The model of high voltage circuit breaker totally includes seven parts, the meaning of each part is as follows: 

Model of high voltage circuit breaker: representing the type of circuit breaker type, represented by Letters;  Z： Vacuum circuit breaker, L: Sulfur hexafluoride circuit breaker , S: Less oil circuit breaker, D: More oil circuit breaker; 

Representing the installation place, represented by letter by N; N： Indoor type, W: Outdoor type. 

Representing the design serial number, represented by number:

Representing the rated voltage (unit KV):

The supplementary work characteristics is represented by letters; G represents improved -form, F represents operating in split-phase. 

Representing the rated current (Unit: A). Representing the rated current-breaking capacity (MVA) or breaking current(KA). 

For example, one high voltage circuit breaker with Model of ZN10-10/300-750, representing the indoor vacuum circuit breaker, the design serial number of 10, the rated voltage of 10kV, the rated current of 300 A and rated current-breaking capacity of 750 MVA.