When using a 12 AWG wire and 60 amp fuses in a motor branch circuit, what is the largest equipment grounding conductor required by NEC®?

The largest equipment grounding conductor required when using a 12 AWG wire and 60 amp fuses in a motor branch circuit is determined based on the National Electrical Code (NEC) guidelines which specify the appropriate sizing of grounding conductors for given circuit configurations.

According to the NEC, the size of the equipment grounding conductor is generally based on the rating of the overcurrent protection device, which in this scenario is a 60 amp fuse. For a circuit protected by 60 amps, the NEC provides tables that outline the necessary grounding conductor size.

For a 60 amp circuit with branch conductors sized at 12 AWG, the NEC typically would allow for a 12 AWG grounding conductor as well. This is compliant with the NEC requirements which ensure proper safety measures are in place for grounding conductors in relation to the ratings of the circuit conductors.

Choosing a larger size such as 10 or 8 AWG may not be necessary under these circumstances unless there are specific additional conditions or for unique applications, which often will not be the case in standard residential or commercial wiring practices.

The answer of 12 AWG adheres to the NEC standards for size and is therefore the appropriate choice for this question.