Cooper Bussmann FRS-R-45 45A RK5 Time Delay Fuse

Product Description

The COOPER BUSSMANN FRS-R-45 is a cartridge-style, time delay fuse rated at 45 amps in the RK5 fuse class. Designed for general-purpose overcurrent protection, it provides a controlled delay that allows motors and other inductive loads to handle startup current surges without nuisance tripping. The fuse measures 5.5 inches in overall length with a 27 mm body diameter and features a dual-element internal construction. Licensed electricians and industrial maintenance technicians install this fuse in standard fuse holders wherever RK5 class protection is specified. It carries CE, CSA, and UL listings for use in compliant installations.

This fuse is suited for residential, commercial, and light industrial electrical systems where time delay protection is required for motor loads, HVAC equipment, and other inductive applications. The RK5 class rating fits standard RK5-compatible fuse holders and disconnect switches. Its non-indicating design means no visual indicator shows a blown fuse, so testing with a meter is the standard verification method during service calls.

Key Features

• 45-amp rating with time delay characteristic for motor and inductive load protection
• RK5 fuse class, compatible with standard RK5 fuse holders and disconnects
• Dual-element internal construction for accurate time delay response
• 5.5-inch overall length, 27 mm body diameter cartridge body
• Non-indicating fuse design
• CE Certified, CSA C22.2 No. 248.12 Certified, UL Listed 248-12 Class RK5

Compatibility

Designed for use in RK5-class fuse holders and disconnect switches rated for cartridge fuses with a 5.5-inch length and 27 mm diameter body. Suitable for general-purpose overcurrent protection applications in RK5-specified installations.

Installation Notes

Installation must be performed by a licensed electrician in accordance with the National Electrical Code (NEC) and any applicable local codes. Always de-energize and lock out the circuit before replacing or installing fuses. Verify the fuse holder is rated for RK5 class cartridge fuses and that the amperage matches the circuit protection requirements. Use a calibrated multimeter to confirm the fuse condition and circuit continuity after installation.