The influence of M-effect metal arrangment on the overload current pre-arcing time of DC current-limiting fuses

Using a M-effect metal is an efficient method to shorten the pre-arc time of current-limitinging fuse. But the M-effect can't work on high current range. the arrangment of M-effect metal have a significantly influence on the pre-arcing time of current-limiting fuse. The objective of this paper is to determine the influence of the arrangment of M-effect metal on the overload current pre-arcing time of DC current-limiting fuse. A DC test circuit is adopted to acquire the pre-arcing time with and without the M-effect metal. Six designs with different arrangments of M-effect metal are tested to determine the influence on the pre-arcing time. Experimental results show that the M-effect operation takes effect when the overload current is around two times of the rated current. If a short pre-arcing time is needed, the best arrangment of M-effect metal is in one side back on the restrict zone. Double sides or double layers designs of the M-effect metals took longer pre-arcing time than the one side design. The pre-arcing time also became longer as the M-effect metal moved away from the restrict zone.