For high current protection zones, the selected fuse should have the following performance: ① large capacity, usually in the tens to hundreds of A; ② Capable of withstanding instantaneous high currents and pulses; ③ High safety and reliability; ④ The operating environment temperature is relatively high; ⑤ Good mechanical characteristics. 1. Selection of fuse type Select the appropriate type based on the working environment, size limitations, current characteristics, voltage characteristics, connection method, etc. of the fuse. Usually, high-voltage fuses for electric vehicles use American standard FWH, FWP, and other series. 2. Determination of fuse parameters The rated current value of fuses is usually based on the value at an ambient temperature of 23 ± 5 ℃. In order to meet the actual operating requirements of electric vehicles, it is necessary to modify the rated current value. By using the above formula, a preliminary rated current of the fuse can be obtained. However, in
For the melt, its operating current and operating time characteristics are the ampere second characteristics of the fuse, also known as the inverse time delay characteristics, that is, when the overload current is small, the fusing time is long; When the overload current is high, the fuse time is short. Our understanding of the ampere second characteristic can be seen from Joule's law that Q=I2 * R * T. In a series circuit, the R value of the fuse remains basically unchanged, and the heat generated is proportional to the square of the current I and the heating time T. This means that when the current is high, the time required for the melt to fuse is shorter. When the current is low, the melting time required for the melt to melt is longer, and even if the rate of heat accumulation is less than the rate of heat diffusion, the temperature of the fuse will not rise to the melting point, and the fuse will not even blow. So, within a certain overload current range, when the current re
The rated current of the melt is not equal to the rated current of the fuse. The rated current of the melt is selected based on the load current of the protected equipment. The rated current of the fuse should be greater than the rated current of the melt and determined in conjunction with the main electrical appliance. The fuse is mainly composed of three parts: the melt, the shell, and the support, among which the melt is a key component that controls the fusing characteristics. The material, size, and shape of the melt determine the fusing characteristics. Melt materials are divided into two categories: low melting point and high melting point. Low melting point materials such as lead and lead alloys have a low melting point and are prone to melting. Due to their high electrical resistivity, the cross-sectional size of the melt produced is larger, and the metal vapor generated during melting is more. They are only suitable for fuses with low breaking capacity. High melting poin
Spiral fuse: There is a fuse indicator on the upper cover of the melt. Once the melt melts, the indicator immediately pops up and can be observed through the glass hole on the ceramic cap. It is commonly used in machine tool electrical control equipment. Spiral type fuse. The breaking current is large and can be used for short circuit protection in circuits with voltage levels of 500V and below, and current levels of 200A and below. Enclosed fuses: Enclosed fuses are divided into two types: filled fuses and unfilled fuses, as shown in Figures 3 and 4. Fuses with fillers are generally made of square porcelain tubes filled with quartz sand and melt, with strong breaking capacity. They are used in circuits with voltage levels below 500V and current levels below 1KA. The unfilled sealed fuse packs the melt into a sealed cylinder, with a slightly smaller breaking capacity, and is used in power grids or distribution equipment below 500V and 600A. Quick fuse: Quick fuse is mainly used f
Automotive fuse holder refers to the holder for installing automotive fuses. Automotive fuse holders can be divided into: panel mounted automotive fuse holders; Lead type automotive fuse holder; Car fuse clip. Panel mounted car fuse holders are commonly used in automotive electrical appliances, such as car amplifiers, car speakers, car DVDs, etc. Wire type car fuse holders are often used on car wiring harnesses. Car fuse clips are used to install car fuses on circuit boards, making them easy to install and easy to remove. Classification of fuse holders: According to the classification of installed fuses, they can be divided into fuse box and fuse box According to the size of fuses, they can be divided into large fuse boxes, medium fuse boxes, and small fuse boxes According to material classification, it can be divided into plastic fuse boxes and bakelite fuse boxes According to environmental protection, it can be divided into environmentally friendly fuse boxes and non enviro
The rated current values usually include 100mA, 200mA, 315mA, 400mA, 500mA, 630mA, 800mA, 1A, 1.6A, 2A, 2.5A, 3.15A, 4A, 5A, 6.3A, etc. Generally, the rated current values of various fuses are provided based on customer needs and actual purposes. The nominal working voltage of a fuse, codenamed Un, is generally rated at 32V, 60V, 125V, 250V, 300V, 500V, and 600V. Fuses can be used at a voltage not exceeding their rated voltage, but are generally not approved for use in circuits with a circuit voltage greater than the rated voltage of the fuse. When the rated current is applied to the fuse, the voltage measured at both ends of the fuse when the fuse reaches Thermal equilibrium, that is, when the temperature is stabilized, is Ud. Due to the voltage drop at both ends of the fuse having a certain impact on the circuit, there are clear provisions for voltage drop in European regulations. Usually divided into cold resistance and hot resistance, cold resistance is the resistance value
MB:+86 13924633629 Ms.vicky
E-mail: waimao@xcfuse.com
Factory :
XC Electronics(Shenzhen)Corp.,LTD
Add: Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
Shenzhen branch: Shenzhen Xucheng Electronic Commerce co.Ltd
Add: 8-15 Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
