Square number of wires and cables

The square number of wires and cables represents the cross-sectional area of wires, that is, the area of circular cross-section of wires, in square millimeters.

Calculation formula for cross sectional area of wires and cables

Calculation formula of cross sectional area of wires and cables; S=πr ²。 S stands for area; R represents radius; 2 represents square; π represents pi (3.1415926). The unit of cross-sectional area of wire and cable is mm. (mm) must be the square of the radius, not the square of the diameter.

Cross-sectional area of wires and cables

The ampacity per unit cross-sectional area of cables and wires is related to many factors, including the material of cables and wires, the number of cables and wires, and the way of laying and erecting.    In the case of the same material, laying and erection method and the same number of conductors, the smaller the cross-sectional area, the greater the ampacity per unit cross-sectional area, because the skin effect needs to be considered.    With the same material and the same number of conductors, the current carrying capacity of buried cables and wires is higher than that of pipes in the air, because the heat dissipation of buried cables and wires is better.