The hottest Pearl River cable tells you why you ca

2022-10-03
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[Zhujiang cable] tells you why you can't choose aluminum alloy cable

on December 4 this year, aluminum alloy cable has not been used for a long time in China, but there have been cases that show that aluminum alloy cable has great hidden dangers and risks when it is used in cities, factories and mines, and users lack understanding of the basic performance of aluminum alloy cable, so they have suffered huge losses, If users know the characteristics of aluminum alloy cables in terms of fire reliability and corrosion prevention in advance, such losses can be avoided in advance

judging from the characteristics of aluminum alloy cables, aluminum alloy cables have natural defects in fire prevention and corrosion prevention. It is shown in the following six aspects:

1. Corrosion resistance of aluminum alloy is even inferior to that of ordinary aluminum

gb/t19292 Reduce some cumbersome and complex physical labor. Note 4 of Table 1 of the 3 standards states that the corrosion resistance of aluminum alloy is worse than that of ordinary aluminum and worse than that of copper. This is because magnesium, copper, zinc and iron elements are added to aluminum alloy cables. Therefore, the project only takes 210 days from commencement to production, which is prone to local corrosion, such as stress corrosion fracture, layer corrosion and intergranular corrosion. Aluminum alloy cables add heat treatment procedures, which is easy to cause uneven physical state, It is easier to be corroded than aluminum cable

2. Temperature resistance: aluminum alloy is much different from copper

the melting point of copper is 1080 ℃, while the melting point of aluminum and aluminum alloy is 660 ℃, so copper conductor is a better choice for fire-resistant cables. Now some aluminum alloy cable manufacturers claim that they can produce fire-resistant aluminum alloy cables and have passed the relevant national standard tests, but there is no difference between aluminum alloy cables and aluminum cables in this regard. If the temperature in the center of a fire is higher than the melting point of aluminum alloy and aluminum cables, no matter what heat insulation measures the cables take, the cables will melt in a very short time and lose their conductive function. Therefore, aluminum and aluminum alloys should not be used as fire-resistant cable conductors, It should not be used in power distribution, buildings, factories and mines in densely populated cities

3. The coefficient of thermal expansion of aluminum alloy is much higher than that of copper

the coefficient of thermal expansion of aluminum is much higher than that of copper. A high coefficient of thermal expansion will lead to poor contact of conductors after thermal expansion and cold contraction and a vicious cycle. However, there is always a peak valley difference in power supply, which poses a great test to the performance of cables

4. Aluminum oxidation of aluminum alloy

aluminum alloy or aluminum exposed to the atmosphere will quickly form a hard, strong adhesion but fragile film with a thickness of about 10nm, which has a high resistivity. Its hardness and adhesion make it difficult to form conductive contacts, which is the reason why the surface oxide layer must be removed before the installation of aluminum and aluminum alloy. The surface of copper will also be oxidized, but the oxide layer is soft and easy to break into semiconductors under stress

5. Aluminum alloy cable connection reliability problem

there are five factors affecting the connection reliability of aluminum. Aluminum alloy has only improved on one problem, which does not solve the connection problem of common aluminum. Aluminum alloy is also a kind of aluminum, and it is not a new material. In terms of conductor performance, if the gap between aluminum and copper is not solved, aluminum alloy cannot replace copper. 6. Effective experimental width: 380mm

6. The aluminum alloy cable joint process is complex and easy to leave hidden dangers

Replenishment: in the forming conditions, the aluminum alloy cable joint process has three more processes than the copper cable. The effective removal of oxide layer and coating of antioxidant are the key. The domestic construction level and quality requirements are uneven, leaving hidden dangers

in addition to the above factors, aluminum alloy cables also have a series of professional problems, such as the lack of unified standards for current carrying capacity, the failure of connector terminals, the increase of capacitive current, the narrowing or insufficient support of aluminum alloy cable laying spacing due to the increase of cross-section, the construction difficulties caused by the increase of cable cross-section, the matching of cable trench space, the sharp rise of maintenance and risk costs, and the rise of full life cycle costs

if it is handled improperly or ignored, it is enough to let users suffer heavy and irreparable losses and accidents. To avoid these accidents, the most effective operation is to use high-quality cables with guaranteed quality: Zhujiang cable has passed the ISO9001:2008 international standard certification. By introducing advanced wire and cable manufacturing technology, production equipment, testing equipment and original imported wire drawing equipment, we can ensure that each cable produced is tested to be qualified. At the same time, we carefully select high-quality oxygen free copper as the raw material to ensure the quality of copper core from the source, The cable can avoid oxidation and high resistance, which further ensures the current carrying capacity. The cross-linked polyethylene sheath used has excellent chemical resistance and can avoid all kinds of corrosion, so it also has good environmental stress resistance. Zhujiang cable is perfect beyond aluminum alloy cable in all aspects. Such a cable is a safe cable for use

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