Bussmann FRS-R-300 Fusetron Current Limiting Fuse

FRS-R-300 is a Bussmann/Eaton Fusetron Class RK5 current-limiting fuse with a 300 A rating designed for systems up to 600 V AC (and 300 V DC). This dual-element, time-delay fuse delivers robust short‑circuit protection while tolerating brief overloads, providing a true current‑limiting response in industrial power circuits. It is a non-indicating fuse, intended for UL-listed Class RK5 fuse blocks, and carries an interrupting rating of 200 kA at 600 V AC and 20 kA at 300 V DC. The fuse’s cylindrical body measures about 2.34 inches in diameter, aligning with standard RK5 holders used in low‑voltage power distribution, motor drives, and control panels. Common applications include main disconnects, panel boards, machine controls, and other equipment where high fault-current protection is required without nuisance tripping from short surges. The FRS-R-300 sits within the long‑standing Bussmann Fusetron family, a go‑to choice for reliable current-limiting protection in industrial and commercial installations where fast interruption and clear protection characteristics are essential.