The D fuse-system is the first generation of screw fuse-system in the german DIN standard. It is still used in many installations. Applications are low voltage ditribution units, where non trained persons are allowed to change the fuse-links. The D fuse range comprises the sizes NDZ, DII, DIII, DIV, DV. The range of applications for D fuse-links is the protection of cables and power lines. They limit and cut-off unacceptable overcurrents and short circuit currents up to their nominal breaking capacity. D fuse-links gG also protect equipments and installations against dynamic effects of high short circuit currents.