My knowledge goes as far as connecting an LED or small DC motor to a battery
You know, given what you say above, maybe building a circuit to control and activate a switch that moves 20KW (!!twenty-two-thousand-watts!!Yikes!!) around is maybe not the best choice for a first project. You're talking modifying a switch to control lethal voltages and currents... I wouldn't touch that stuff myself. Not to mention the fact that your house insurance wouldn't touch it either 