Cooper Bussmann FRS-R-1-1 Fusetron time-delay fuse is a slow-blow protective device rated at 4 A and 600 V, belonging to the RK5 class. As a time-delay (slow-blow) fuse, it tolerates short-duration overloads without immediate tripping, while reliably interrupting current on sustained overcurrents. The FRS-R-1-1 designation identifies the specific form factor within the Bussmann RK5 family, providing a compact, replaceable safeguard for electrical circuits that require RK5-rated protection at up to 600 volts.
