For a feeder supplying multiple motors, what is the minimum size aluminum THWN/THHN conductors permitted?

When determining the minimum size of aluminum THWN/THHN conductors for a feeder supplying multiple motors, it's essential to consider the National Electrical Code (NEC) requirements and the specific applications of these conductors. The code outlines various parameters for conductor sizing, including ampacity and the types of loads being served.

Aluminum conductors have different ampacity compared to copper conductors, which means the sizing will differ based on the material used. According to NEC guidelines, for feeder applications, 6 AWG aluminum conductors are often identified as the minimum size permissible due to their ability to safely handle the electrical load associated with feeding multiple motors.

This sizing ensures that the conductors can adequately manage the current demand without exceeding temperature limits, which is particularly crucial in a scenario with multiple motors that could have varying starting currents and continuous loads. Using the appropriate size helps prevent overheating, reduces the risk of voltage drop, and adheres to safety regulations.

In summary, using 6 AWG aluminum THWN/THHN conductors is a standard practice to ensure adequate performance and safety for feeders supplying multiple motors, making it the correct choice for this scenario.