The total power is 3 kW, and the rated voltage is 220 V for any calculation of the current

The total power is 3 kW, and the rated voltage is 220 V for any calculation of the current

P = 3000W, u = 220V
（1） If the appliance is connected to 220 V voltage:
I=P/U=3000/220=150/11≈13.64A
（2） If the voltage of the appliance is not 220 V, the resistance of the appliance should be calculated first
R=U^2/P=220^2/3000=242/15≈16.13Ω
Then divide the actual voltage by the resistance:
I=U/R≈U/16.13

Recently, I came across a physical problem: how many square meters of wire do I need to use when the voltage is 220V 3KW? How to calculate this

First calculate the current 3000 / 220 = 13.6a, the safe current carrying capacity of copper conductor is 5 ~ 8A / mm2, and the safe current carrying capacity of aluminum conductor is 3 ~ 5A / mm2, so the copper conductor is 13.6 / 5 = 2.72, the aluminum conductor is 13.6 / 3 = 4.53, and the aluminum conductor is 5mm2 or thicker