product description：

Drop-out fuses and pull-load drop-out fuses are outdoor high-voltage protection appliances. It is installed on the high-voltage side of the distribution transformer or on the branch line of the distribution line, and is used for short-circuit and overload protection of the transformer and the line, as well as the split and combined load current. The drop-type fuse is composed of two parts: an insulating bracket and a fuse tube. The static contacts are installed at both ends of the insulating bracket, and the moving contacts are installed at both ends of the fuse tube. Tube composition. The load drop type fuse is added with elastic auxiliary contacts and arc extinguishing cover to divide and combine the load current.

When the drop fuse is in normal operation, the fuse tube is tensioned by the fuse to form a closed position. When a fault occurs in the system, the fault current causes the fuse to be blown quickly and an arc is formed. The arc suppression tube is heated by the arc and decomposes a large amount of gas, which forms a high pressure in the tube and forms vertical blowing along the pipeline, and the arc is quickly elongated and extinguished. After the fuse is blown, the lower moving contact loses tension and turns down, the locking mechanism releases the fuse tube, and the fuse tube falls, forming an obvious breaking position. When the load needs to be pulled, use the insulating rod to pull open the moving contacts, at this time the active and static auxiliary contacts are still in contact, continue to use the insulating rod to pull the contacts, the auxiliary contacts are also separated, and an arc is generated between the auxiliary contacts. It is elongated in the slit of the arc extinguishing cover, and the arc extinguishing cover generates gas at the same time, and when the current crosses zero, the arc is extinguished.

Drop principle：

The fuse is fixed on the mounting frame by the mounting plate, and the fuse is connected in series in the power line during operation. During normal operation, the fuse tail makes the movable joint between the fuse tube and the moving contact tightly locked, and the fuse tube can be Under the pressure of the static contact, it is in the gate position. When a fault occurs in the power system, the fault current causes the fuse to be blown rapidly, and an arc is generated in the fuse tube. A sufficient pressure is formed in the fuse tube, and a strong vertical blow is formed along the fuse tube, so that the arc is rapidly elongated. When the current crosses zero, it is extinguished due to strong deionization. After the fuse is blown, the tension of the fuse is lost, the movable joint is released, and the fuse tube falls rapidly under the action of the spring pressure of the upper and lower static contacts and the weight of the fuse tube, forming a clearly visible isolation gap.

Features：

With good breaking characteristics, it can break the rated breaking current and various short-circuit and overload currents below, and its performance meets the requirements of the Electrotechnical Commission (IEC) standard.

Due to the use of step-by-step exhaust, the arc-extinguishing material small tube is installed in the melting tube, which reasonably solves the contradiction between large and small currents and expands the range of the lower limit current.

The fuse tube is made of steel paper and epoxy glass cloth tube, which ensures that the fuse tube has high mechanical strength and a rated breaking capacity of breaking more than three times. troublesome procedures.

The porcelain pieces, the upper and lower static contacts, and the mounting plate are all mechanically clamped. Compared with the cement pouring, it has a higher confidential strength, and there will be no breakage and loosening of the porcelain pieces. The parts are stamped parts, with strong interchangeability, which is convenient for production and maintenance.

The rigid parts adopt the hot-dip galvanizing process to ensure strong anti-corrosion performance and ensure safe and reliable operation.