Renalec IP65 DC string box is designed for PV system protection. Mainly supply protection for surge and current at solar DC side. Main components used in box included DC MCB, DC fuse, DC surge arrestor & DC isolator. MCB meets any requirement for protection against overload and short circuit. DC fuse& surge arrestor are used to protect the electric system from lighting, overload, short circuit too. DC Isolator can efficiently solve the problems of emergency disconnection, safety disconnection, machine control and moter control.