All About Cartridge Fuses

Cartridge fuses are not a new idea. Thomas Edison patented his fuse block in 1890. A cartridge fuse is a cylinder shaped fuse with either metal caps (ferrules) or blade contact points, at both ends. The contact points are connected by a fuse link, a length of material meant to melt, or sacrifice itself, in the event of an over-current event. The melting of the fuse link severs the circuit and protects the rest of the circuit from additional damage caused by the over-current. Most cartridge fuses are rated for 250 Volt to 600 Volt circuits, dependent on the class of the fuse, and rated for varying amperages as high as 600 amps, again dependent on the specific fuse. Exceptions do apply. Additionally, cartridge fuses may be designed to be either fast acting, or time delay, again dependent on the fuse class and series. Three of today’s largest manufacturers of cartridge fuses are, Bussmann by Eaton, Littelfuse, and Mersen. FIC Corporation is proud to be an authorized distributor for these outstanding leaders in circuit protection device production.

Figure 1 Thomas A. Edison Patent No. 488,305