Are there any points that need attention in the selection of fuses?


Release Date:

2020-04-30

When it comes to fuses, most of my friends will not be unfamiliar, so as a common component equipment, the frequency of use of fuses is very high, but do you really understand the function of fuses?

When it comes to fuses, most of my friends will not be unfamiliar, so as a common component equipment, the frequency of use of fuses is very high, but do you really understand the function of fuses?

Fuses are actually electrical components connected in series in a circuit. The circuit operates on the principle of thermal fusing. To be more specific, when the circuit fails or is abnormal, as the current continues to rise, it may cause damage to various devices in the circuit, burn the circuit or even cause a terrible fire. If a fuse is installed, the situation will be completely different. When the current is too large, the fuse will blow its own parts to cut off the current, running from the protection circuit.

In this view, the fuse is equivalent to the protection of the circuit of an insurance, its importance is obvious, then the fuse selection principle and what?

      1. Determine according to different usage scenarios and parameters

When the protection object of the fuse is different, the type of fuse is also different. For example, for the protection of lighting circuits with small capacity or small power motors, RC1A series plug-in fuse should be adopted, because the melting coefficient of the melt is small, which is conducive to the over-current protection of the circuit. On the contrary, for the protection of large-capacity circuits or high-power electrical appliances, other overcurrent protection devices should be installed on the basis of fuses.

If you encounter a large expected short-circuit current circuit or flammable gas occasions, you can consider choosing a high breaking capacity of the RL series screw fuse or RT series high breaking fuse, on the contrary, you can use the RM10 series fuse.

      2. It should be well coordinated with the overload characteristics of the protected object

Most of the electrical equipment has a certain overload capacity. Under certain conditions, it is no problem to run in excess of a small amount and a short time. For example, when a high-power electrical appliance such as an air conditioner starts, the current will double, and the fuse It is necessary to adapt to this characteristic, otherwise it is also a very disturbing thing to fuse easily.

 

 

3, should prevent leapfrog fuse

There should be good coordination between fuses at all levels. Generally, the rated current of the upper-level melt is about 2 to 3 times larger than that of the next-level melt. In case of failure, the lower-level fuse will fuse first, and at the same time, the upper-level fuse can automatically recover. Otherwise, in case of leapfrog fusing, a small wire short circuit may cause a wide range of power failure accidents.

4, should pay attention to the impact of motor starting current

Considering the influence of the starting current of the motor, the fuse is generally only used as the short-circuit protection of the motor, and the thermal relay should be used for overload protection.

5. Correct matching of rated power and rated current of melt

The rated power should not be less than the rated current of the melt, and the rated breaking capacity should be greater than the short-circuit current that may occur in the circuit. Everyone must have a further understanding of the fuse. The so-called "no small matter", when selecting the fuse, it is still necessary to play a 120-point spirit, combine with the actual situation, think more and compare more, so as not to cause unnecessary trouble.

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