Sys, this is a fundamental part of electricity. If you have a 240-volt load, and the current is 14 amps in each hot, that's a total of 14 amps, and there will be no neutral current (and likely no neutral at all).
The same amount of electrical power (watts) supplied at 120 volts would require 28 amps. Since volts x amps = watts (by definition), if you halve one, the other doubles, and power remains the same.
Lower current (and the resulting reduced need for conductor current capacity) and less voltage drop are why higher voltages are used for larger loads. After all, insulation is cheaper than conductor.
