How To Calculate Cable Sizes |best| Now

[ V_d = \frac\sqrt3 \times L \times I_b \times (R \cos\phi + X \sin\phi)1000 \text (for 3-phase) ]

[ I_z \geq I_b ]

[ I_b \leq I_n \leq I_z ]

From IEC table – 2.5 mm² copper carries 24 A. Derating: ( C_t = 0.94 ) (35°C). ( I_z = 24 \times 0.94 = 22.56 A ) – adequate. how to calculate cable sizes