Cooper Bussmann FRS-R-6-1/4ID Time Delay Fuse 6.25A RK5

Product Description

The COOPER BUSSMANN FRS-R-6-1/4ID is a general-purpose, time-delay cartridge fuse rated at 6.25 amps in the RK5 class. It features a dual-element design that tolerates brief inrush currents without nuisance tripping while still providing reliable overcurrent protection. The fuse body measures 5 inches in overall length and 0.81 inches in diameter, fitting standard RK5-compatible fuse holders. With an interrupting rating of 20 kA at DC 200 volts RMS, it is suited for circuits where downstream equipment generates startup surges. Licensed electricians and industrial maintenance technicians install this fuse in panel boards, disconnect switches, and equipment control circuits.

This fuse is intended for general-purpose electrical protection in residential, commercial, and light industrial applications. Its time-delay characteristic makes it well suited for motor branch circuits, HVAC equipment, and other loads with high inrush current at startup. The RK5 fuse class designation means it installs in any fuse holder or block rated for Class RK5 or Class K5 cartridge fuses of the same physical size. The indicating feature provides a visual confirmation of a blown fuse, which speeds up troubleshooting during service calls.

Key Features

• Time-delay, dual-element construction tolerates motor inrush without nuisance tripping
• 6.25-amp rating with 20 kA interrupting capacity at DC 200 volts RMS
• Indicating design gives visible blown-fuse confirmation
• RK5 class fuse mounts in standard cartridge fuse holders
• CE Certified, CSA C22.2 No. 248.12 Certified, and UL Listed 248-12 Class RK5

Compatibility

Designed as an OEM-style replacement cartridge fuse for Class RK5 fuse holders and disconnect blocks accepting a 5-inch by 0.81-inch cartridge fuse body.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and any applicable local codes. Always de-energize and lock out the circuit before removing or installing a fuse. Use an appropriate fuse puller rated for the voltage class of the circuit. Verify the replacement fuse rating matches the circuit design before restoring power.