A role that cannot be ignored. It can be said that wherever people live, wherever there is production, transportation and all economic activities, wires and cables are inseparable. Therefore, the quality of wires and cables has a direct impact on our lives.
Unqualified product, main problem exists in dimension of structure, conductor, conductor resistance, insulation and jacket before aging fight tensile strength, consumer used such product, extremely easy
Leakage, electric shock and even fire risk, these inferior products to the normal operation of the power system buried many hidden dangers.
One, wires and cables have single-phase grounding (short circuit) accident, relay protection device due to no action to cut off the fault caused by wire and cable overheating resulting in spontaneous combustion insulation layer.
Two, sheath insulation aging before the tensile strength, elongation qualified wire and cable, insulation sheath aging before the tensile strength, elongation is not qualified directly greatly shorten the wire
The working life of the cable, and three in the application, or in the environment of high temperature for a long time, it is easy to break the insulator, resulting in bare conductor, energy
Electric short circuit hazard.
, unqualified conductor electricity wire, conductor electricity is mainly to examine whether the conductor material of wire and cable and whether the cross section is consistent with the important indicators. When the electric voltage of a conductor exceeds the standard
It increases the loss of the current on the line, aggravates the heat of wires and cables, and the reason for the unqualified conductor electricity is mainly to reduce the cost of enterprises, which will account for the original
80% of the cost of copper material shrinkage, or reduce the cross-sectional area of the conductor, or use recycled copper containing impurities too high, so that the conductor resistance of wires and cables is seriously over
Standard, in addition to easy to cause fire in the process of use, but also accelerate the aging of the insulation coating outside the wire.
Four, wire and cable insulation layer in normal operation will gradually aging, its service life is generally 15-20 years, if the wire due to the use of time often over load or over voltage, add
The thickness of the upper insulation layer is not up to standard, improper installation (such as the bending radius of the cable is too small, the diameter of the wire protection pipe is too small), etc., may cause accidents.
Five, the structure size of unqualified wire and cable, the main problem of the structure size is sheath degree, insulation thickness, when the cable sheath and insulation thickness is not up to standard, resulting in the application
The electrical strength of wire and cable will be seriously reduced, leading to the shortening of the service life of wire and cable, serious can lead to wire and cable breakdown, insulation (sheath) layer can not be normal
Protective effect, resulting in electrical short circuit and fire and other phenomena.
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