The Schneider Electric TeSys DF3FN20 is an NFC cartridge fuse in the 22 x 58 mm form factor, rated 20 A at 690 V AC with a gG (general-purpose) fuse curve. It belongs to the TeSys fuse-disconnector range and includes a striker for local visual indication of a blown fuse. Supplied as a set of 10, this is a direct replacement for existing TeSys GS fuse-holder installations in motor control centers and distribution panels.
The 20 A rating at 690 V AC is the continuous current the fuse can carry under normal conditions without nuisance opening. The 22 x 58 mm body is a standard European fuse size, fitting the corresponding TeSys GS fuse-holder bases and most DIN-rail mounted fuse disconnectors in that footprint.