Fuses are most simple protective devices used upon a simple principle consisting in the use of fusible element - known as the fuse link - which gets heated to its melting point when a predetermined maximum current is exeeded. This opens the circuit and disconnects the protected installation or equipment from supply. The most important operating characteristic of a fuse is the dependence of the time required for the fuse link to melt on the magnitude of the current passing through the fuse, this dependence is known as the fuse time - current characteristic. ELMACO produces high rupture capacity ( HRC ) fuse links and fuse bases with voltage up to 24 KV, rated current from 6.3 Amp to 100 Amp for medium voltage fuses and up to 630 Amp for low voltage fuses, suitable for outdoor and indoor installations. The HRC fuses are used for the short circuit protection of electrical instruments, devices motors, switchboards, cable feeders and transformer circuits. The fuses and fuse bases are designed to meet the requirements of DIN 43625 , 43620 and IEC 282-1 , 269.