Some people don't recommend doing this but I have in the past as a temporary short term setup.If you are going to use 2 poles for a 230 source , it should not matter because any phase will trip if the current rating is exceeded. That would be called a double pole application. If you are going to use just one pole for 120 volts, verify that the voltage to neutral is 120 volts. Here in the US one of the poles to neutral can be approximately 200 volts (called the "High Leg") and the other two poles ("Legs") will normally be 120 volts to neutral.