Requirements for and development of fuse-type SPD disconnector

Surge protective device (SPD) disconnectors are used to safely isolate degraded or failed SPDs from a low voltage power system. SPD disconnectors include thermal disconnectors and current disconnectors (SCDs). The requirements for SPD disconnectors are specified in IEC61643-11. However, more information is needed to design surge protection measures with SPDs for low voltage power systems. In this paper, we define the requirements for SPD disconnectors for the class II SPD. On the basis of these requirements, we developed a fuse-type disconnector for SPDs (FDS), and we report the evaluation results of the FDS and conventional SPD disconnector.