do you mean a 7.5 amp 240 volt....there is no such thing as a 7.5 signal phase motor that i have ever heard of...but this may help if you can't locate the plate on the side of the motor for the wiring diagram, look on the inside of the (junction box)
On a three wire supply system if you connect the two 110V wires together and they are across the phase they will short out and trip the breaker. If the two 110V wires are supplied from across the phase and connected to a motor then the motor will run. If the 110V wires are on the same phase nothing will happen.
Sounds like both phase wires are connected to the same phase.
f your supply is a Y connected transformer (4 wires COM) with a phase to phase voltage of 380 volts (voltage between any two of the hot wires) , utilizing a true Y connection to your load (connections of one hot lead and neutral for each phase to your load will give a voltage of 380 รท sqrt 3 = 380 รท 1.732 = 220 volts.
reverse wires
A light bulb connected between to wires, each having 300 volts to ground that are in phase, will not light, because there is no differential voltage available to do any work. If each wire has 300 volts to ground and are out of phase (600 volts between them) the light bulb will be lit, if it is rated at least for 600 volts, otherwise it will burn out.
A single phase meter will have two "hot" wires, one black the other red. Each wire will carry 120 volts. Essentially these two wires together will provide you with 240 volts. Hire a professional when dealing with electricity.
There is only one ground wire needed on any motor, single or three phase.
There should be 2 or 3 wires. A hot, a neutral and sometimes a ground.
It depends on how, and with what you change them.
It would help to know the voltage of the motor. See related links below for motor connections.
Switch two of the three wires.
Nothing, the equipment will still run the same.Because this is a AC voltage