Cooper Bussmann FRN-R-1/2 RK5 Time Delay Fuse 0.5A

Product Description

The COOPER BUSSMANN FRN-R-1/2 is a Class RK5 cartridge-style time delay fuse rated at 0.5 amps, designed for general-purpose overcurrent protection in industrial and commercial electrical systems. Time delay construction allows temporary inrush currents to pass without nuisance tripping while still providing fast response to sustained overload or short-circuit conditions. The dual-element body measures 2 inches in overall length and 0.563 inches in diameter. It mounts in a standard fuse holder and is well suited for motor branch circuits, control panels, and equipment protection where harmonic or startup surges are present. Licensed electricians and industrial maintenance technicians are the typical installers.

This fuse fits residential and commercial control panel applications requiring Class RK5 overcurrent protection at low amperage levels. The 0.5A rating makes it appropriate for low-current branch circuits, instrumentation loops, and control transformer secondary protection. Its cartridge form factor drops into any standard RK5-compatible fuse holder without modification. The non-indicating body provides no visual blown indicator, so verification requires a continuity check or fuse tester during troubleshooting.

Key Features

• Class RK5 time delay construction tolerates motor inrush and startup surge currents
• 0.5A rating suited for low-current branch circuits and control transformer secondaries
• Dual-element design separates overload response from short-circuit interruption
• Non-indicating body; continuity testing required to confirm fuse status
• CE Certified, CSA C22.2 No. 248.12 Certified, and UL Listed 248-12 Class RK5
• Mounts in standard RK5-compatible cartridge fuse holders

Compatibility

Designed as a Class RK5 replacement fuse for use in standard cartridge fuse holders accepting 2-inch by 0.563-inch ferrule-style fuses rated for 0.5A applications.

Installation Notes

Installation should be performed by a licensed electrician in accordance with NEC Article 240 and applicable local codes. De-energize and lock out the circuit before removing or installing any fuse. Confirm the fuse holder is rated for Class RK5 fuses and that the amperage rating matches the circuit requirement. Never substitute a higher-rated fuse to work around repeated tripping; investigate the underlying fault condition first.