Cooper Bussmann FRS-R-125 125A RK5 Time Delay Fuse

Product Description

The COOPER BUSSMANN FRS-R-125 is a Class RK5 cartridge time delay fuse rated at 125 amps with an overall length of 9.625 inches. It features a dual-element design that tolerates harmless inrush currents while providing reliable overcurrent protection for branch circuits, motor loads, and general-purpose power distribution equipment. Bolt-on mounting simplifies installation in fusible disconnect switches and panelboards. This fuse is specified by licensed electricians and industrial maintenance technicians wherever RK5 class overcurrent protection is required by code or equipment design.

The FRS-R-125 is suited for residential, commercial, and light industrial applications where motor loads or transformer primaries demand time delay characteristics to avoid nuisance opening on startup surges. Its dual-element construction allows it to carry normal inrush current momentarily while still opening quickly on sustained overloads or short-circuit faults. It installs into standard Class RK5 fuseholders and disconnect switches rated for cartridge-style fuses.

Key Features

• Class RK5 dual-element time delay design handles motor inrush without nuisance trips
• 125-amp continuous current rating for branch circuit and motor circuit protection
• 9.625-inch overall length fits standard RK5 cartridge fuseholders with bolt-on mounting
• 20 kA interrupting rating at DC 200 V RMS for fault current protection
• CE Certified, CSA C22.2 No. 248.12 Certified, and UL Listed 248-12 Class RK5 (Guide JDDZ File E4273)
• General-purpose fuse type suitable for a wide range of power distribution applications

Compatibility

Designed as an OEM-style replacement for standard Class RK5 cartridge fuseholder applications requiring a 125-amp time delay fuse with a 9.625-inch overall length and bolt-on mount.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and any applicable local codes. De-energize and lock out the circuit at the disconnect or panelboard before removing or installing the fuse. Verify the fuseholder is rated for Class RK5 cartridge fuses and confirm the circuit voltage and amperage do not exceed the fuse ratings. Never replace a fuse with one of a higher ampere rating than the circuit is designed to carry.