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Cable Size using Vc Value

*The following calculator is for reference only



This calculator assumes that cable types are single cores, insulated and sheathed, laid flat touching or touching in a wiring enclosure, and the calculator will determine the cable size for the maximum conductor temperature of 75℃. See the table below from AS 3008.1.1:2025

Calculate cable size
Single Phase Voltage drop allowed in % (Vd1∅):
  
? Select voltage drop allowed in percentage, e.g:5%
Length of the cable (L):

 
? Enter the length of the cable in meters

System voltage (V):
  
? Enter voltage supply in volts(V)

Current requirements (I):
  
? Enter current requirements in Amps

Three phase Vc: 0.00 mV/Am
Cable size: 0.00 mm2
Cable size using Vc
$$ V_{C3∅}=\frac{1000\times V_{d1∅}\%\times V}{L\times I\times1.155} $$
$$ V_{C1∅}=\frac{1000\times V_{d1∅}\%\times V}{L\times I} $$
Note: This equation accepts single-phase voltage drop values. The relationship between single-phase and three-phase is given as:

Vd3∅ = Vd1∅/1.155.

Where,
Vc3∅ = the three-phase voltage drop in mV/A.m given in the table below.
V = the system voltage, such as 230, or battery nominal voltages, e.g. 115.5 V
Vd1∅ = the single-phase voltage drop, can’t be over 5%.
L = the cable route length in meters.
I = the maximum circuit current in amps.
The maximum conductor temperature, 75℃

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