Industry overview

The drop-out fuse is installed on the branch line of the 10kV distribution line, which can reduce the power-off range. Because it has an obvious disconnection point, it has the function of the isolating switch, which creates a safe working environment for the maintenance section line and equipment. The safety of the maintenance personnel. Installed on the distribution transformer, it can be used as the main protection of the distribution transformer, so it has been popularized in 10kV distribution lines and distribution transformers. .

Solution

In the actual 10kV line system and the fuse on the distribution transformer can not operate correctly, one of the reasons is that the electrical quality is poor, the responsibility is not strong, and the maintenance and overhaul of the drop fuse are not carried out all the year round; the second reason is The product of the drop fuse is inferior and cannot be flexibly pulled and operated. Two reasons reduce the function of the drop fuse. In reality, there is often a case where a melted tube, a lack of melt, or a copper wire, an aluminum wire, or even a wire hook is used instead of a melt. The trip rate of the line and the failure rate of the distribution transformer are kept high.

Drop fuse

The 10kV drop-out fuse is suitable for outdoor environments where the ambient air is free of conductive dust, non-corrosive gas, and flammable, explosive, and the annual temperature difference is within ±40 °C. The choice is based on the rated voltage and rated current, that is, the rated voltage of the fuse must match the rated voltage of the protected equipment (line). The rated current of the fuse device shall be greater than or equal to the rated current of the melt. The rated current of the melt can be selected to be 1.5 to 2 times the rated load current. In addition, the selected fuse should be checked for the three-phase short-circuit capacity of the protected system. Ensure that the three-phase short-circuit capacity of the protected system is less than the upper limit of the rated disconnect capacity of the fuse, but must be greater than the lower limit of the rated disconnect capacity. If the rated breaking capacity of the fuse (generally the upper limit) is too large, it is likely that the three-phase short-circuit capacity of the protected system is less than the lower limit of the rated breaking capacity of the fuse, which makes it difficult to extinguish the arc when the melt is blown, eventually causing The fuse is burned, exploded, etc.