Shock! 40% of the fires originated from black-core cables, and the "shrunk" copper core became the main culprit.
As the artery of power transmission, cable plays an important role in people's life. As an industry of "heavy industry and light materials", the cost of raw materials, including copper and aluminum, accounts for 80% of the cost of cables. Under the current situation of price war, many enterprises use improper methods to sacrifice quality and engage in malicious low-price competition, This has led to the endless emergence of inferior cables in the market. A survey shows that over 40% of fires originate from black-hearted cables, and copper, an important material for cable costs, has become the protagonist of black-hearted cable manufacturers.
Under the current situation that inferior cables are popular, how to distinguish inferior cables is a basic skill that every qualified purchaser needs to learn. Below, Shentong cable will popularize the security risks and identification methods of inferior cables for everyone.
Inferior cable has the following security risks:
Unqualified conductor resistance: The main reason for unqualified resistance is that the impurity of copper is too high, or the cross-sectional area of copper conductor is reduced, which will shrink the proportion of copper, thus causing the conductor resistance to exceed the standard. When the conductor resistance exceeds the standard, it will cause the cable current carrying capacity to fail to meet the requirements, causing the conductor to overload and heat up, causing a fire.
Unqualified structure size: unqualified structure size mainly refers to the insulation thickness and sheath thickness are not up to standard, in this case, the electrical strength of the cable will be seriously reduced, shorten the service life, once the cable is broken down, the sheath can not be normal protection, it will cause a fire.
Unqualified mark: the mark includes the specification, model, factory name, place of origin, etc. Once the mark is unqualified, it will lead to the wrong identification of the construction personnel and cause electrical accidents.
Unqualified tensile strength and elongation: these two unqualified items will greatly affect the service life of the cable. Under long-term power-on environment, it is easy to cause the insulator to break and the conductor to be exposed, thus causing the risk of electric shock. The main reason for this unqualified phenomenon is that non-compliant small enterprises use recycled materials in order to reduce production costs.
So how to identify inferior cable? Shen Tong cable for everyone to summarize the following points, the purchase should focus on observation:
Observe the copper core: to choose the copper core color is bright, soft, yellow and red, which means that the copper core has high purity, less impurities and good quality, and be alert to the low copper core with yellow and white.
Observe the insulation layer: mainly observe the thickness of the insulation layer, check whether there are pores visible to the naked eye in the section of the insulation layer, whether there is a phenomenon of core deviation. For wires and cables with high core deviation rate, one side of the core deviation is easy to leak. The lower the core deviation rate, the better the process is.
Observe the appearance: observe the color and skin texture. Regular wire and cable leather flat and smooth, uniform color, printed indicators of clear handwriting, not easy to erase. Take out a section of repeated bending, soft, strong fatigue resistance, no cracking is high-quality products, bending a few times on the break is inferior cable.
What are the main points of purchasing wires and cables? Let's take a look. As the main carrier of power transmission, wire and cable are widely used in electrical equipment, lighting circuits, household appliances, etc. Its quality directly affects the quality of the project and the safety of consumers' lives and property. There are many wire varieties on the market, and appropriate wires should be used according to their own power load.
What are the precautions for wires and cables? Let's take a look. Common cable faults: wire surface markings-according to national standards, the wire surface should have continuous markings of the manufacturer's name, product model and rated voltage. This helps to find the manufacturing plant in time when there is a problem during the use of the wire, and consumers should pay attention to this when buying the wire.
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