— The customer is in the assembly process
In other words, a certain proportion of fuses are found to be blown out occasionally in some electrified testing or inspection links during the production process of customers, and everything is normal after replacing another fuse. Does this mean that the quality consistency of this batch of fuses is not good?
Can this batch of fuses guarantee the starting quality of the whole machine?Can the replaced fuse withstand the surge current impact of switching machine several times in actual use?How should we consider and deal with this situation?
In order to solve the above problems, let’s first understand some characteristics of the fuse.
1、 What are the fuse failures.
1And wrong interruption.In this case, the fuse (piece) is fused at the crimping point or other parts, generally without serious burn marks, which is often because the fuse (piece) is too small, too thin, of poor quality or poor mechanical strength; the fuse (piece) has scars during installation; the porcelain holder is not fixed or fixed firmly; the fuse (piece) is not tightly pressed; and the fuse (piece) is not tightly pressed
It is caused by too long running time and producing copper aluminum gas film and increasing contact resistance.After adjusting and replacing the appropriate fuse (piece), put it into operation again.
In case of any of the above reasons, the
2. Overload fuse.Most of them occurred in the middle of the fuse (sheet), and there were few traces of arc burn.In this case, it is necessary to find out the cause of overload and prevent the occurrence of overload again.
3. Short circuit fusing.There are serious burns on the fuse (piece), and there are traces of arc burn on the porcelain holder of the fuse.
This may be caused by short circuit fault between zero line and phase line or between phase line and phase line.
For this kind of fuse, all the equipment and lines after the fuse should be carefully checked. After the fault point is found out and eliminated, the updated fuse (chip) can be put into operation again.However, when the end of a long low-voltage line is short circuited, the short-circuit current may be small and the fuse (chip) may not be severely burned due to the high impedance of the wire.
4Over voltage fusing.Similar to short-circuit fusing, there are severe burns on the general fuse (piece), mainly thunder It can be put into operation after finding out the causes and replacing the fuse (piece) with a new one.