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Circuit Breaker And Fuse Difference And Comparison
Sep 27, 2017

  Circuit breaker and fuse difference and comparison

  We know that in today's work production, both industrial and civil power distribution system, there is a phenomenon, that is, the use of low-voltage fuses less and less, more and more cases seem to everyone more Willing to use low-voltage circuit breaker to replace. And this is not a single phenomenon, in many distribution boxes, low-voltage circuit breakers are also gradually replace the fuse. While the fuses can only act as protection in some motors and disconnectors. In fact, for the above phenomenon, I think a lot of time is the lack of use of the circuit breaker and fuse the difference between the two, did not make the right choice. Here I am on the two to do a simple description.

  In terms of the protection performance of fuses and circuit breakers and other characteristics, the circuit breakers are described separately according to the non-selective and selective types.

  1 fuse

  (1) the main advantages and characteristics of the fuse

  ① good selectivity Up and down fuse fuse rated current as long as the GB and IEC standards meet the requirements of the overcurrent ratio of 1.6: 1 requirements, that is, the upper rated fuse current is not less than the subordinate of the value of 1.6 times, as the upper and lower level Selective cut off fault current

  ② good current limiting characteristics, high breaking capacity

  ③ relatively small size

  ④ cheaper prices

  (2) the main shortcomings and weaknesses of the fuse

  ① After the fuse has to replace the fuse fuse

  ② protection function is single, only a section of overcurrent anti-time characteristics, overload, short circuit and ground fault are used this protection

  ③ the occurrence of a phase fuse, the three-phase motor will lead to the adverse consequences of the two-phase operation, of course, can be used to send the alarm signal to make up the fuse, a phase fuse can be disconnected three

  ④ can not achieve remote control, need to switch with the electric knife, switch combinations are possible

  2 non-selective circuit breakers

  (1) main advantages and characteristics

  ① failure to disconnect, you can manually reset, do not have to replace the components, unless the need to cut off the short circuit current maintenance

  ② anti-time characteristics of the long delay release and instantaneous current release two protection functions, respectively, as overload and short circuit protection, the division of their duties

  ③ with remote control system can be achieved remote control

  (2) major shortcomings and weaknesses

  ① between the upper and lower non-selective circuit breaker is difficult to achieve selective cut off, the fault current is large, it is easy to cause the upper and lower circuit breaker are instantaneous disconnect

  ② relatively high price relative

  ③ part of the circuit breaker breaking capacity is smaller, such as the rated current smaller circuit breaker installed in the vicinity of large-capacity transformer location, will make the breaking capacity is not enough. Now there are high breaking capacity of the product can be satisfied, but the price is higher

  3 Selectable circuit breakers

  (1) main advantages and characteristics

  ① with non-selective circuit breaker of the above advantages

  ② with a variety of protection functions, a long delay, instantaneous, short delay and ground fault (including zero sequence current and residual current protection) protection, respectively, to achieve overload, circuit delay, short circuit current instantaneous action and ground fault protection, Protection of high sensitivity, easy adjustment of various parameters, easy to meet the various requirements of the distribution line protection. In addition, there may be cascading protection, with better selectivity performance

  ③ today's products with more intelligent features, in addition to protection, there are power measurement, fault records, and communication excuse to achieve power distribution devices and systems centralized monitoring and management

  (2) the main problem

  ① the price is very high, it should only be in the distribution line and the main point of the important points of the trunk use

  ② larger size

  The above is the difference between the circuit breaker (divided into selective and nonselective circuit breakers) and fuses. We can see that both have different advantages and disadvantages, and need to make a reasonable and cost-effective option according to the specific situation. Finally, according to personal experience, said the rational use of some of the fuse fuse: a correct understanding of the role of fuse in the distribution line protection and status, fuses and circuit breakers have their own characteristics, under different conditions play a role. In the low-voltage distribution complete sets of equipment and distribution box, there should be a certain number of fuse program for the distribution of designers and users to choose. I hope to be helpful.