Abstract: The commonly used series connection forms of the DC moulded case circuit breaker(MCCB) short conductor were enumerated.The advantages and disadvantages of these series connection forms were analyed.Combined with the actual improvement demand of the product,a new series structure of DC MCCB short conductor was proposed,which has the advantages of increasing the current limiting capacity,reducing the temperature rise,reducing the volume and enhancing the insulation.

Key words: moulded case circuit breaker(MCCB), direct current(DC), short conductor, series connection