Wire sizing is the only difference in ....230 draws 1/2 the amps. Most people don't fool with 115 but either will work just fine. One other note that I just recently discovered....you can run a Grundfos 3" 1/2 hp 115 volt on a little Honda EU2000 inverter generator....you cannot run a normal 115 volt 1/2 motor on a small generator. I have a Vector 1000 watt running 2000 watt surge 12 volt inverter on the service truck for running small hand tools, and I can actually run the grundfos on that.....I was amazed.