Drop type fuse is a more commonly used short-circuit protection switch, it is suitable for the air does not contain conductive dust, corrosive gas, flammable and explosive and other dangerous environment, the temperature difference does not exceed 40 degrees Celsius outdoor. When choosing a drop type fuse, it should be carried out according to its rated voltage and rated current two parameters. The rated voltage of the selected drop type fuse must match the rated voltage of the equipment to be protected, and its rated current should not be less than the rated current of the melt. Among them, the rated current of the melt is 1.5-2 times larger than the load current.
After selecting the drop type fuse, it is necessary to check the three-phase short-circuit capacity of the protected system to ensure that the three-phase short-circuit capacity is between the upper and lower limits of the rated disconnection capacity of the fuse. If the rated breaking capacity of the drop type fuse is too large, it is likely to cause the three-phase short circuit capacity to be lower than its lower limit value, resulting in the failure of the melt to extinguish the arc. The final result is that the fuse burns down and an explosion occurs.
