First we must know, The amount of normal current flowing through the fuse holder fuse in the circuit being used. Usually, we need to pre-set a derating amount, and then select it according to the following principles: that is, the normal current must be less than the product of the rated current and the derating factor.

As specified, the fuse should be 2 times the rated current fast fuse in case of But in most cases, to ensure reliable fusing, we recommend that the fusing current should be greater than the rated current2.5 times. In addition, if the fusing time is important, you must also refer to the fusing characteristic diagram provided by the manufacturer to make a judgment.

The fuse in the fuse holder The open circuit voltage should generally be selected to be less than the rated voltage. For example, set the rated voltage to DC24V The fuse for AC100V In the circuit, the fuse may be ignited or ruptured. For various fuses, the rated breaking capacity is specified, and we must be careful not to make the short-circuit current exceed the rated breaking capacity when selecting a fuse. Selecting a fuse with a small breaking capacity may rupture the fuse or cause a fire.

Fuse holder surge current is also One of the factors affecting the selection of fuses, observe the waveform of the inrush current withI2tvalue (to calculate its energy. The magnitude and frequency of the inrush current are different, and the impact on the fuse is also different. The inrush current's I2tvalue and single-pulse fuseI2tThe ratio of the values ​​determines the number of times the fuse can withstand inrush current.< /p>

The fuse holder is actually used Among them, any special requirements and problems of miniature fuses in terms of installation conditions, chemical resistance, and ultrasonic cleaning resistance must be confirmed by the manufacturer in advance.