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For high-voltage outdoor substations, the LW36-126 SF6 Circuit Breaker delivers exceptional switching performance and long-term reliability. As a 126KV SF6 Circuit Breaker, it uses sulfur hexafluoride gas to quench arcs rapidly, minimizing contact wear and reducing maintenance intervals. This 126kV Outdoor SF6 Breaker is engineered to operate in the most demanding climates, thanks to its robust porcelain or composite insulators that provide excellent pollution withstand and seismic resilience. System designers specify this 126KV High Voltage SF6 Circuit Breaker for its compact footprint, modular construction, and full compliance with IEC 62271-100. The puffer-type interrupter, combined with a spring or hydraulic operating mechanism, ensures fast opening times and a high breaking capacity up to 40 kA. Commonly deployed in transmission grids, transformer protection, and capacitor bank switching, this breaker enhances network stability and protects critical assets from fault currents. A built‑in gas density monitor provides continuous supervision and low‑pressure alarms, while the sealed mechanism housing incorporates anti‑condensation heaters and corrosion‑resistant coatings. The design also includes an anti‑pumping device and trip‑free functionality, which prevent operator errors and extend the service life of the equipment. Routine production tests for power‑frequency withstand, SF6 moisture content, and main circuit resistance are performed on every unit, ensuring consistent quality before dispatch.
The LW36-126 SF6 Circuit Breaker adopts a three-pole gang-operated arrangement, with each interrupter chamber independently housed and filled with SF6 at a rated pressure of 0.6 MPa. Self‑blast technology reduces the energy required for arc extinction and significantly cuts SF6 decomposition by‑products, preserving gas purity over numerous operations. Control and protection circuits are routed through plug‑socket connectors inside a weatherproof cabinet, simplifying on‑site wiring and replacement. The mechanism can be selected as a motor‑charged spring system or a hydraulic drive to match different auxiliary power supplies and duty cycles. Mechanical endurance is verified up to 10,000 CO operations, and the unit withstands ambient temperatures from -40°C to +50°C without derating. A temperature‑compensated density switch triggers a first‑stage alarm and, if pressure continues to drop, a lockout that prevents tripping or closing—safeguarding the breaker and the network. Composite insulators are available for heavy pollution areas, offering up to 31 mm/kV specific creepage distance. The breaker integrates easily into both AIS and GIS layouts and supports optional IEC 61850‑compliant monitoring for remote diagnostics and condition‑based maintenance strategies.
The table below outlines the electrical and mechanical ratings of the standard outdoor 126 kV SF6 circuit breaker.
| Parameter | Value |
|---|---|
| Rated voltage | 126 kV |
| Rated frequency | 50 / 60 Hz |
| Rated normal current | 2000 A / 3150 A |
| Rated short‑circuit breaking current | 31.5 kA / 40 kA |
| Rated short‑circuit making current (peak) | 80 kA / 100 kA |
| Rated short‑time withstand current (3 s) | 31.5 kA / 40 kA |
| First‑pole‑to‑clear factor | 1.3 / 1.5 |
| Rated SF6 gas pressure at 20°C (gauge) | 0.6 MPa |
| Rated operating sequence | O‑0.3 s‑CO‑180 s‑CO |
| Mechanical endurance | 10,000 CO operations |
| Creepage distance (standard) | ≥ 25 mm/kV |
| Creepage distance (anti‑pollution) | ≥ 31 mm/kV |
| Ambient temperature range | -40°C to +50°C |
| Altitude (standard design) | ≤ 1000 m (custom higher) |
| Seismic withstand | 0.5g ground acceleration |
| Weight per three‑pole unit | Approx. 2500 kg |
Optional enhancements include integrated current transformers, surge arresters, and an advanced on‑line monitoring system that measures SF6 density, mechanism travel curves, and contact wear. Custom engineered solutions for high altitude, heavy ice loading, or aggressive coastal environments are available upon request. Every unit undergoes routine test verification of power‑frequency withstand voltage, SF6 leakage, main circuit resistance, and ventilation performance before leaving the factory.
