What are the hazards of unqualified wires and cables?

1、 After a single-phase grounding (short circuit) accident occurred in wires and cables, the relay protection device failed to cut off the fault, causing the wires and cables to overheat and causing the insulation layer to self ignite.

2、 Wire and cable with qualified tensile strength and elongation before aging of sheathed insulation. The unqualified tensile strength and elongation of the insulation sheath before aging directly shortens the working life of wires and cables. Moreover, during construction or in environments with prolonged electrification and high temperatures, insulation breakage is prone to occur, resulting in the exposure of live conductors and the risk of electric shock in short circuits.

3、 Wire with unqualified conductor resistance. The conductor resistance is mainly an important indicator for assessing whether the conductor material and cross-section of wires and cables meet the requirements. When the conductor resistance exceeds the limit, it increases the loss of current passing through the line, exacerbating the heating of wires and cables. The main reason for the unqualified conductor resistance is that enterprises shrink the copper material, which accounts for 80% of the raw material cost, in order to reduce costs. They either reduce the cross-sectional area of the conductor or use recycled copper with high impurities, which causes the conductor resistance of wires and cables to seriously exceed the standard. In addition to easily causing fires during use, it also accelerates the aging of the insulation layer wrapped around the wires.

4、 The insulation layer of wires and cables will gradually age during normal operation, and its service life is generally 15-20 years, If wires are frequently overloaded or overvoltage due to prolonged use, or if the thickness of the insulation layer does not meet the standard, or if they are installed improperly (such as the bending radius of the cable being too small or the diameter of the wire protection pipe being too small), accidents may occur.

5、 Wire and cable with unqualified structural dimensions. The main problem with structural dimensions is the thickness of the sheath and insulation. When the sheath and insulation thickness of the cable do not meet the standard, the electrical strength of the wire and cable will be severely reduced, leading to a shortened service life of the wire and cable. In severe cases, it can lead to the breakdown of the wire and cable, and the insulation (sheath) layer cannot play a normal protective role, resulting in electrical short circuits and fires. Shanghai Weirong Cable Co., Ltd. has always focused on the manufacturing of international standard cables, possessing over a hundred invention patents and practical patents. It is a member unit of the Shanghai Wire and Cable Research Association and has participated in the preparation of many series of special cable industry standards. The cable product variety is diverse, meeting diversified customer needs, and supporting customized solutions.