Fuses and circuit breakers and the difference and comparison
First introduced the types and development of protective apparatus. We know that the protection of electrical appliances mainly has two kinds: one is the circuit breaker, the two is the fuse. Circuit breaker type many, from the protection of property, have a choice and the choice of type circuit breaker two categories; in addition, as well as with electric leakage protection circuit breaker. These protective devices each have their own characteristics, nature also has its shortcomings, should according to the distribution system to their specific conditions and requirements for use. Can't say the technology when the advanced and blindly choose. But the circuit breaker product and technology development is very rapid, protect the function more perfect circuit breaker is also more and more.
Come nearly 20 years, our country electrical appliances industrial development is very rapid, circuit breaker products follow the international advanced technology, the development of a variety of intelligent circuit breaker for distribution lines, provide a more perfect protection function. However, in some developed countries, and not because of the rapid development and elimination circuit breaker fuse, nor the fuse as backward or antiquated product. It is known, in Germany, France and other countries such as Siemens, abductive high United Electric Company, not only still production of fuses, also continue to develop new products, the technology also progress. From these aspects: circuit breaker is advanced protection electric appliance, and the fuse is not out of date or backward product. Should say, the two complement each other, each have their own scope of application.
The comparison of fuses and circuit breakers
They fuse and circuit breaker protection performance and other characteristics are compared, circuit breaker according to the non selection type and choice of two categories were described.
In 1, fuse
( 1) fuse main advantages and characteristics
Of good selectivity. A fuse fuse current rating as long as standard and IEC standard overcurrent selection ratio of 1.6: 1, namely the fuse rated current of not less than 1.6 times the value of the lower, as subordinate to selectively cut off the fault current
Restricted flow of good properties, high breaking capacity
The relative small size
The price is cheap
( 2) fuse major shortcomings and weaknesses
The fault must be replaced after the fuse fuse
The single protective function, only a current inverse time characteristic, overload, short circuit and earth fault with this protection
The occurrence of one phase of a three-phase motor fuse, will lead to the adverse consequences of two-phase operation, available with alarm fuse to cover, a fuse can be disconnected phase
The remote control and electric need not, knife switch, switch combination is possible
2, choose the type of circuit breaker
( 1) the main advantages and characteristics
The non selective circuit breaker has the above advantages
It has multiple protection functions, with long time delay, instantaneous, short delay and ground fault ( including zero sequence current and residual current protection ) protection, overload circuit breaker, respectively, delay large short circuit current instantaneous action and grounding fault protection, protection of high sensitivity, convenient to adjust various parameters, easy to satisfy various requirements for protection of power distribution lines. In addition, there can be a cascade protection function, has a good performance of selective action
The current product has intelligent features, in addition to the protection function, and the electric quantity measuring, fault recording, as well as an excuse to realize communication, distribution device and system centralized monitoring and management
( 2) the main problem
The price is very high, so it should only in the distribution line head and special important place in the branch route using
3, the choice of type circuit breaker
( 1) the main advantages and characteristics
The fault after disconnection, can hand reset, without the need to replace components, unless the cutting of short-circuit current after need repair
The inverse time characteristic of long time delay trip and instantaneous current tripper two section protection function, respectively, as the overload and short circuit protection, each doing his own job
The operating mechanism can realize the remote charged
( 2) the main shortcomings and weaknesses
The upper and lower than choosing type circuit breaker between the elusive selectively cut, fault current is large, easily lead to a circuit breaker instantaneous disconnection
The relative prices are slightly higher
The part of circuit breaker breaking capacity of the smaller, such as small rated current circuit breaker is arranged near the large capacity transformer position, will make the breaking capacity is not enough. It has high breaking capacity of products can meet, but the price is higher
The above information is provided in electrical switch factory, for reference only www.jiandq.com 15957745520