Cooper Bussmann FRS-R-3-1/2 RK5 Time Delay Fuse 3.5A

Product Description

The COOPER BUSSMANN FRS-R-3-1/2 is a cartridge-style, time delay fuse rated at 3.5 amps and classified under the RK5 fuse class. It is designed for general-purpose overcurrent protection in branch circuits, control panels, and motor load applications where a time delay is required to ride through harmless inrush currents without nuisance tripping. The fuse measures 5 inches in overall length with a 20.6 mm body diameter and features a dual-element internal construction. Installation is handled by licensed electricians as part of new or replacement fuse block and fuse holder assemblies in both residential and light commercial electrical systems.

This fuse is suited for use in motor circuits, HVAC equipment control panels, and industrial machinery where RK5-class protection is specified. The time delay characteristic makes it appropriate for applications where temporary overload conditions occur during startup. It mounts in a standard cartridge fuse holder and is a direct replacement option wherever a 3.5A RK5 cartridge time delay fuse is called for. Electricians and panel technicians working on equipment with inductive or motor loads will find this fuse appropriate for protecting downstream components.

Key Features

• RK5 fuse class rating for general-purpose overcurrent protection
• 3.5A amperage with time delay characteristic for motor inrush tolerance
• Dual-element construction for reliable time delay performance
• Non-indicating design with standard cartridge fuse holder mount type
• CE Certified, CSA C22.2 No. 248.12 certified, and UL Listed 248-12 Class RK5
• 5-inch overall length fits standard cartridge fuse holders

Compatibility

Designed as an OEM-style replacement for cartridge fuse holders accepting RK5-class fuses with a 5-inch overall length and 20.6 mm body diameter.

Installation Notes

This fuse is installed by a licensed electrician. Always de-energize and lockout the circuit at the breaker or disconnect before removing or installing a fuse. Use an appropriate fuse puller tool rated for cartridge fuses to avoid contact with energized components. Follow NEC requirements for fuse sizing and panel labeling after replacement.