Cooper Bussmann FRS-R-35 RK5 35A Time Delay Fuse

Product Description

The COOPER BUSSMANN FRS-R-35 is a cartridge-style, time delay fuse rated at 35 amps with an RK5 class designation. It is designed for general-purpose overcurrent protection in industrial and commercial electrical systems. The fuse features a dual-element construction that allows it to withstand short-term inrush currents — common during motor starts and transformer energization — without nuisance tripping, while still interrupting sustained overloads and short-circuit faults. Measuring 5.5 inches in length and 27 millimeters in diameter, this fuse installs in a standard fuse holder. Electricians and maintenance technicians working on motor branch circuits, HVAC equipment, and industrial control panels are the primary installers.

The FRS-R-35 is suited for time delay applications where equipment draws high inrush current at startup. Typical installations include motor control circuits, air conditioning and refrigeration equipment, compressor circuits, and industrial machinery requiring RK5-class fusing. Its dual-element design makes it appropriate for loads that require a delay before the fuse responds to temporary overcurrent conditions while maintaining fast response to short-circuit events.

Key Features

• 35-amp rating with RK5 class designation for general-purpose time delay protection
• Dual-element construction tolerates inrush current without nuisance tripping
• Cartridge body style, 5.5 inches long and 27 millimeters in diameter, fits standard RK5 fuse holders
• Non-indicating design — no visual blown indicator
• 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

Compatibility

Designed for use in standard RK5-class fuse holders accepting cartridge fuses with a 5.5-inch overall length and 27-millimeter diameter body.

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 any fuse. Verify that the fuse holder is rated for RK5-class cartridge fuses and that the replacement fuse amperage matches the circuit requirements. Do not substitute a higher-amperage fuse or bypass the fuse holder.