The minimum size copper equipment grounding conductor required on a motor branch circuit with a 30 amp circuit breaker and 12 awg copper counductors is

You can read the NEC online and find the answer. Hope this is a 240 circuit, otherwise itbis way over permitted amperage.

Hope this is a 240 circuit, otherwise itbis way over permitted amperage.
The voltage has nothing to do with the amperage/wire size relationship.
If's a motor branch circuit so #12 on a 30A is perfectly feasible.

The minimum size copper equipment grounding conductor required on a motor branch circuit with a 30 amp circuit breaker and 12 awg copper counductors isDo your own homework. It's all in the NEC and your study guides.

Why not tell us what you think it is and how you get it and we'll go over it?