For what type of motor is the minimum size equipment ground of 10 AWG copper considered?

The minimum size equipment ground of 10 AWG copper is specifically associated with three-phase motors due to their higher power requirements and operational characteristics compared to other types of motors. Three-phase motors typically operate at higher voltages and draw larger currents than single-phase, DC, or universal motors, which necessitates a more robust grounding system to ensure safe operation and protection against electrical faults.

A properly sized equipment ground is critical for handling fault currents and providing a low-resistance path back to the source, thus facilitating the operation of protective devices like circuit breakers. Since three-phase motors are prevalent in industrial and commercial settings, where greater power loads are common, using a 10 AWG copper ground enhances safety and compliance with electrical codes.