Customizable LW Series 30kV/35kV/40.5kV Outdoor High-Voltage Side-Mounted SF6 Circuit Breaker

The Customizable LW Series 30kV/35kV/40.5kV Outdoor High-Voltage Side-Mounted SF6 Circuit Breaker from Zhejiang Jingyu Technology Co., Ltd. (JYDQ) is a purpose-engineered switching device for outdoor air-insulated substations at 30kV, 35kV, and 40.5kV. Available as the LW-30, LW-35, and LW-40.5 models, this outdoor SF6 circuit breaker delivers breaking currents of 20kA, 25kA, and 31.5kA across three performance tiers sharing identical mounting dimensions and spare parts. Certified to IEC 62271-100 and GB 1984 (KEMA type-tested), the LW Series SF6 circuit breaker is designed for reliable outdoor substation operation from −30°C to +40°C in utility feeder protection, transformer incomer, bus-tie, capacitor bank, and industrial substation applications.

SF6 Arc-Quenching Technology

The LW Series outdoor SF6 circuit breaker uses a proven auto-puffer arc-quenching system. Each opening stroke drives a piston that compresses SF6 gas and directs a high-velocity blast across separating contacts, quenching the arc without external compressors or heating equipment. This self-sufficient SF6 design achieves rated breaking currents of 20kA, 25kA, and 31.5kA at 40.5kV, with peak making currents of 50kA, 63kA, and 80kA. The SF6 gas system is sealed at 0.45 MPa (absolute, 20°C), supervised by a temperature-compensated density relay with alarm at 0.43 MPa and lock-out at 0.42 MPa. Annual SF6 leakage is ≤0.5%; gas filling uses a DILO-compatible coupling. The side-mounted motor-driven spring mechanism stores energy in ≤15 seconds via a 750W AC/DC 220V motor, with opening time ≤0.07s and closing time ≤0.1s, supporting the standard O-0.3s-CO-180s-CO auto-reclose sequence.

Three-Tier Performance Architecture

The Customizable LW Series SF6 circuit breaker offers three performance tiers with identical mounting footprints, mechanism interfaces, and spare parts:

• 20kA Variant — For general 30kV/35kV/40.5kV feeder protection; peak making current 50kA; cost-optimized for lightly loaded feeders.
• 25kA Variant — For industrial substation and transformer incomer applications with higher fault levels; peak making current 63kA.
• 31.5kA Variant — For bus-tie, generator circuit, and heavy-fault industrial networks; peak making current 80kA; out-of-step breaking 8kA for islanding protection requirements in distributed generation feeder applications.

All three LW Series SF6 circuit breaker variants support 400A capacitor bank switching and rated auto-reclose operations. Unlike expulsion fuse protection in distribution laterals, the LW Series SF6 circuit breaker provides reclosable relay-coordinated fault isolation without consumable replacement, reducing operational maintenance in feeder protection schemes. Fleet operators benefit from identical spare parts across all three performance tiers.

Outdoor Environmental Design

The LW Series SF6 circuit breaker is rated for continuous outdoor service: ambient −30°C to +40°C; altitude 1,000m standard (to 3,000m with correction); seismic 8 degrees/0.25g; wind 35 m/s; ice 10mm; pollution Class III/IV. Weather-grade porcelain interrupter insulators resist UV, industrial pollution, and salt fog. Creepage distance options reach 1,256mm (31mm/kV at 40.5kV) for heavy-pollution coastal, chemical, or desert installations. The hot-dip galvanized steel frame provides corrosion protection across the LW Series circuit breaker's 30-year design life. The side-mounted mechanism places the motor, coils, auxiliary contacts, and manual charge port at ground-accessible height, eliminating elevated work platforms for maintenance. When metal oxide varistor-based surge arresters are co-located in the substation, the 185kV lightning impulse withstand rating of the LW Series SF6 circuit breaker confirms insulation coordination with IEC 62271-1 requirements for 40.5kV outdoor substations.

Key Technical Specifications

Application Scenarios

Outdoor Substation Feeder and Transformer Protection

The LW Series 30kV/35kV/40.5kV SF6 circuit breaker is the primary device for feeder, transformer incomer, and bus-tie positions in outdoor AIS substations. Rated for 1,600A and 2,000A continuous current and interruption to 31.5kA, this SF6 circuit breaker protects overhead transmission lines, power transformers, and capacitor banks with the auto-reclose sequence required for coordinated feeder relay protection at 35kV and 40.5kV.

Industrial Substation and Grid Modernization

In steel mills, chemical plants, and mining substations, the LW Series SF6 circuit breaker provides reliable protection under dust, humidity, and temperature extremes that degrade oil-insulated equipment. For grid modernization programs, the LW Series 30kV/35kV/40.5kV SF6 circuit breaker serves as a direct retrofit for aging oil circuit breakers — eliminating oil hazards, reducing fire risk, and delivering IEC 62271-100-certified SF6 interruption performance. The 31.5kA variant's islanding protection capability safely disconnects distributed generation sources from the 35kV grid under fault conditions.

Quality Assurance and Factory Testing

Manufactured under ISO 9001, this outdoor high-voltage SF6 circuit breaker carries type-test certification to IEC 62271-100 and GB 1984, witnessed by KEMA-accredited laboratories. Each unit shipped includes factory acceptance test documentation: power-frequency withstand at 95kV, lightning impulse at 185kV, SF6 gas tightness, contact resistance, full-travel timing, and partial discharge screening. This test record supports grid connection approval and utility tender qualification for the LW Series outdoor SF6 circuit breaker.

Commercial Terms

Product Images

FAQ

1. Can SF6 circuit breaker cut off transformer magnetizing current?

Yes. SF6 circuit breaker has excellent arc extinguishing performance, it can reliably break transformer magnetizing current and inductive load current in high voltage system.

2. What is the mechanical life of SF6 circuit breaker?

The mechanical operation life is designed in accordance with IEC standard. The mechanism can completelarge amount of normal opening and closing cycles without performance degradation.

3. Can SF6 circuit breaker be installed in outdoor substation?

Yes. The whole machine is designed for outdoor installation. The shell is sealed to resist rain and dust for long term outdoor running.

4. What technical assistance can your team offer during warranty?

Our engineers provide remote fault signal analysis and troubleshooting guidance for equipment during the 10-year warranty period.