A properly sized cable is not just an economic choice—it is a life safety decision.
While not directly in DIN VDE 0298 Part 4, harmonics cause additional heating in the neutral conductor. The standard assumes sinusoidal currents. For non-linear loads, additional derating (per VDE 0100-520 or HD 60364-5-52) applies. din vde 0298 part 4
I_z = 9.75 A.