Q&A(FAQ) How to Select Wiring Cables?
1. Why Proper Wiring Matters
Care must be taken when selecting cables for wiring the input and output lines of a power supply.
Although electrical cables have only small resistance, this resistance can still cause voltage drops and generate heat as current flows through them.
For these reasons, the power supply should be wired using short, thick cables.
2. The required cable thickness depends on the current level (reference values)
| No. | AWG No. | Cross-sectional Area [mm2] |
Line voltage drop per 1A [mV/m] |
Max current (Ta=40℃) UL1015 (600V 105℃) [A] |
|---|---|---|---|---|
| 1 | 30 | 0.051 | 358 | - |
| 2 | 28 | 0.081 | 222 | - |
| 3 | 26 | 0.129 | 140 | 5.8 |
| 4 | 24 | 0.205 | 88.9 | 7.6 |
| 5 | 22 | 0.326 | 57.5 | 10.0 |
| 6 | 20 | 0.517 | 37.6 | 13.1 |
| 7 | 18 | 0.823 | 22.8 | 17.2 |
| 8 | 16 | 1.309 | 14.9 | 22.8 |
| 9 | 14 | 2.081 | 9.5 | 30.4 |
| 10 | 12 | 3.309 | 6.0 | 40.6 |
| 11 | 10 | 5.262 | 3.8 | 55.3 |
*According to the data provided by cable supplier
3. Notes
- i.Bundling cables reduces heat dissipation.
When bundling 5 or more cables, please apply an 80% derating of the rated current. - ii.Cables have inductance in addition to resistance.
Therefore, the power supply should be wired using short and thick cables. - iii.The voltage drop across the remote sensing cables should be 0.3 V or less (when using the remote sensing function).