Is a copper wire with a diameter smaller than the national standard considered a non-standard cable?

For a long time, there has been a headache for cable sales, which is whether defective cables are non-standard cables. Because many customers like to measure the diameter of cable conductors to determine whether the cable is qualified. So many people are discussing whether copper wire with a diameter smaller than the national standard is considered non-standard?

Not long ago, a report issued by the authoritative agency CQC has attracted industry attention. This report also answers the question that troubles many people. With this report, sales bosses can use it to explain to customers.

What organization is CQC?

The China Quality Certification Center (CQC) is a national level certification body approved by the Central Organization Committee, established by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, and entrusted to the management of the State Administration for Market Regulation. CQC is the earliest, largest, and most authoritative certification body in China to carry out quality certification work. Over the past few decades, it has accumulated rich experience in international quality certification work, and has achieved remarkable results in various businesses. The number of certification clients ranks first among national certification bodies and among global certification bodies.

The nominal cross-sectional area of cable conductors

Nominal cross-sectional area: refers to the quantity value specified in the product standard and often used in tables. The quantity value derived from the nominal value usually needs to be verified through measurement within the specified tolerance.

From this concept, we can know that the nominal cross-sectional area is only used to describe the specifications of wires and cables, and is simply a code or name for the specifications, which facilitates production management and representation on documents.

Actual cross-sectional area of cable conductors

Actual cross-sectional area: It refers to the actual cross-sectional area of a conductor, which is the value measured by a micrometer. For wire and cable manufacturers, it refers to how large the conductor cross-section of a certain nominal cross-section is designed to meet the standard requirements, which means that the design cross-section (electrical cross-section) of this nominal cross-section must meet the standard requirements, that is, whether the DC resistance meets the standard requirements.

With the improvement of conductor material production process and scientific and technological progress today, the advanced production process of oxygen free copper materials has been widely applied. The electrical resistivity of copper conductor materials is sufficient to ensure that copper wires with a diameter smaller than the nominal diameter can meet the requirements of corresponding specifications for DC resistance.

In summary, it is common in the cable industry to have qualified DC resistance, but the actual diameter of the wire core is smaller than the nominal diameter or the actual cross-section is smaller than the nominal cross-section, which meets the requirements of product standards.

Requirements for conductor cross-sectional area in standards

At present, the product standards of major mainstream standard systems for wires and cables adopt nominal cross-sectional area or specification codes to distinguish conductors with different cross-sections. For example, IEC standards, European standards, and national standards (GB/T5023, GB/T12706, etc.).

Among them, the assessment of different cross-sectional specifications is based on the conductor resistance value, rather than the actual measurement of the conductor cross-sectional area.

Mingxin Intelligent Optics (Jiangsu) Co., Ltd. was established as a national high-tech enterprise in 2018, and the Mingxin "MX" brand was named a famous trademark in the province in 2015. The company mainly produces various types of weak current monitoring cables, YJV, YJLV