How to select and determine the wire diameter of EV high-voltage cables?

The diameter of high-voltage cables on the market ranges from 1.5mm2 to 120mm2, and the quality of products produced by various manufacturers is also different. So how to choose a high-voltage cable with a suitable diameter according to the actual situation?

1. High-voltage cables need to meet LV216-1/2, ISO19642 and other standards.

2. Determine the load characteristics of the electrical components connected to the high-voltage wiring harness, including steady-state current size, voltage requirements, transient conditions, current intensity and current waveform (smooth, pulse, frequency, etc.).

3. Then determine the cross-sectional area of ​​the wire according to the steady-state current.

Calculation formula of current intensity and cross-sectional area:

The current intensity is: I=P/U (*P is the load power, *U is the rated voltage)

The calculation formula of the cross-sectional area of ​​the wire is: A=IρL/UVL (A is the cross-section of the wire, I is the current value, ρ is the resistivity of the copper wire, L is the length of the wire, and UVL represents the allowable voltage drop of the wire)

The current density S=I/A (I is the current intensity, A is the cross-section of the wire), and the wire is prevented from overheating by checking the current density.

Refer to the table for the matching of copper core wire diameter and current carrying capacity. It can be seen that when the maximum current is 40A, at 125°C, use OMG 6mm² high-voltage wire; when the maximum current is 150A, at 125°C, use OMG 35mm² high-voltage cable; under 180℃, use 50mm² harness; under 250℃, select OMG 70mm² high-voltage cable.

For more ev high-voltage cable and ev charging cables,please visit the official website of OMG: https://www.omgevcable.com