First, the conductor DC resistance exceeds the standard. The copper wire of the wire and cable should be made of high-purity electrolytic copper, and the material drawn by such material is uniform and shiny. Some manufacturers use recycled copper to obtain high profits, or cut corners to reduce the copper wire area, resulting in serious electrical conductor resistance of the wire, the wire carrying capacity is greatly reduced, the conductor overheating during use, affecting the service life of the wire, posing a safety hazard.
2. The mechanical properties (tensile strength, elongation at break) of the insulating and sheathing materials are unqualified. The insulation and sheathing materials of some wire and cable use recycled plastics, and their tensile strength and elongation at break cannot meet the requirements for use. Such a cable is susceptible to breakage during stress, causing the live conductor to be exposed, causing short circuits and leakage.
3. The high-voltage cable insulation heat extension project is unqualified. The insulation heat extension of individual products has a melting phenomenon, which is likely to cause a short circuit accident at high temperatures.
The quality of wire and cable is worrying. How do consumers choose cables?
According to the staff of Baotou City Product Quality Inspection and Testing Institute, first of all, do not choose cables with too low prices, the price of finished cables can not be lower than the cost of sales. Second, we must consider the qualifications of the production enterprise. China implements 3C certification for wire and cable, and some products adopt the management of production licenses. The products of unlicensed enterprises have no quality guarantee. Finally, when purchasing a wire, request a product inspection report from the seller as much as possible. The quality of wire and cable cannot be judged by the naked eye, and only by testing can it be judged whether it is qualified.