The development of dc transmission and distribution technologies are gaining traction. With renewable energy being fed to the grid constantly increasing, there is growing interest in development of dc grids. A major hindrance for their development is attributed to the lack of protection during short-circuit fault. Hybrid circuit breakers, a combination of mechanical and semi-conductor devices are understood to be the most effective method to protect dc grids against such faults. Several of such hybrid breakers are published and patented but still a practical high voltage dc breaker has not been developed. In this paper a novel modular hybrid circuit breaker is presented. This paper tries to address limitations present in existing breakers and a scalable model which can be used for both medium and high voltage dc networks is proposed.