Cooper Bussmann FRS-R-50ID RK5 Time Delay Fuse 50A

Product Description

The COOPER BUSSMANN FRS-R-50ID is a cartridge-style, time-delay fuse rated at 50 amps with an RK5 fuse class designation. It measures 5.5 inches in overall length and 1.06 inches in diameter. The dual-element, time-delay design provides overload protection while tolerating the high inrush currents common in motor and transformer circuits. An indicating feature signals a blown condition, reducing diagnostic time on the service call. Licensed electricians and HVAC technicians install this fuse in fuse holders sized for RK5 cartridge fuses, typically within disconnect boxes, motor starters, and HVAC equipment service disconnects.

This fuse is suited for general-purpose industrial and commercial electrical applications where time-delay characteristics are required to ride through startup surges without nuisance opens. Typical installations include motor circuits, HVAC compressor disconnects, and equipment branch circuits operating on systems where reliable overcurrent protection and clear fault indication are priorities. The RK5 class rating defines the fuse's interrupting rating and physical dimensions, ensuring proper fit and coordinated protection within a listed fuse holder.

Key Features

• 50-amp time-delay rating handles motor inrush without nuisance blowing
• RK5 fuse class with dual-element construction for overload and short-circuit protection
• Indicating design provides visual confirmation of a blown fuse
• 20 kA DC interrupting rating at 200 volts RMS
• CE Certified, CSA C22.2 No. 248.12 Certified, and UL Listed 248-12 Class RK5
• Mounts in standard RK5 fuse holders for straightforward replacement

Compatibility

Designed as an OEM-style replacement for RK5-class cartridge fuse positions in standard fuse holders rated for 50-amp time-delay service.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the NEC and applicable local codes. Disconnect and lock out all power to the circuit before removing or installing any fuse. Confirm that the fuse holder is rated for RK5 cartridges and that the replacement fuse amperage matches the circuit's overcurrent protection requirements. Never replace a fuse with a higher-amperage unit to resolve nuisance openings without first diagnosing the underlying fault.