Drop-out fuse and pull the load drop-out fuse is outdoor high-voltage protection of electrical. It is installed in high-voltage side of the distribution transformer or the Support Link of the distribution line as Transformers and lines short circuit, overload protection, and open, co-load current. Drop-out fuse is made by the insulating bracket and fuse tubes, static contact is installed at both ends of the insulation bracket, Moving contact installed on both ends of fuse tube, Fuse tube is composed by inner arc tube and outer phenolic paper tube or epoxy glass cloth tube. Pull load drop-out fuse can enhance flexibility auxiliary contacts and arc chute for open, co-load current.
When drop-out fuse in the normal operation, the fuse tube with fuse tension to form the closed position. When the system fails, the fault current blown fuse quickly, And form of arc, arc tube by the electric arc burning, Decompose large amounts of gas, formed a high pressure in the tube, and formed vertical wind along the pipeline, The arc was quickly stretch and elongated. After fuse blows, the moving contact lose tension and turned out, locking mechanism, release fuse tube, fuse tube drop, formed breaking Position. When pull the load, use insulating rod to pull the moving contact. At this point, the moving and the static contact is still contact. Continued pull the contact with the insulating rod, the auxiliary contacts are separated. the arc appear between the auxiliary contacts, and was stretch in the hood slit, the arc cover has gas, when the current is 0, the arc goes out.
Use and Standards
This product is used in 10 ~ 35KV distribution lines branching lines and distribution transformers primary side, For overload and short circuit protection Separation and Combination the rated load current.
The product model by JB/T8321-1996《Method of type AC high-voltage fuses》 prepared. Product parameters made by GB15166.3-1994 《high voltage fuses Expulsion fuses》standards. The standards are not clearly defined the important parameters and configuration, According to JB/DQ2139-1986《10 ~ 35KV outdoor high voltage drop fuse interim technology 》requires correction.
Conditions of Use
Ambient temperature: not higher than +40 ℃, not less than -30 ℃
Altitude: not exceed 1000m (1000m above can be corrected GB311.1-1997)
Power frequency: 50 ± 2Hz
Earthquake intensity: 7 degrees below
Maximum wind speed: 35m/s
