Material quality and characteristics are the basic factors that determine the service life of auto fuses. High-quality materials must have good electrical conductivity, aging resistance and thermal stability. For example, copper alloy materials have strong electrical conductivity, which can reduce the heat generated by resistance and reduce the risk of melting; while the uniformity and purity of the alloy composition directly affect its aging resistance. Excessive impurities can easily lead to local corrosion or oxidation, shortening the service life. In addition, the thermal expansion coefficient of the material must match that of other components, otherwise stress will be generated when the temperature changes, accelerating material fatigue and affecting the life of the fuse.
The working environment temperature has a significant impact on the life of auto fuses. High temperature environment will accelerate material aging, making the insulation layer of the fuse hard and brittle, losing elasticity, and increasing the risk of short circuit; at the same time, high temperature will also cause material performance degradation, such as lowering the melting point, so that the fuse may also melt under normal current. Low temperature environment may make the fuse material brittle, reduce toughness, and easily break when subjected to vibration or impact. In addition, frequent temperature fluctuations will cause thermal fatigue in the material and accelerate its damage process.
Current fluctuations and overload are important factors affecting the service life of auto fuses. Frequent current fluctuations can cause fuses to repeatedly be subjected to thermal stress, leading to material fatigue and shortening their lifespan. In overload conditions, currents exceeding the rated value of the fuse will generate excessive heat, accelerating fuse aging and melting. For example, excessive instantaneous current when the vehicle is started, or a short circuit fault in the circuit, can cause the fuse to overload. In addition, long periods of close-to-rated current can also reduce the fuse's service life due to heat accumulation.
Vibration and mechanical stress generated by the car during driving can cause hidden damage to the fuse. Continuous vibration may loosen the connection of the fuse, resulting in increased contact resistance, more heat generation, and accelerated aging; at the same time, vibration may also damage the internal structure of the fuse, such as wire breakage or loose solder joints. Mechanical stress, such as excessive squeezing and bending during installation, can cause cracks or deformation in the fuse material, reducing its mechanical and electrical properties, thereby affecting its service life.
Humidity and corrosive substances are important environmental threats to auto fuses. High humidity environment can easily form a water film on the surface of the fuse, causing electrochemical corrosion and destroying the material structure; at the same time, moisture may also penetrate the insulation layer, reducing its insulation performance and causing a short circuit. Corrosive substances such as road salt, industrial waste gas, and automobile exhaust will react chemically with the fuse material, accelerate the corrosion process, and reduce the electrical conductivity and mechanical properties of the fuse. For example, the high salt fog environment in coastal areas will significantly shorten the service life of the fuse.
The impact of circuit design and installation quality on the service life of the fuse cannot be ignored. Unreasonable circuit design, such as improper circuit impedance matching and lack of protection measures, will lead to uneven current distribution or abnormal increase, increasing the burden on the fuse. Poor installation quality, such as loose connection and poor contact, will increase the contact resistance, generate excessive heat, and accelerate the aging of the fuse. In addition, incorrect selection of fuse specifications, such as too large or too small rated current, will also affect its normal operation and service life.
Frequency of use and maintenance are human-controllable factors that affect the service life of auto fuses. Frequent use of vehicles will keep the fuse in working condition for a long time, accelerating its aging process. Lack of regular maintenance, such as failure to clean dust and debris in the fuse box in time, failure to check the appearance and connection of the fuse, etc., will prevent potential problems from being discovered and solved in time, shortening the life of the fuse. On the contrary, reasonably controlling the frequency of use, regularly conducting comprehensive inspections and maintenance of the vehicle, and timely replacing aging or damaged fuses can effectively extend their service life.
