19.53 V > 6.9 V → → increase cable size.
[ V_d = \frac\sqrt3 \times L \times I \times (R\cos\phi + X\sin\phi)1000 ] how calculate cable size
Select a cable where the .
[ V_d = 7.3 \times 21.7 \times 50 / 1000 = 7.92 \text V ] Still slightly over 6.9 V → try 10 mm² (~4.4 mV/A/m): [ V_d = 4.4 \times 21.7 \times 50 / 1000 = 4.77 \text V \ \text(OK) ] Step 4 – Consider Short-Circuit Temperature Rise For critical installations, ensure the cable can withstand a short circuit until protection operates: 19.53 V >
[ I = \fracPV ]