The LW36-126T High Voltage AC SF6 Tank Circuit Breaker integrates the circuit breaker and current transformer into a single unit. The arc-extinguishing chamber is horizontally mounted inside a grounded aluminum alloy housing and is paired with a CT26-type spring operating mechanism. The design features fewer components, a simple and compact layout, and a robust, durable structure, meeting the requirements for oil-free switches. With excellent mechanical properties and high reliability, all critical components are processed using CNC machining centers. The bearings used are imported international brands (e.g., IKO, INA, SKF). The mechanical life can reach up to 10,000 operations.

This circuit breaker is suitable for outdoor high-voltage switchgear in three-phase 50Hz AC systems and is used for control and protection in 72.5 (126) kV power transmission and distribution systems. It can also be used for circuit breaker connections and for switching capacitor banks.

Structural Features

The circuit breaker uses a three-phase porcelain pillar single-break structure, with a spring-operated mechanism centrally arranged and linked across the three phases, giving it an elegant and compact appearance. SF6 gas serves as both the insulating and arc-quenching medium. During operation, the three poles of the circuit breaker are interconnected with SF6 gas, and a pointer-type density relay monitors the pressure and density of the gas.

Thanks to the use of the self-energy arc-extinguishing principle and optimization of the breaker’s mechanical system design, mechanical efficiency is greatly improved, reducing operating power to a minimum. The breaker has excellent interrupting performance and a long electrical life.

The installation base and support frame are made from high-quality steel plates, with the surface treated using hot-dip galvanizing. All exposed fasteners are made from high-strength materials, with either hot-dip galvanizing or stainless steel components. The mechanism box is made from stainless steel, providing excellent corrosion resistance and high mechanical reliability for frequent operation.

With the inherent high insulating strength of SF6 gas and optimal contact movement, the breaker is capable of interrupting capacitive currents without re-ignition. The external insulation is designed with a large creepage distance (>31mm/kV), ensuring excellent resistance to contamination, allowing it to operate safely in harsh environments.

The breaker also has a strong current-carrying capacity: under a current of 1.2 times the rated value (3150A × 1.2 = 3780A), temperature rise tests show a considerable safety margin. The product’s overall appearance is compact, making on-site installation and commissioning easy with minimal maintenance required.

Main Technical Parameters of Circuit Breaker