For those off-grid folks who have a 240V water heater but one inverter with 120V single pole power here is a solution. You can hook the red and white wires to the neutral bus, the green to the ground, and the black wire to your line circuit 15A circuit breaker. Because Ohm’s law works consistently, the water heater will function at roughly 1200W. It will take four times as long to heat the water, but a large tank will allow reasonable daily use. If you wish to test the concept and have a multimeter, unhook the water heater, turn the thermostats all the way up and test the resistance red wire to black wire, then connect red to white and test resistance from black to the connected red and white. It should read roughly 12.6 ohms either way. 1200W/120V=10A #homesteading #offgrid #waterheater