What events necessitated the time-delay feature in Murray's practical electric fuse?

momentary, harmless surges from motor start-up

The time-delay mechanism was specifically engineered to manage momentary, harmless surges that occur routinely in electrical systems, such as when equipment like motors begins to operate or other inductive loads are engaged. These brief spikes, while exceeding the continuous safe current limit, do not represent a true failure condition requiring interruption. If a fuse were designed to react immediately to these transient events, it would become impractical for normal operation, constantly requiring replacement. Therefore, Murray’s addition allowed the fuse to ride through these benign surges while maintaining protection against genuine, sustained overloads or dangerous short circuits.