115v?
Common voltage in the USA.
Weight was a large factor as well.
If you ever have seen one of these motor-driven inverters, you would soon realise how heavy they were.
Three-phase and 115v helped with all this as well...made the units a practical weight.
Yes, but why stop at 115V?
Think of the mathematics.
Double the voltage at a given power. You can halve your current.
Double the voltage and half the current means that for given acceptable resistivity losses, you can increase your resistance four times. Which means one-quarter the cross-section and weight of wires!
You do have to use thicker insulation, though. At some voltage, more insulator needed will compensate for saved conductor.
Now, in aircraft, you have high frequency. Which means high currents are a big problem - induction losses and leaks go up with the magnetic field!
You should like to have higher voltage on aircraft than on ground - exactly to save weight.
What are the AC voltages on a Comet or a Britannia or Caravelle? What about Tu-114 or Il-62?