Cooper Bussmann FRN-R-20ID RK5 Time Delay Fuse 20A

Product Description

The COOPER BUSSMANN FRN-R-20ID is a Class RK5 cartridge time delay fuse rated at 20 amps, designed for general-purpose overcurrent protection in industrial and commercial electrical systems. The dual-element construction provides time delay characteristics that allow temporary motor inrush and transformer magnetizing currents to pass without nuisance opening, while still responding rapidly to sustained overloads and short-circuit faults. The indicating feature gives a visual signal when the fuse has opened, speeding up troubleshooting during service calls. Licensed electricians and industrial maintenance technicians are the primary installers of this fuse type.

The FRN-R-20ID is suited for motor branch circuit protection, HVAC equipment disconnect fusing, and control panel applications where RK5 Class fusing is specified. Its 2-inch overall length and 0.56-inch diameter fit standard RK5-compatible fuse holders and disconnects. The time delay characteristic makes it a common choice for protecting single-phase and three-phase motor loads in light commercial and industrial installations.

Key Features

• Class RK5 dual-element time delay construction allows motor inrush without nuisance blowing
• 20-amp rating with 20 kA interrupting capacity at DC 200 RMS
• Indicating feature provides visual confirmation of a blown fuse
• Cartridge body fits standard RK5 fuse holders and fusible disconnects
• CE Certified, CSA C22.2 No. 248.12 Class 1422-02 File 53787 Certified, and UL Listed 248-12 Class RK5 Guide JDDZ File E4273
• 2-inch OAL and 0.56-inch diameter for dimensional compatibility with RK5 holders

Compatibility

Designed for use in RK5-class fuse holders and fusible disconnects rated for cartridge fuses with a 2-inch overall length and 0.56-inch diameter.

Installation Notes

Installation and replacement of branch circuit fuses must be performed by a licensed electrician in accordance with NFPA 70 (NEC) requirements for the applicable circuit. Always de-energize and lock out the disconnect or panel before removing or installing fuses. Use a properly rated fuse puller when handling cartridge fuses to avoid arc flash exposure. Verify the replacement fuse amp rating, class, and voltage rating match the overcurrent protection design of the circuit before energizing.