Selection and Installation Technology of SMD Fuse
June 28, 2021
Today we will introduce to you the selection and installation technology of chip fuse, let us take a look at the specific content.
The fusing current of the chip fuse is 1.5-2.0 times of the rated working current. When the electrical technical equipment is in normal use, the fuse will not blow. When the current in the circuit can exceed 5 times of its rated voltage and current, It will realize automatic fusing to play a protective role. If the fuse is not blown during normal use, it means that the current in the circuit has exceeded the rated value. Therefore, it is necessary to analyze and find the cause of the problem in time.
During the installation of the SMD fuse, you must first pull down the switch on the switchboard to cut off the power supply. It is better to use a pen to test whether there is electricity before operating. For fixing screws and washers, copper should be used, and iron should not be used for the time being, because iron is prone to rust for a long time and will cause poor contact. When tightening the fuse, do not use too much force to prevent the fuse from being flattened to reduce the cross-sectional area, rated current and fuse current, and it will not have the proper "insurance" effect.
To a certain extent, the patch fuse can't be screwed too loosely, mainly because too loose will result in excessive contact resistance of the connector and lead to errors. After the fuse has blown, find out the cause first. Users should not install at will. It is very dangerous to replace the fuse with copper wire or iron wire, because the copper wire or iron wire cannot cut off the current, which in turn will cause the wire and equipment to overheat and burn, and even cause a fire.
SMD fuse selection skills
1. Working current: First of all, we must be able to know the ignition of the circuit design chip that flows through the circuit design used in the normal current pass. Usually we need to reduce the difference of the pre-set amount, and then according to the choice has the following basic principles: that is, the normal current control must be less than the rated current and the derating factor of the product.
2. Fusing current: According to UL standard, in the case of SMD fuse (fuse), it should be twice the rated current of fast acting. But in most cases, in order to ensure a reliable fuse, we recommend that the fusing current should be greater than 2.5 times the rated current. In addition, the fusing time is very important, and the manufacturer must also be judged by referring to the fusing characteristics.
The above is the relevant introduction we brought to you. If you have any needs in this regard, you can contact us and we will serve you wholeheartedly!