Doing a little basic Ohm's Law here (ignoring the fact that this is AC not DC) you'll find that a 5000 watt (I just used this value for comparison) 208v unit draws 24 amps and has ~8.67 Ohms resistance. The same unit at 240v would draw ~28 amps and put out 6720 watts (R basically stays the same). Their life span will be real short.
