Cooper Bussmann FRS-R-20 RK5 Time Delay Fuse 20A

Product Description

The COOPER BUSSMANN FRS-R-20 is a cartridge-style, time-delay fuse rated at 20 amps and classified as an RK5 general-purpose fuse. It measures 5 inches in overall length and 20.6 mm in diameter, fitting standard RK5 fuse holders. The dual-element, time-delay design allows the fuse to ride through harmless temporary overloads and inrush currents while still providing fast, reliable protection against sustained overcurrents and short circuits. It carries a 20 kA interrupting rating at DC 200 (RMS), making it suitable for demanding branch-circuit and equipment-protection applications. Licensed electricians and industrial maintenance technicians are the primary installers of this component.

This fuse is used in residential, commercial, and light industrial electrical systems where RK5-class overcurrent protection is required. Typical applications include motor branch circuits, HVAC equipment circuits, control panels, and general-purpose branch circuits that benefit from time-delay characteristics to accommodate motor startup inrush currents without nuisance blowing. The cartridge body mounts in any standard RK5-rated fuse holder or fusible disconnect.

Key Features

• 20-amp RK5 class rating for general-purpose branch-circuit protection
• Time-delay (dual-element) design tolerates motor inrush without nuisance operation
• 20 kA interrupting capacity at DC 200 (RMS)
• Non-indicating cartridge body, 5 inches overall length and 20.6 mm diameter
• CE Certified, CSA C22.2 No. 248.12 Class 1422-02 certified, and UL Listed 248-12 Class RK5 Guide JDDZ File E4273
• Mounts in standard RK5 fuse holders — no tools required for fuse replacement

Compatibility

Designed for use in RK5-class fuse holders and fusible disconnects requiring a 20-amp, time-delay cartridge fuse with a 5-inch form factor.

Installation Notes

Installation and replacement must be performed by a qualified electrician in accordance with applicable NEC requirements and local codes. Always de-energize and lock out the circuit before opening any fusible disconnect or fuse holder. Verify that the replacement fuse amperage, class, and interrupting rating match the circuit requirements before reinstalling. Do not use a fuse with a higher amperage rating than the original equipment specification calls for.