1. The diameter of the copper core of a 1.5 square meter standard wire is 1.38mm.

2. The diameter of the copper core of the 2.5 square meter standard wire is 1.78mm.

3. The diameter of the copper core of the 4 square meter standard wire is 2.25mm.

A wire of 1 square mm means that the core cross-sectional area of ??a single strand (BV) wire is 1mm?, which is calculated based on the relationship between pi and diameter.

National standard wire: It is a wire produced completely in accordance with the national standard. Generally, household and common wires are of national standard specifications. The national standard has specific regulations on the appearance standards, mechanical strength, sheath insulation, wire resistance, high and low temperature impact, etc. of wires.

General wire specifications according to cross-section are: 0.75, 1.0, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120 square meters.

Extended information:

The difference between national standard wires and non-national standard wires:

1. Check whether there is a quality system certification; see whether the certificate is standardized; see Whether there is the factory name, factory address, inspection stamp, production date; check whether the trademark, specifications, voltage, etc. are printed on the wire. Also look at the cross-section of the copper core of the wire. High-quality copper is bright and soft in color, otherwise it is a defective product.

2. You can take a piece of wire and bend it repeatedly by hand. Any wire that feels soft, has good fatigue resistance, has high plastic or rubber feel and has no cracks in the wire insulation is a high-quality product.

3. Good quality wires are generally within the specified weight range. For example, the commonly used plastic insulated single-strand copper core wire with a cross-sectional area of ??1.5 mm2 weighs 1.8 to 1.9 kg per 100 m; the plastic insulated single-strand copper core wire with a cross-sectional area of ??2.5 mm2 weighs 3 to 3.1 kg per 100 m. kg; 4.0 mm2 plastic insulated single-strand copper core wire weighs 4.4 to 4.6 kg per 100 m, etc.

4. The copper core of qualified copper core wires should be purple-red, shiny, and soft to the touch. The copper core of fake and inferior copper core wires is purple-black, yellowish or white, with many impurities, poor mechanical strength, and poor toughness. It will break with a little force, and there are often disconnections in the wires.

5. Due to the low production cost of fake and inferior wires, vendors often sell them at low prices under the guise of low price and high quality, which deceives people.

Reference materials: Baidu Encyclopedia—Wire Specifications

Reference materials: Construction standard library—Wire and cable identification mark methods

Reference materials: Construction standard library—Electric power engineering Cable design standards