Cooper Bussmann NOS-20 Cartridge Fast-acting Fuse K5 20A 600V

Product Description

The COOPER BUSSMANN NOS-20 is a Class K5 cartridge fast-acting fuse rated at 20 amps and 600 volts with a 50 kA interrupting rating at AC and DC. The cartridge body measures 5 inches in overall length and 20.6 millimeters in diameter, fitting standard fuse holders designed for this form factor. It is a general-purpose fuse used in branch circuit and feeder protection applications across industrial, commercial, and mechanical trade environments. Electricians and maintenance technicians install this type of fuse where fast-acting overcurrent protection is required and where a Class K5 form factor is specified by the equipment or panel design.

The NOS-20 is suited for use in fuse holders and fuse blocks that accept Class K5 cartridge fuses in commercial and industrial electrical systems. Typical applications include motor branch circuits, distribution panels, and equipment protection where a 600-volt, 20-amp fast-acting fuse is called out. The 5-inch cartridge form factor is a common industry size found in both legacy and current equipment. This fuse is appropriate for installations governed by NEC requirements for overcurrent protection in general-purpose circuits.

Key Features

• 20-amp rating with 600-volt AC and DC capability
• 50 kA interrupting rating at AC and DC for high fault-current environments
• Fast-acting fuse timing for immediate response to overcurrent events
• Class K5 cartridge body, 5 inches in length and 20.6 millimeters in diameter
• Mounts in standard fuse holders designed for this cartridge form factor
• CE Certified, CSA Certified, and UL Listed to UL 248-9

Compatibility

Designed as a Class K5 cartridge fuse replacement for fuse holders and fuse blocks rated to accept a 5-inch, 20-amp, 600-volt fast-acting cartridge fuse.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and applicable local codes. De-energize and lock out the circuit before removing or installing any fuse. Confirm the fuse holder or block is rated for Class K5 cartridge fuses at the specified voltage and amperage before installation. Never install a fuse with a higher amperage rating than the circuit is designed and protected for.