To achieve a maximum voltage drop of 2% on a circuit with a load of 32 amperes over 400 feet, what is the correct copper conductor size?

To determine the appropriate conductor size needed to maintain a maximum voltage drop of 2% in a circuit carrying a load of 32 amperes over a length of 400 feet, considerations around the resistivity of the copper conductor and the allowable voltage drop are vital.

The voltage drop in a conductor is influenced chiefly by its length, current load, and the cross-sectional area (size) of the wire. The formula for calculating voltage drop takes these factors into account and shows that a larger conductor size will yield less resistance, thereby reducing the overall voltage drop.

Given that the load is 32 amperes and the circuit length is 400 feet, the calculation reveals that a larger conductor size is necessary to limit the voltage drop to 2%. In practical applications, the American Wire Gauge (AWG) system demonstrates that as the gauge number decreases, the conductor's diameter and consequently its current-carrying capacity increases.

Selecting 1 AWG as the correct size ensures that the resistance is low enough to maintain the voltage drop within the required limits for such a load and distance, making it an appropriate choice for ensuring efficient operation of the circuit without significant energy loss. This choice effectively supports the electrical system's performance, maintaining both safety and efficiency.