The RC4 performs identical to a toggle switch rated for 10AMPs. For a typical setup, on a vehicle, you would run a hot and ground to the Control Center. This powers the unit on. There is no power running to any of the screw in terminal blocks unless you bring power to them. Since they perform as a simple toggle switch. We recommend you run 10AMP fuses for each circuit. Say you wanna run your a pair of LEDs, those are rated to draw less than 10AMPs. All you will need is to run a 10amp fused hot through the NO (Far Left Pin) and then run your accessory hot into the COM (middle pin). Then run the ground on the accessory to any ground or back to the battery ground. In essance each RC Circuit is a 10AMP relay NC = 30, COM = 87, NC = 87A.