Is there a way to measure AC power/current delivered through 2 or 3 wire cable? I know that from Ampère's Law the total current of both wires is zero, but is there a way to measure power in cable in other methods?
My intention is to measure average power from typical home devices like washing machine, oven etc,but without entering the circuit. I know the RMS voltage of my net (220V) so I need to know the current. I know that there are pen testers which may figure out whether a current is flowing through a certain cable but it's not telling how much current flows.