The need to increase efficiency and reduce operating cost of shipboard DC power distribution networks results in a desire to increase the operating voltage of such installations to the medium voltage levels. Devices such as solid state bus-tie switches are an essential component of such systems, as they allow for system reconfigurations and prevent fault propagation across different sections of the system. This paper presents a scalable solid state bus-tie switch topology designed initially for low voltage power distribution networks, but easily scalable in terms of voltage and current. The use of a single active device greatly increases simplicity and reliability of the solution, and the ability to extend the current and voltage ratings has been verified on the prototypes through extensive experimental tests in parallel and series connection, respectively. Several methods for fault detection are discussed and further verified experimentally.