Drop type fuse is suitable for frequency 50HZ, rated voltage 35KV and below the power system, installed in the high voltage side of the distribution transformer or distribution of dry line. On the protection performance requirements is not high. The main function, it can be used in conjunction with isolating switch, instead of automatic air switch; can also be used in conjunction with the load switch circuit breaker, instead of expensive. At the same time, also has the working process of short-circuit protection, overload and isolating circuit drop type fuse.
Fuse in series with the electrical circuit, when in normal work, fuse with buttons arranged on the contact fuse tube, is equipped with a voltage release cap pressing sheet, fuse wire tail through the fuse tube pulled out, will eject plate twisting back pressure near the nozzle, is connected with the lower contact, the fuse in the pop-up plate under the action of torsion has been in a state of tension, and lock the movable joint. In the closing position in the fuse, the upper static contact downward and shrapnel outward thrust, the fuse contact is more reliable.
When a fault occurs in power system, the fault current will fuse break quickly, to generate electric arc melting tube, fuse tube produces a lot of gas under the action of the electric arc, when gas exceeds a given value of pressure, release tablet with the button head open, reduce the fuse pressure inside the tube, produced a strong go free in the current zero, the arc extinguishing. When the gas does not exceed the given pressure value, release tablet not action, current zero produces strong to free gas ejected from the nozzle ejection plate under, quickly will fuse wire tail pulled out, so that the arc extinction. Fuse, fuse tube joint release, in a static contact under spring pressure, coupled with its self-weight falling rapidly, the circuit is cut off, forming obvious breaking clearance.
