POWER CABLE CSA FORMULA S= ∑ i x L ∆U x K Where, S =Cross Sectional area (mmsq) ∑i=Total Current (A) L=Loop Length (m) ∆U=Voltage Drop (volt) K=Constant, 57 for copper & 34 for Aluminum Consider that the average loop length(Twice the length between power source and Equipment) is around 25 meters, the CSA of the power cable should be S= 45x25 0.9x57 =21.92mmsq,where 0.9 is Voltage drop