Cooper Bussmann NOS-40 K5 Fast-acting Fuse 40A 600V

Product Description

The COOPER BUSSMANN NOS-40 is a cartridge-style, fast-acting fuse rated at 40 amps and 600 volts AC/DC with an interrupting capacity of 50 kA. Designed for Class K5 general-purpose applications, this fuse provides overcurrent protection in industrial and commercial electrical systems. At 5.5 inches in overall length and 26.9 mm in diameter, it mounts in a standard fuse holder and is sized for high-current branch circuit and equipment protection. Electricians and maintenance technicians install this fuse in panels, disconnect switches, and motor control equipment where fast-acting response is required to protect downstream components.

This fuse is suited for general-purpose overcurrent protection in commercial and industrial settings. Typical applications include motor branch circuits, feeder panels, and equipment disconnects operating at up to 600 volts. The fast-acting response characteristic makes it appropriate for loads that do not have high inrush current demands, such as resistive loads and certain lighting circuits. It is sold individually and installed in a compatible Class K5 fuse holder.

Key Features

• 40-amp continuous current rating with fast-acting response characteristic
• 600-volt AC/DC rated for versatile use across common commercial voltages
• 50 kA interrupting capacity for high-fault-current environments
• Class K5 cartridge body fits standard K5 fuse holders
• CE Certified, CSA Certified, and UL Listed for compliance with major standards
• 5.5-inch overall length and 26.9 mm diameter for direct replacement fitment

Compatibility

Designed as a general-purpose Class K5 replacement cartridge fuse for use in standard K5-rated fuse holders rated for 600 volts and 40 amps.

Installation Notes

Installation should be performed by a qualified electrician in accordance with the National Electrical Code (NEC). Always de-energize and lock out the circuit before removing or inserting a fuse. Verify that the replacement fuse matches the amperage, voltage, and class markings of the original fuse before installation. Use an approved fuse puller when working with cartridge fuses in live or recently energized panels.