This is a ( not so good ) drawing of a transformer. Anything you connect will be eventually connected to the transformer. The primary side here is shown as being hooked to 2400 volts ... It could be much higher... or in some cases it could be lower.
The secondary side is where you connect your loads... in your example a motor.
There is a difference in potential between the two wires connected to the ends of the secondary winding of 240volts ...there is a difference of potential of 120 volts between either outside wire and the center tapped wire... usually the center tapped wire will also be grounded and is referred to as the neutral.
The difference in potential is caused by invisible waves (lines of flux) radiating from the primary winding because current flows through it. Because the current is alternating, it is continually rising and falling and reversing direction...the lines of flux cut across the windings of the secondary side ... the ratios of the windings determine the difference in the voltage from the primary side.
Any current flowing in a wire connected to any of the terminals on the transformer also has to be flowing in a wire connected to another terminal. Otherwise there won't BE any current flowing.
Appliances, heating elements,light fixtures, motors, or whatever loads you connect are engineered and constructed so that they can only "draw" a certain amount of current. In AC circuits their "impedance" ( resistance to A.C. current flow ) will only allow a certain amount of current to flow.
The apparent power is the amount of current flowing in the circuit multiplied by the voltage to which the load is connected.
In the scope of this discussion I think it would be acceptable to say that the watts of the circuit is the current multiplied by the voltage.
So the current is limited by design to a particular level, when connected to the voltage for which the load was designed.