Unless you have an industrial connection to the power grid, your connection maxes out at 16 amps anyways and most mains switches allow these 16 A.
That said, 12 V * 30 A / 0.8 (PSU efficiency) = 450 watts. 450 W / 220 V = 2.05 A.
That said, 12 V * 30 A / 0.8 (PSU efficiency) = 450 watts. 450 W / 220 V = 2.05 A.