Class RK5 Fuses

For general-purpose applications where stronger current-limiting RK1 fuses aren't required, UL Class RK5 fuses provide modest current limitation. These fuses have a 200kA interrupting rating (IR) and are the same size as Class H and K fuses, but they also incorporate a rejection mechanism that prevents a current-limiting device from being accidentally downgraded. Their redesigned terminals guarantee a good fit with the rejection clips in Class R fuse holders, which prohibit fuses with lower interrupting capacity from being installed. They're more common in newer equipment, but they can also be used with a Class H fuse holder to update older installations from Class H or K fuses to provide better overcurrent protection. They are current-limiting devices that disconnect circuits before they are exposed to the full magnitude and duration of an overcurrent, preventing electrical harm.