Download Sizing Guide
Voltage Drop for 4B&S Cable:
To calculate the voltage drop of 4 B&S copper cable, use the following formula:
Voltage Drop = Length x Current x 0.017
Length = Total length of cable in metres.
Current = Current draw (amps) through the cable.
Area = Cross sectional area of the copper (in this case 20.26mm²)
Formula only applies to copper at 25°C, voltage drop increases with both ambient and cable temperature, at approx 0.4% per °C.
0.017 - This multiplication factor only applies to copper
Example for 4 B&S:
How much voltage drop over 10m of 4 B&S with a current draw of 135A?
- 10m x 135A x 0.017 = 22.95
Divide this by 20.26 (cross sectional area of 4 B&S - mm²)
You will have a drop of approximatley 1.13 Volts over the 10m length