First, drop-fuse structure and working principle
High-voltage drop-out fuse mounting plate is fixed in the middle of the support insulator. Support the insulator has the upper and lower terminals for the connection wire. Upper and lower terminals attached to the upper and lower static contact. The fuse tube is made of phenolic paper tube or laminated glass cloth tube, lined with arc-extinguishing tube; both ends are equipped with upper and lower moving contact, after the fuse penetrates the fuse tube, using the tension of the fuse, , Move the contact taut so that the fuse remains closed.
When operating. Insert the lower moving contact of the fuse tube into the lower terminal with the high voltage insulated rod and make it come into contact with the lower stationary contact, then insert the pull hook of the high voltage insulated rod into the operating ring of the fuse tube to drive the fuse tube The upper moving contact pushed into the terminal, contact with the static contact, the circuit connected.
After the fuse is blown The upper and lower movable contact of the fuse tube loses the tension and loosens, the movable contact slides downward under the action of the spring, the fuse tube falls by its own weight, the fuse is in the disconnected state, and the obvious fracture occurs
When a line or device fails. The fault current causes the fuse to fuse quickly and create an arc. Arc extinguishing tube produces a lot of gas under the action of the electric arc, so that the tube to form a great pressure, the gas jet out at high speed, this powerful air flow, the arc quickly elongated and extinguished.
Second, the operation of drop-out fuse, should pay attention to the matter:
1, the operation should wear protective color glasses, so as to avoid failure to pull, a total of arc burns eyes; at the same time stand a good position, the operation decisive quickly, moderate force to prevent the impact of damage porcelain.
2, together, the first joint on both sides (that is, both sides), after the middle phase. When opened, first open the middle phase, then open both sides (ie, both sides).
3, does not allow with load operation.
Third, the installation of high-voltage fuse technical requirements:
1, the fuse tube must be tightly inserted into the jaws;
2, with the motion indicator fuse tube, the indicator should be installed down;
3, melt specifications must meet the design requirements, may not have broken and damaged;
4, fuse tube should be free from cracks or damage.
Fourth, drop-fuse installation of the technical requirements:
1, drop fuse base (bracket) and parts of the parts should be complete, fixed and solid, three-phase fulcrum in the same plane.
2,10 KV drop-out fuse horizontal distance should not be less than 500mm.
Fifth, drop-type fuse installation should meet the following requirements:
(1) Contact shaft smooth and flexible, the casting should not have cracks, trachoma, rust.
(2) should be clean inside the fuse, fuse installation should be properly tightened, screwed firmly. Copper braided wire at both ends of the fuse should not be screwed, grams broken.
(3) Fuse installed securely, arranged neatly, the angle between the melting tube axis and the vertical line should be 150 ~ 300. Fuse after the fuse should be flexible and reliable drop action, close contact, the upper and lower leads should be pressed, and wire connections should be close and reliable.
(4) good porcelain body, melting tube should not have moisture absorption expansion or bending phenomenon.
Six, melt specifications must meet the design requirements, and should be no bending, flattening may not have broken or damaged.