General Purpose current-limiting fuses are designed to interrupt the high-fault currents and also the low-fault currents down to approximately 1.6 times their continuous current rating. This fuse is defined in the IEEE Std C37.40 -1993 (3.1.57) as "A fuse capable of interrupting all currents from the rated interrupting current down to the current that causes melting of the fusible element in no less than one hour." These fuses can be used outdoors without any protecting enclosure.
