What size EGC is required for a 2 hp motor supplied through a 2-pole breaker in a 120/208-V panel if the smallest conductors are used?

To determine the correct size equipment grounding conductor (EGC) for a 2 hp motor supplied through a 2-pole breaker in a 120/208-V panel, it is essential to consider the NEC (National Electrical Code) guidelines for grounding conductors.

For a motor rated at 2 horsepower, the full-load current can be calculated based on the voltage supply. Typical values indicate that a 2 hp motor at 208 volts may have a full-load current of around 9.2 amps. According to the NEC, when sizing the EGC, it is important to use the appropriate guidelines which specify that the EGC must be sized based on the rating of the overcurrent protection device (in this case, the 2-pole breaker) and the output current of the motor.

The NEC also provides tables, specifically Table 250.122, which detail the minimum size of EGC based on the size of the overcurrent device (the breaker). For a 15 or 20 amp breaker, a grounding conductor size of 12 AWG might suffice. However, as the size of the breaker increases, so does the requirement for a larger EGC to ensure safety and effective ground fault protection.

In scenarios where the smallest conduct