF6 Circuit Breaker Advantages and Disadvantages
Compact Design
SF6 breakers require significantly less space than air or oil circuit breakers of comparable ratings.
High Interrupting Capacity
Capable of breaking very high fault currents safely and efficiently.
Long Maintenance Intervals
Typically requires maintenance only after 10,000-15,000 operations or 10-15 years.
Low Operating Noise
Operates more quietly than other types of circuit breakers.
Non-Flammable
SF6 gas is non-flammable, eliminating fire hazards associated with oil circuit breakers.
Environmental Concerns
SF6 is a potent greenhouse gas, requiring careful handling and recovery to prevent leakage.
Low Temperature Limitations
SF6 can liquefy at very low temperatures, potentially affecting operation in extreme cold.
Initial Cost
Higher initial investment compared to some alternative technologies.
Moisture Sensitivity
Requires monitoring and control of moisture levels within the gas system.
Specialized Handling Equipment
Requires special tools and procedures for gas handling during maintenance.
VCB vs SF6 Breaker: Comprehensive Comparison
| Feature | SF6 Circuit Breakers | Vacuum Circuit Breakers (VCB) | |
|---|---|---|---|
| Voltage Range | Medium to ultra-high voltage applications (up to 800kV) | Primarily medium voltage applications (up to 38kV) | |
| Arc Quenching Medium | Sulfur Hexafluoride gas | Vacuum | |
| Environmental Impact | Higher (SF6 is a potent greenhouse gas) | Lower (no greenhouse gas emissions) | |
| Size | Larger at comparable ratings | More compact at comparable ratings | |
| Maintenance Requirements | Moderate (gas monitoring required) | Low (sealed for life) | |
| Mechanical Life | 10,000–15,000 operations | 30,000–100,000 operations | |
| Operational Temperature | Limited in extremely cold environments | Wider temperature range | |
| Typical Applications | Transmission substations, high power applications | Distribution networks, frequent switching applications |
The choice between VCB and SF6 breakers depends on specific application requirements, environmental considerations, and system voltage levels. Zhejiang Diji Power offers expertise in both technologies to help you select the optimal solution.
SF6 Circuit Breaker Maintenance
Maintenance Guidelines
SF6 Gas Monitoring
Regular checks of gas pressure, density, and quality. Replenish gas when pressure falls below recommended levels.
Leak Detection
Periodic inspection using leak detection equipment to identify and address any SF6 leakage.
Operating Mechanism
Inspection, lubrication, and testing of spring mechanisms, hydraulic systems, or pneumatic components.
Mechanical Characteristics Testing
Measuring opening/closing times, velocity, and synchronization across phases.
SF6 Circuit Breaker Lockout Mechanisms
SF6 circuit breakers incorporate multiple safety interlocks to prevent hazardous operations:
Low Gas Pressure Lockout
Prevents operation when SF6 pressure falls below safe levels, avoiding internal flashovers.
Spring Charge Interlock
Ensures the breaker cannot close unless the opening spring is properly charged.
Truck Position Interlock
For withdrawable designs, prevents operation unless the breaker is in the proper position.
SF6 Gas Filling Procedure
Proper SF6 handling is essential for both equipment longevity and environmental protection. The SF6 gas filling procedure must be performed by qualified personnel following these steps:
- Evacuation of moisture and air from the circuit breaker
- SF6 gas quality verification before filling
- Proper connection of gas handling equipment
- Controlled filling to achieve specified pressure
- Leak testing after gas filling operations
- Documentation of gas quantity and pressure values
Our technical experts can provide detailed guidance on safe gas handling procedures and the specialized equipment required.
SF6 Circuit Breaker Maintenance
Comprehensive presentation covering SF6 technology, design principles, and application guidelines for engineers and technicians.
Detailed procedures for routine and preventive maintenance of SF6 circuit breakers with troubleshooting guides.
Comprehensive presentation covering SF6 technology, design principles, and application guidelines for engineers and technicians.
Contact Us for Expert Solutions & Quotations
Frequently Asked Questions
A: An SF6 circuit breaker is a high-voltage electrical protection device that uses Sulphur Hexafluoride (SF6) gas to extinguish electrical arcs during a fault. Its primary role is to protect critical and expensive equipment within power substations (from 40.5kV to 252kV and higher) by safely interrupting dangerous short-circuit currents.
A: The main advantages are:
- Superior Performance: Excellent arc-quenching ability allows for interrupting very high fault currents.
- Compact Design: SF6’s high dielectric strength means breakers can be smaller than air-blast alternatives, saving valuable substation space.
- High Reliability & Long Lifespan: Our breakers are designed for a mechanical life of over 10,000 operations with minimal maintenance.
- Enhanced Safety: SF6 is non-flammable, eliminating the fire risk associated with older oil-filled circuit breakers.
A: Both are excellent technologies. The key difference is the application range:
- VCBs are ideal for medium-voltage applications (typically up to 38kV) due to their compactness and high number of operations. Learn more about our VCBs.
- SF6 Breakers are the dominant technology for high-voltage (HV) and extra-high-voltage (EHV) applications (40.5kV up to 800kV) because SF6 gas’s insulating and arc-quenching properties scale much better at higher voltages.
A: To specify the correct breaker, you need to provide three key parameters:
- Rated Voltage (kV): The system’s operating voltage (e.g., 69kV, 132kV, 220kV).
- Rated Continuous Current (A): The normal operating current of the line.
- Rated Short-Circuit Breaking Capacity (kA): The maximum fault current the breaker must be able to interrupt. Our engineering team is ready to assist you in selecting the optimal and most cost-effective solution. Contact us for a technical consultation.
A: Our SF6 circuit breakers are designed, manufactured, and type-tested in strict accordance with IEC 62271-100 standards. We can provide all necessary type test reports (e.g., KEMA, CESI) upon request to ensure full compliance with your project’s technical specifications.
A: Lead time varies depending on the model and project complexity, typically ranging from 6 to 12 weeks. All our SF6 circuit breakers come with a standard 24-month warranty from the date of commissioning or 30 months from the date of shipment, whichever comes first.
A: Pure SF6 gas is inert, non-toxic, and non-flammable, making it safe to be around. However, the electric arc can create by-products. Our breakers are designed as sealed-for-life pressure systems, and all service must be performed by trained technicians using proper gas handling equipment to ensure personnel safety and prevent gas release.
A: We take this responsibility very seriously. Our strategy includes:
- Modern Design: We utilize advanced sealing technology to ensure a leakage rate of less than 0.5% per year, far exceeding industry standards.
- End-of-Life Management: We provide comprehensive guidance and services for the recovery and recycling of SF6 gas at the end of the breaker’s life, in accordance with IEC 62271-4 standards.
A: As a specialized manufacturer since 2013, we offer:
- Verifiable Quality: ISO 9001 certified facility and internationally recognized type test reports.
- Engineering Expertise: We don’t just sell products; we provide complete technical solutions tailored to your needs.
- Proven Track Record: Our breakers are reliably operating in power grids across Asia, Africa, and South America.
- Direct-from-Factory Value: You get the best combination of performance and cost by working directly with the manufacturer.
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