The capacitor corrects the power factor issue that the inductor would make if you have motors or transformers. By connecting the capacitor it reduces how much current you draw. You need the correct capacitance too much or too little capacitance doesn't reduce the current enough. Having no capacitors the current peaks above 2 mA. Having all three capacitors the current peaks above 4 mA. Having just the middle 7uf cap current only peaks at 70 uA
