Nerd point:
Window and windshield heating on the A320/321 are powered by AC bus 1 (left) and AC bus 2 (right): that is 115 Volts AC.
However, if all three AC phases are used for window heating (and they normally are for large energy users such as heating and electric motors), then there will always be 172.5 Volts AC between any two phases.
Window heating is never powered by inverters - If AC bus 1 or 2 are lost, then so is the window heat on that side.