I'm an electrician living in Canada. Pay attention to that.
120V5V0V. These are the same voltage. Single phase. Used in a
220V-240V are the same. Single phase also. Used only for bake oven and
208V is the voltage of a 3 phase circuit. I suggest you go outside and
check out the wire(s) that connect your house.
If the wire has 3 wires, 2 black cover wires and an uncovered aluminum
ground wired, it is the single phase one 120/240. Every house has this
If the wire has 4 wires, 3 black cover wires and an uncovered aluminum
ground wired, it is the 3 phase voltage 208V.
You can have both of them connected to your house. It is rare but it
can happen. Pay attention to that.
Also, you can't replace 208V by 220V. It's not the same thing at all.
I suggest you call someone who knows well electricity (an electrician)
before attempting to do something with it, if you don't want to burn
any electric things.