The ground wire in a two or three conductor #12 cable is a #14 bare ground wire.
Yes, in the form of GFCI circuit breakers, not as a receptacle.
No current bro? Depends
what kind of circuit? if it's a subfeed from one panel to another same size as hot wires. if it's a straight 240 volt circuit #8. depends on what kind of circuit.
4 AWG copper or 2 AWG aluminum.
The current will remain in a 220 volt circuit as long as the circuit load remains in the circuit and the circuit remains closed.
Yes, in the form of GFCI circuit breakers, not as a receptacle.
No current bro? Depends
# 3 gauge
yes <<>> No, the ground wire is never to be used as a neutral. In this case if you need a 120 volt circuit from the 220 volt circuit a three wire cable (3C #14) must be installed.
A volt can not be connected to a circuit.
Depends on the size of the circuit which you did not list.
Use 8 gauge wire.
A zero volt rail is a rail that is connected to 0V... What do you think it is? The 0V rail is often used as a common ground, although obviously it relies on your ground voltage being 0V.
The formula you are looking for is Watts = Amps x Volts. Amps = Watts/Volts. This comes to 4 amps load. Minimum size fuse would be 5 amps.
The formula you are looking for is 460 divided by the square root of 3 (1.73).
what kind of circuit? if it's a subfeed from one panel to another same size as hot wires. if it's a straight 240 volt circuit #8. depends on what kind of circuit.
4 AWG copper or 2 AWG aluminum.