Outdoor High-voltage Circuit Breaker of Transformers

Classification by Arc-extinguishing Medium

Oil Circuit Breaker: Insulating oil is used as the arc-extinguishing and insulating medium, and it is divided into 

multi-oil circuit breakers and  circuit breakers. For multi-oil circuit breakers, the oil is not only used for arc

 extinguishing but also serves as the insulating medium between phases and to the ground. The oil in  circuit breakers

 is mainly used for arc extinguishing. It has the advantages of small volume, less material consumption, and low price.

 However, it has the risks of fire and explosion and has gradually been phased out.

Sulfur Hexafluoride (SF₆) Circuit Breaker: SF₆ gas is used as the arc-extinguishing and insulating medium. It has the

 advantages of strong arc-extinguishing ability, good insulation performance, large breaking capacity, long electrical life, 

and small maintenance workload. It is suitable for outdoor substations of various voltage levels.

Vacuum Circuit Breaker: It is also applied in outdoor environments. It extinguishes the arc through a vacuum and has 

the characteristics of fast arc extinguishing speed, small contact wear, and long electrical life. It is generally used in 

outdoor power distribution systems with a voltage range of 10kV to 35kV.

Application Scenarios

Substation: As a key device in the substation, it is used to control and protect transformers, busbars, transmission lines, 

etc., to achieve the distribution and transmission of electrical energy.

Transmission Line: It is installed at positions such as the sectioning, interconnection, and terminals of the line. It is 

used to cut off and connect the current of the transmission line. When a fault occurs in the line, it can quickly cut off 

the fault current to protect the safety of the line and equipment.

Industry and Mines: In the power supply systems of large industrial enterprises, mines, etc., it is used to control and 

protect high-voltage motors, transformers, and other equipment to ensure reliable power supply during the production process.

Main Models

LW30B-126 Type: It is a 126kV outdoor SF₆ circuit breaker, which has the characteristics of compact structure, small 

footprint, and reliable operation. It is suitable for occasions such as incoming and outgoing lines of substations and 

busbar interconnections.

ZW8-12 Type: A 12kV outdoor vacuum circuit breaker, which has the advantages of small volume, light weight, and 

maintenance-free operation. It is widely used in the control and protection of overhead lines and cable lines in rural 

power grids and urban distribution networks.

LW15-252 Type: A 252kV outdoor SF₆ circuit breaker, which adopts a double-break structure and has high breaking 

capacity and reliability. It is commonly used in substations and switch stations of high-voltage transmission systems.