For a three-phase motor with a 30-A, 3-pole circuit breaker, what is the minimum size of the equipment grounding conductor required?

For a three-phase motor with a 30-A circuit breaker, the minimum size of the equipment grounding conductor is determined by the size of the overcurrent protection device, which in this case is 30 amps. According to the National Electrical Code (NEC), the grounding conductor must be sized based on the maximum overcurrent protection that it serves.

For a 30-A circuit, the minimum size required for the grounding conductor is typically based on the ampacity guidelines in the NEC. In this case, a 14 AWG conductor is the acceptable size for grounding when the circuit is protected by a 30-A circuit breaker. This is because the NEC provides specific tables which outline the minimum grounding conductor sizes based on the largest circuit conductor or the overcurrent protective device rating.

Understanding that 14 AWG is permissible here gives insight into the current carrying capacities and safety requirements, affirming that it can safely handle a fault current without causing excessive heating or failure.

In contrast, 12 AWG, 10 AWG, and 8 AWG conductors are larger than necessary based on the overcurrent protection specified. While these sizes could certainly provide a more robust grounding path, 14 AWG is the minimum required for the 30-A circuit and