Fuse (fuse) refers to when the current exceeds specified value, the heat makes the melt fuse to itself, disconnect the circuit of a kind of electrical appliances. Fuse is according to the current more than specified value after a period of time, with its own produce hot melt melt, so that the circuit disconnection; Using the principle of a current protector. Fuse is widely used in high and low voltage power distribution system and control system and electric equipment, as a short circuit and over current protection device, is one of the most common used protection device.
Fuse is an over current protector. Fuse is mainly composed of the melt and the fusion tube and plus packing and other parts.
When using, will fuse in series to be protection circuit, when the protection circuit of the current more than specified value, and after a certain period of time, heat fusing melt produced by melt itself, make the circuit disconnect, which have the effect of protection. With metal conductor as the melt and breaking electric circuit, in series in the circuit, when overload or short circuit current through melt, melt the fever and fusing, by the power system, various kinds of electrical equipment and household appliances are played a protective effect. The time delay characteristics, when the overload current hours, melting time long; When the overload current is big, fusing time is short. Therefore, within a certain range overload current to the current back to normal, fuse not fuse, can continue to use.
Using metal conductor as melt in series in the circuit, when overload or short circuit current through melt, because of its own heat fusing, thus breaking the circuit is a kind of electrical appliances. Fuse has simple structure, easy to use, widely used in electric power system, various kinds of electrical equipment and appliances is a protective device.
 
The difference between the fuse and circuit breaker:
Similarity is to achieve short circuit protection, fuse the principle is to use the current flows through a conductor can make the conductor heating, after reaching the melting point of a conductor conductor melting so disconnect circuit protection electrical appliances and wiring is not burn out. It is a cumulative heat, so also can achieve overload protection. Once the melt burned will change of the melt. Circuit breaker can also achieve line short circuit and overload protection, but the principle is not the same, it is through the bottom of the current magnetic (electromagnetic trip) to realize open circuit protection, overload protection was achieved by the heating effect of the current (not fuse, without replacement devices). Specific to the actual, when the circuit of the electric load for a long time close to the load of fuse used, fuse gradually heat, until the fuse. As said above, fuse fusing is outcome of combined action of current and time have the effect of on line protection, it is a one-off. And the current in the circuit breaker is the circuit suddenly increase, more than the load on the circuit breaker, will automatically disconnect, it is a moment of circuit current increase the protection, such as when the leakage is large, or short circuit, or the protection of the instantaneous current is large. When find out the reason, may continue to use switching. As mentioned above, fuse fusing is the result of the combination of current and time, and the circuit breaker, as long as the current one over its set value will be tripped, time effect almost don't have to consider. Circuit breaker is low-voltage distribution commonly used components. There is also a part of the local suit with a fuse.