The earliest fuse in more than one hundred years ago by Edison, due to the time of the industrial technology developed incandescent bulbs are very precious, so, the original is with a fuse to protect it expensive incandescent bulbs. Fuse to protect electronic equipment with current damage, also can avoid electronic equipment serious damage caused by internal fault. Accordingly, each fuse is rated specifications, when the current exceeds the rated specification fuse will fuse. When between conventional not fuse current and relevant standards stipulated by the rated breaking capacity of (current) between the current applied to fuse, the fuse should be able to work satisfactorily, and will not endanger the environment.

Fuse is placed expected fault current of the circuit must be smaller than the standard stipulated in the current breaking capacity rating, otherwise, when the failure blown fuse continuous arcing, ignition occurs, the fuse burned, along with contact element melting, fuse the phenomenon such as tag can't identify. And, of course, the inferior fuse breaking ability can not reach the requirements of the standard, when using the same damage will happen.