Cooper Bussmann FRN-R-70 RK5 Time Delay Fuse 70A 250V

Product Description

The COOPER BUSSMANN FRN-R-70 is a cartridge-style, time-delay fuse rated at 70 amps and 250 volts, classified as RK5 for general-purpose overcurrent protection. The dual-element design allows the fuse to tolerate harmless inrush currents from motors and transformers while still opening quickly on sustained overloads or short-circuit faults. With a 20 kA interrupting rating at DC 200 RMS, it provides reliable fault clearing in demanding service environments. Licensed electricians install this type of fuse in fusible disconnects, motor branch circuits, and distribution panels where RK5-class protection is specified.

This fuse is suited for residential and light commercial electrical systems where motor loads, HVAC equipment, or transformer circuits require time-delay overcurrent protection. The bolt-on mount type makes it compatible with standard RK5 fuse holders and disconnect blocks. Its cartridge body and 5.875-inch length fit fuse clips and holders designed for Class RK5 current-limiting fuses at 250 volts.

Key Features

• 70-amp, 250-volt rating for motor and general-purpose branch circuit protection
• Time-delay (dual-element) construction tolerates motor inrush without nuisance opening
• 20 kA interrupting rating at DC 200 RMS for reliable fault clearing
• RK5 current-limiting classification for code-compliant installations
• Bolt-on mount type for secure seating in standard fuse holders
• CE Certified, CSA C22.2 No. 248.12 Certified, and UL Listed 248-12 Class RK5

Compatibility

Designed for use in standard Class RK5 fuse holders and fusible disconnect switches rated for 250-volt cartridge fuses. Confirm holder ampere and voltage ratings match before installation.

Installation Notes

Installation must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and applicable local codes. Disconnect and lock out all power to the panel or disconnect before removing or installing fuses. Verify the fuse holder is rated for RK5 Class fuses at the appropriate voltage and amperage before insertion. Do not attempt to replace a blown fuse without first identifying and correcting the cause of the fault.