Protection System

The HT side of all transformers is generally protected through drop out expulsion type fuse. Three 11 kV drop out fuse units comprising a set are installed on mounting cross-arm. The fuse element is soldered on both ends among woven wires that are sufficiently strong to withstand tension while fixed to the terminals on both ends. The component is housed in an insulated tube of paper or insulating material. Horn gap fuses are also used on distribution transformers on HT side. The fuse wire is fixed among arcing horns. The benefits are that ordinary fuse wire of rated capacity could be used for replacement although for drop out fuses, fuse elements are needed to be stocked for replacement.