In the choice of power cord, in fact, as long as you remember a few very simple formulas, these problems will be solved. When selecting the power cord, you must know the power consumption of the equipment. Under this known condition, the current is calculated by using the formula of three-phase AC electric power, and the formula is:

P (electric power) = √ 3× 380 (three-phase voltage )× I (current )× cosφ, where COS φ is the reactive loss of inductive load, and a conservative constant of 0.85 is enough:

√ 3 = 1.732 This is the basic mathematical knowledge, and the current (i) is deduced:

I = p (power) /√3×380×0.85(cosφ). Use current to find out the diameter of the power line (note that this is the line diameter, not the cross-sectional area, and the specifications of the power line are all expressed by the cross-sectional area). Line diameter formula:

D = 0.8 ×√ I, and then calculate the cross-sectional area of the conductor with the diameter of the conductor. This is a mathematical formula: radius × radius × 3.14; All right, that's it. The specifications of the power cord used have been worked out.

Very simple, you need to remember two formulas, one:

P (electric power) = √ 3× 380 (three-phase voltage )× I (current )× cos φ.

Another formula: d = 0.8 ×√ i.