Industry experts pointed out that wires and cables are a large class of electrical products used to transmit power transmission information and realize electromagnetic energy conversion. Substandard products and inferior products have buried many hidden dangers for the normal operation of the power system.
Inferior wire and cable accident
1. Mark unqualified wires and cables
Mark unqualified wires and cables. Marking is the main way for wires and cables to identify the basic information of products. According to the standard, the main content of the mark is: product model, specification, standard number, factory name, place of origin, etc. within a certain mark interval. When the mark is unqualified, it will cause The construction personnel's identification errors may cause electrical accidents in serious cases.
2. Power cables with unqualified structural size
Wires and cables with unqualified structural dimensions. The main problem of the structure size is the thickness of the sheath and the insulation thickness. When the sheath and insulation thickness of the cable are not up to the standard, the electric resistance strength of the wire and cable will be seriously reduced, resulting in the shortening of the service life of the wire and cable, and it can lead to the wire and cable in severe cases. If it is broken down, the insulation (sheath) layer cannot provide normal protection, resulting in electrical short circuit and fire.
3. Unqualified wire and cable with tensile strength and elongation of insulation sheath before aging
Wire and cable with unqualified tensile strength and elongation of sheathed insulation before aging. The unqualified tensile strength and elongation of the insulating sheath before aging directly greatly shorten the working life of the Control Cable , and during construction or in a long-time energized environment with high temperature, the insulator is easily broken, resulting in a live conductor Exposed, there is a risk of electric shock short-circuit. The main reason for its disqualification is the use of recycled materials in order to reduce product costs, and the second is small enterprises that are not qualified for production.
4. Wire and cable with unqualified conductor resistance
Wires with unqualified conductor resistance. Conductor resistance is mainly an important indicator for assessing whether the conductor material of the wire and cable and the hiding surface meet.
When the conductor resistance exceeds the standard, the loss when the current passes through the line is increased, and the heating of the wire and cable is aggravated. The main reason for the unqualified conductor resistance is that in order to reduce the cost, the enterprise will shrink the copper which accounts for 80% of the raw material cost. Either reduce the cross-sectional area of the conductor, or use the recycled copper with too high impurities, which causes the conductor resistance of the wire and cable to be serious. Exceeding the standard, in addition to easy to cause fire during use, it will also accelerate the aging of the insulating layer covering the wire.