High voltage fuse is widely used in the high voltage side of the outdoor voltage transformer of the small power distribution transformer and the 35 kV transformer substation. For small capacity transformers (5 ~ 50 kVA) high voltage fuse generally use 1 ~ 5 A (voltage transformer is 0.5 A). But because of its mechanical strength is small, can not withstand the high voltage drop fuse in the mechanical power and disconnect, in the actual operation process repeatedly difficult to successfully close the fuse. At present, such as to use small capacity fuse mounted on the drop type fuse tube in use, true to the protective effect of small transformer (CT), only to drop type fuse contact spring piece lashed together with wire and die. Therefore, when (voltage transformer) transformer fault weld tube fuse is blown out due to drop fuse to drop, fuse is blown out of the arc cannot be extinguished immediately, due to the role of an arc caused by falling type fuse box pipe burn have occurred. If because of the mechanical strength is not the size of the fuse, for small capacity with variable (voltage transformer) there is no protective effect.
High-voltage wall bushing of the new type of high voltage fuse is used high strength nylon plastic as a supplementary material for high voltage fuse, composite outside the high voltage fuse (fuse wrapped in plastic nylon), to increase the fuse mechanical strength to high-pressure drop insurance will continue to fuse to (see Figure 1). When the fuse when the overcurrent fusing due to, resulting in instant high-temperature arc melting at the same time, the nylon plastic melting, and thus achieve the drop type high voltage fuse rated fuse protection transformer capacity (of a voltage transformer) to.
High-voltage load switch in order to solve the above problems, the author developed the a new high-voltage drop fuse high mechanical strength of the fuse, the fuse solves the small capacity fuse mechanical strength is not enough, in addition to have a common fuse all the advantages, another increase in the mechanical strength of the fuse. The fuse can fast fuse in the rated current, and quickly makes fuse drop to extinguish the arc, to solve the use of small capacity (of a voltage transformer) transformer capacity fuse, because of the mechanical strength is not enough, for large capacity fuse burning equipment, to avoid the because of strong mechanical degree is not enough wire bundle die weld pipe joints, and the drop out fuse to drop, can not be quickly extinguished arc burn out the fuse tube.
In order to prevent the high voltage system from being affected by the fault of the voltage transformer itself or the fault of one side of the lead, the fuse protector should be installed at the primary side of the voltage transformer. But 110kV and above power distribution equipment, one side does not install the fuse, the voltage transformer usually only by isolation switch and grid connection.
High voltage insulator in order to prevent the two circuit of the voltage transformer short-circuit caused by the continuous over current burn transformer, so the voltage transformer two sides need to install low-voltage fuse.
