Fuses

The Sure Guard ETP back-up current-limiting fuses are designed to protect overhead distribution systems and are used in series with another protective device (such as an expulsion fuse). This combination limits the high-fault current to a safe level, thus providing protection through the complete range. As its name implies, the “ETP” is for External Transformer Protection. For conventional transformers protected by expulsion-fuses cutouts, the ETP can be installed in series with the cutout. For self protected transformers, the ETP can be applied on the high-voltage bushing in series with the internal transformer expulsion fuse.

Mersen fuses for the protection of transformers and distribution lines deliver overload and short circuit protection. These current-limiting fuses will melt at current that can be as low as 1.7 times the fuse current ratings up to its maximum interrupting rating. These fuses are designed to withstand the transformer magnetizing inrush current. They have 2" (size C), 3" (size D) and 2x3" (size DD) inch diameter barrels with ferrules and are mounted in spring reinforced clips.