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LW9-72.5 Outdoor SF₆ Circuit Breaker
Product Summary
The LW9-72.5 outdoor SF₆ circuit breaker is engineered for 72.5kV transmission and distribution networks. Designed for high fault-interrupting capability, superior insulation strength, and long-term reliability, this breaker is widely used in substations, power plants, and overhead line protection.
With advanced self-energy arc extinguishing technology and durable porcelain bushings, it ensures stable operation in harsh environmental conditions.
Key Selling Points
High Interrupting Capability
Capable of safely breaking 31.5kA short-circuit current, even under severe conditions.
Highly Reliable Operation
Three-phase linked spring mechanism ensures precise synchronized opening and closing.
Built for Harsh Environments
Long creepage distance, corrosion-resistant galvanized steel structure, and stainless steel mechanism housing.
Low Maintenance Design
SF₆ gas chamber shares pressure across all poles, with pointer-type density monitoring for peace of mind.
Excellent Performance for Frequent Switching
Ideal for lines requiring multiple daily switching operations.
Compact, Rigid, and Easy to Install
Preassembled base frame reduces on-site installation time.
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| Manufacturer | Weisho Electric |
| Model | LW9-72.5 / T2500-31.5 |
| Rated Voltage | 72.5kV |
| Rated Current | 2500A |
| Short-Circuit Breaking Current | 31.5kA (25kA at –45°C~+40°C) |
| Short-Circuit Making Current (Peak) | 80kA |
| Short-Time Withstand Current | 31.5kA / 4s |
| Peak Withstand Current | 80kA |
| 1-min Power Frequency Withstand Voltage | 160kV (phase-to-earth) |
| Lightning Impulse Withstand Voltage | 350kV |
| Zero-Gauge 5-min Withstand Voltage | 84kV |
| Main Circuit Resistance | ≤50 μΩ |
| Opening / Breaking / Closing Time | ≤0.03s / ≤0.06s / ≤0.15s |
| Open-Close Interval | ≥0.3s |
| Close-Open Interval | 0.06s |
| Three-Phase Non-Simultaneity | Opening ≤0.002s, Closing ≤0.004s |
| Mechanical Life | 3000 operations |
| Moving / Sliding Contact Stroke | 150mm / 27 ± 2mm |
| SF₆ Rated Pressure (20°C) | 0.50MPa |
| SF₆ Alarm / Lockout Pressure | 0.45 ±0.02MPa / 0.40 ±0.02MPa |
| SF₆ Moisture Content | ≤150 PPM |
| Annual Leakage Rate | ≤1% |
| Gas Filling Weight | 3.5kg |
| Trip/Close Coil | DC110V / DC220V, 2.2A, 50Ω |
| Mechanism Motor | 315W, AC/DC 220V |
| Heater | 100W, AC220V |
| Terminal Strength | 500–750N |
| Creepage Distance | Pollution III: 2090mm gap / 1815mm earth; Pollution IV: 2585mm gap / 2250mm earth |
| Ambient Temperature | –30°C to +40°C |
| Altitude | ≤1000m (custom >1000m) |
| Wind / Ice / Seismic | Wind ≤35 m/s; Ice ≤10mm; Horizontal ≤0.4g, Vertical ≤0.2g |
| Max Daily Temperature Difference | 25°C |
| Applications | Transmission line protection, Substation bays, Transformer protection, Capacitor bank switching, Industrial HV systems |
| Optional / Custom | Remote monitoring, Additional contacts, Custom creepage distance, Manual/Electric operation, Control voltage customization |
| Key Selling Points | High interrupting capability, Low maintenance, Anti-corrosion structure, High insulation, Frequent operation support |
Technical Features
1. Arc-Quenching & Insulation
SF₆ gas serves as both an insulating and arc-extinguishing medium.
Self-energy (auto-puffer) arc-quenching principle increases breaking efficiency.
No restrike when breaking capacitive currents.
2. Mechanical Structure
Three-phase porcelain-column design with a single break per pole.
Centralized CT26 spring operating mechanism with long mechanical life (3000 operations).
Optimized linkage reduces operating force and mechanical wear.
3. Anti-Corrosion Construction
Hot-dip galvanized steel base and brackets.
High-strength, hot-dip galvanized hardware.
Stainless-steel mechanism cabinet for outdoor durability.
4. Environmental Suitability
Supports –30°C to +40°C ambient temperature.
Suitable for high-pollution areas (Pollution Class III–IV).
Withstands 35m/s wind speed, 10mm ice load, and 0.4g seismic acceleration.
5. Electrical Reliability
Long electrical endurance with minimal SF₆ gas replacement.
Maintains ≤50µΩ main circuit resistance.
Capable of withstanding repetitive switching under full load.
Applications
This circuit breaker is suitable for:
72.5kV substations
Transmission & distribution line protection
Transformer protection
Power plants
Reactive power compensation systems
Industrial power distribution networks
Capacitor bank switching (optional configuration)
Optional Accessories & Customization
Available upon request:
Motorized/manual spring mechanism options
Auxiliary contacts (up to +10 pairs)
Anti-condensation heater
Position indication switches
Remote monitoring/telemetry interface
SF₆ gas density sensor (digital output)
Customized creepage distance for high pollution areas
Alternative control voltages (48V, 110V, 220V AC/DC)
Why Choose Weisho Electric
Professional HV Equipment Manufacturer
Decades of experience producing SF₆ switchgear and HV protection products.
Strict Quality Control
Each unit undergoes full routine tests, including:
Power frequency withstand tests
Lightning impulse tests
Vacuum leak tests
Mechanical operation tests
Temperature rise test (as required)
Global Export Experience
Products are widely used in Africa, Southeast Asia, the Middle East, and South America.
Customization Capability
Engineers can adjust bushings, mechanisms, CT ratios, auxiliary devices, and terminal configurations.
Fast Delivery & Complete After-Sales Support
24/7 technical support and spare parts available worldwide.
Frequently Asked Questions (FAQ)
1. What is the typical delivery time?
Standard lead time is 25–35 days, depending on quantity.
2. Can the breaker be used in high-altitude regions?
The standard model supports ≤1000m altitude.
Higher-altitude versions can be customized.
3. Does the breaker come filled with SF₆ gas?
Yes, breakers are shipped fully assembled and pre-filled with SF₆ gas.
4. Can Weisho provide a test report or Type Test Certificate?
Yes, routine test reports are supplied. Type tests are available upon request.
5. Is remote operation supported?
Yes. The CT26 spring mechanism supports remote control via SCADA/RTU.
6. What is the expected service life?
Designed for 20–30 years under normal operating conditions.
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