How long can the polymer self-healing fuse not be damaged?

Question: How long can the polymer self-healing fuse not be damaged?
 
Answer: According to the safety regulations, the polymer self-recovery fuse must be kept at the highest voltage for 1000 hours at normal temperature and pressure without losing its PTC characteristics. The longer the polymer self-healing fuse is in operation, the harder it is to restore its resistance value, which may not meet the initial setting requirements. The residence time of each polymer self-recovery fuse varies with different fault events and types, and its service condition is one of the important factors to be considered.