Cooper Bussmann FRN-R-3 RK5 Time Delay Fuse 3A

Product Description

The COOPER BUSSMANN FRN-R-3 is a Class RK5 cartridge time delay fuse rated at 3 amps, designed for general-purpose overcurrent protection in industrial and commercial electrical systems. It measures 2 inches (50.8 mm) in overall length and 14.3 mm in diameter, fitting standard cartridge fuse holders. The dual-element, time delay design allows momentary inrush currents to pass without nuisance blowing while still providing reliable protection against sustained overloads and short circuits. It carries CE, CSA, and UL listings, making it suitable for installations requiring certified components. Licensed electricians and electrical contractors are the primary installers of this fuse type.

This fuse is used in residential, commercial, and light industrial electrical distribution panels, motor branch circuits, and equipment requiring Class RK5 overcurrent protection. Its time delay characteristic makes it well suited for motor loads, transformer primaries, and other inductive loads where startup inrush current would otherwise trip a fast-acting fuse. The cartridge body mounts in a compatible RK5 fuse holder.

Key Features

• Class RK5 rating for general-purpose overcurrent protection
• 3 amp continuous current rating with time delay characteristic
• Dual-element construction tolerates inrush without nuisance blowing
• Overall length of 2 inches (50.8 mm), 14.3 mm diameter for standard cartridge fuse holder fit
• Non-indicating design
• CE Certified, CSA C22.2 No. 248.12 Certified, and UL Listed 248-12 Class RK5

Compatibility

Designed for use in standard Class RK5 cartridge fuse holders in general-purpose electrical distribution and motor branch circuit applications.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and applicable local codes. Always de-energize and lock out the circuit before removing or installing a fuse. Confirm the fuse holder is rated for Class RK5 cartridge fuses before installation. Never substitute a higher-amperage fuse or bypass overcurrent protection.