Whether the conductor is shiny, whether the DC resistance, the structure size of the conductor, etc. meet the requirements of the national standards, and the wire and cable products that meet the requirements of the national standards, whether they are aluminum conductors or copper conductors, are relatively bright, free of oil, and the DC resistance of the conductor is fully in line National standard, with good electrical conductivity and high safety. The copper core of the qualified copper core cable should be purple-red, shiny and soft, while the copper core of the inferior copper core wire is purple-black, yellow or white, with many impurities, poor mechanical strength, poor toughness, and slightly If it is strong, it will break, and there are often broken wires in the wire. When checking, you only need to pull out the wire by 2cm, and then rub a piece of white paper on the copper core. If there is a black substance on the white paper, it means that the copper There are more core impurities.
First of all, you can twist the insulation of the power cable wires by hand. The color and the characters are definitely bad. After twisting, the color of the thread or the words printed on the thread are often wiped off. Repeatedly bend the insulation layer. Inferior wire insulation layer is generally of poor material. After 3-4 times of bending, the insulation layer will break. In addition, the insulation layer of fake wires and cables looks very thick, but in fact they are mostly made of recycled plastics. Yes, over time, the insulating layer will age and leak. Finally, use fire to ignite the insulating layer. After leaving the open flame, it must be a low-quality wire that can spontaneously ignite.
Fine inner diameter and outer diameter
In contrast to the corresponding national and international standards, measure the outer diameter of the wire and cable and the inner diameter of the core. If the measured value obviously exceeds the allowable error, it is basically a poor quality power cable wire.