High voltage current limiting fuse is applicable to indoor AC 50Hz, rated voltages of 3.6KV, 7.2KV, 12KV, 24KV, 40.5KV, rated currents of 0.5 and 2, 3, 5, 7.5, 10A systems, and is applicable to protecting the overload and short circuit faults of outdoor 35KV voltage transformers and power lines. It can be used together with other switching devices, such as load switches and real contactors, as a protective element for short circuit and overload of power transformers and other backup devices, and is also a necessary supporting product for high-voltage switch frames, ring network frames, and high/low-voltage prefabricated substations. High voltage current limiting fuse has limited current and rapidity. The peak value of fault current often appears half wave. When the bridge body is disconnected, all short circuit current will be transferred to the high-voltage current limiting fuse. The internal short circuit current of the fuse will vaporize, break down, generate arc between gaps and extinguish the arc in the future and when it rises, limiting and forcibly cutting off the short circuit current (t ＜ 2ms), so that the current cannot reach the expected peak value of short circuit current. When the short-circuit current rises to Ip, the fuse will fuse and cut off the current. The cut-off current Ip is only about 15% of the peak value of the expected current, greatly reducing the impact of the fault current on the electrodynamic force and thermal effect of power generation and transformation equipment. The arc voltage generated by the high-voltage current limiting fuse can be limited by the nonlinear resistance, which can cooperate with the bridge resistance to solve the problem of insufficient capacity of the high-voltage current limiting fuse and improve the application range of the entire device. The fuse is composed of a melt tube, a porcelain bushing (silicone rubber insulation sheath), a fastening flange, a transverse post insulator and a terminal. Fix the terminal caps and melt pipes at both ends in the porcelain bushing by pressing, and then fix the porcelain bushing on the rod post insulator with a solid flange. The melt pipe adopts the care with high silicon oxide as the arc extinguishing medium, and the metal wire with small diameter is used as the fuse. When the overload current or short circuit current passes through the melt tube, the fuse will melt immediately. The arc occurs in several parallel narrow slits. The metal vapor in the arc penetrates into the quartz sand, is strongly dissociated, and quickly extinguishes the arc. Therefore, the fuse has good performance and large breaking capacity.1. High breaking capacity. Generally, the rated short-circuit breaking current (expected effective value) of domestic high-voltage current-limiting fuses is 50kA, and the rated short-circuit breaking capacity of some imported products reaches 63kA. 2. Current-limiting capacity, generally domestic high-voltage current-limiting fuses, such as 100A fuses, the cut-off current peak value is about 18kA when the effective value of the expected short-circuit current is 50kA, while for a certain imported 100A fuse, in When the expected short-circuit current effective value is 63kA, the cut-off current peak value is only 18kA. 3. There is a minimum breaking current. For current-limiting fuses for transformer protection, the minimum breaking current is generally 3 to 5 times the rated current of the fuse. When selecting, it should be ensured that its minimum fusing current is not greater than the minimum short-circuit current of the protected circuit. 4. The power loss is small, which ensures that the product has a low temperature rise. This feature is more beneficial when the fuse is used in a fully enclosed insulation device. Low arc voltage: During the breaking process, the arc voltage is low, and when it is used in a system with a voltage lower than the rated voltage, the arc voltage will be further reduced, so that the 12KV fuse can be used in a 12KV or 7.2KV system without damaging the system insulation danger. 5. The error of the characteristic curve is small, and the error of the time-current characteristic curve is less than ± 10%, which ensures the reliability of the product. Moreover, all comply with the International Electrotechnical Commission (IEC) standard. The busbar type can be directly fastened to the busbar with screws, which has the advantages of small installation volume and reliable contact; while the plug-in type is easy to replace and can be operated with electricity.