Cooper Bussmann FRN-R-100 RK5 Time Delay Fuse 100A 250V

Product Description

The COOPER BUSSMANN FRN-R-100 is a cartridge-style, time delay fuse rated at 100 amps and 250 volts with a Class RK5 designation. It features a dual-element construction that tolerates brief inrush currents — such as motor starting loads — without nuisance tripping, while still providing reliable overcurrent protection under sustained fault conditions. The bolt-on mount type and 5-7/8 inch overall length make it compatible with standard cartridge fuse holders and disconnects used across industrial and commercial electrical panels. Licensed electricians and industrial maintenance technicians are the primary installers for this type of protective device.

The FRN-R-100 is well suited for motor branch circuit protection, HVAC equipment disconnects, and general-purpose feeder protection in commercial and light industrial applications. Its time delay characteristic makes it a common choice where motor starters, compressors, or transformer inrush must be accommodated without sacrificing fault clearing speed. The dual-element design handles cyclic or intermittent loads without degrading fuse life prematurely.

Key Features

• Class RK5 time delay cartridge fuse with 100 amp rating
• 250 volt AC rating with 20 kA DC interrupt capacity at 200 volts RMS
• Dual-element construction tolerates motor inrush and transformer surge currents
• Bolt-on mount type fits standard cartridge fuse holders and safety disconnects
• Overall length of 5-7/8 inches and diameter of 26.90 mm for direct slot fitment
• CE Certified, CSA Certified, and UL Listed for broad application compliance

Compatibility

Designed as an OEM-style replacement for Class RK5 cartridge fuse applications in bolt-on fuse holders and safety disconnects rated for 250 volts and 100 amps.

Installation Notes

Installation must be performed by a licensed electrician in accordance with applicable NEC requirements for overcurrent protective devices. Always de-energize and lock out the circuit before removing or replacing a fuse. Verify that the fuse holder is rated for the Class RK5 form factor and that the circuit voltage and amperage do not exceed the fuse ratings. Never substitute a higher-amperage fuse to resolve nuisance tripping — investigate the underlying load condition instead.