The cable quality problem is the conductor resistance is not qualified

In 2014, China's quality supervision system, industrial and commercial system, the State Grid Corporation of China and the mainstream media in China conducted supervision and spot checks on products in the wire and cable market in China in three directions: state administrative agencies, wire and cable users, and social supervision. 518 companies were notified and reported. Enterprises (excluding companies without business registration information), 859 wire and cable products have quality problems. Judging from the unqualified data, the number of unqualified conductor resistance (20°C) was the highest, which was 430 times, accounting for 25.37% of the total number of unqualified items.

According to the unqualified data of wire and cable products published in 2014, the unqualified projects involved conductor resistance, conductor tensile strength, structural size, insulation resistance, mechanical properties of insulation and sheathing, and thermal weight loss, insulation heat extension and heat shrinkage, Insulation thermal shock, flexing test, finished product voltage test, non-flammability test and cable marking.

The unqualified spot inspection quality of the 2014 annual report of wire and cable products was mainly due to conductor resistance, structural size, insulation mechanical properties, cable markings and sheath mechanical properties. Among them, the main unqualified items were unqualified conductor resistance (20°C), which was 430 times, accounting for 25.37% of the total number of unqualified items.

List of unqualified items in wire and cable products in 2014

The conductor direct current resistance (20°C) is an important indicator for assessing the conductor material of wire and cable and whether the cross-section meets the standards, and it is also an important use index of wires and cables.

The main reasons for the failure of the DC resistance of conductors are: the quality of conductor materials used by manufacturing enterprises is unqualified, such as the use of copper and aluminum containing impurities; in order to reduce production costs, production enterprises have not strictly implemented the relevant standards in the production process, and cut corners and materials, intentionally The small cross-section (larger cross section) (revenue) is used to obtain high profits, resulting in a substantial reduction in the actual cross-sectional area of ​​the conductor; too long cable storage time can lead to oxidation of the conductor surface, as well as corrosion of the conductor by certain chemical components of the insulating material. Causes the resistor to fail.

In recent years, in the field of wire and cable, the state, government, and related parties have given considerable attention. Major users such as State Grid and China Southern Power Grid urged enterprises to implement their main responsibilities and issued detailed rules for the handling of bad behaviors of supply companies. To supply companies with quality problems of untrustworthiness, they took measures such as suspension of awards, restrictions on awards, notification of rectification, and other measures. Links and social media have squeezed the living space of bad companies to the maximum extent possible. Business users and social media counter-pressed bad companies.

The results of the 2014 wire and cable sampling inspection announced by the Quality Supervision and Inspection System and the official website of the industry and commerce system, the announcement of the bad behavior of suppliers published by the State Grid in 2014, and the wire and cable violations disclosed by major social media directly reflected the quality of wire and cable market in China. . At the same time, we can clarify issues in the industry, increase public awareness of the current status of wire and cable product quality, and propose solutions, fulfill social responsibilities, provide basis for decision-making by the regulatory authorities, provide reference for enterprises to improve product quality, and provide users with consumption warnings. Help users to purchase qualified products and promote the construction of wire and cable product quality system.