Besides the power wires you would also need to consider heat transfer and the durability of the heating elements. Transfering that much energy into water within 5 seconds likely isn't even possible as the heating elements would need to be so hot it would flash boil the water immediately next to them, forming a protective layer of vapor, killing your heat transfer and probably melting the heating elements.
Half-timeHero t1_j0f2qvs wrote
Reply to comment by Stopa42 in 5 second toaster and kettle by F1NNTORIO
Additional potential problems:
Besides the power wires you would also need to consider heat transfer and the durability of the heating elements. Transfering that much energy into water within 5 seconds likely isn't even possible as the heating elements would need to be so hot it would flash boil the water immediately next to them, forming a protective layer of vapor, killing your heat transfer and probably melting the heating elements.