Drop-out fuse is a kind of protection switch commonly used for short circuit on 10KV distribution wires and distribution transformers. It is characterized by economy, convenient operation and strong adaptability. In the actual working conditions, the drop type fuse will cause various reasons to fail, in order to avoid these problems, the following measures can be taken:
First, reasonable selection of drop-out fuses and fuse elements
1, drop type fuse is suitable for outdoor environment, there should be no conductive dust, corrosive gas, flammable and explosive in the air, and the annual temperature difference should be within 40 ° C. When choosing a drop type fuse, it is necessary to choose a rated current greater than or equal to the rated current of the melt, and to ensure that the three-phase short-circuit capacity of the protected system is less than the upper limit of the open capacity of the drop type fuse, greater than the lower limit of the rated open capacity.
2. When selecting the fuse, it is necessary to ensure that the distribution transformer internal or high and low voltage outlet bushing can be quickly fused when there is a short circuit. It is also necessary to consider the fusing characteristics of the fuse and the superior protection time.
Second, the correct installation of the drop type fuse
1, when installing, the melt should be pulled tight, so as not to touch the hair hot;
2, installed on the frame to be stable and firm, there can be no shaking phenomenon;
3, the melting tube should be down 15°-30° Angle;
4, the installation height is not less than 4.5m;
5, the length of the melting tube should be adjusted moderately;
6, the distance between phases is greater than 60cm.
