What is the maximum allowable voltage drop for a motor located 160 feet from the panelboard?

The maximum allowable voltage drop for a motor located a significant distance from the panelboard is generally recommended to be 3%. This guideline helps to ensure that the motor receives adequate voltage under operating conditions. A voltage drop exceeding this threshold can lead to inefficient operation, overheating, and potential damage to the motor and other connected equipment.

The National Electrical Code (NEC) also suggests that for branch circuits supplying motors, a maximum voltage drop of 3% for single-phase circuits and 5% for three-phase circuits is often acceptable. Given that a 160-foot distance is considerable, maintaining the voltage drop within this limit is crucial for performance and reliability.

Choosing a lower percentage for voltage drop can be more efficient, but it may not always be practical, especially in longer runs. Therefore, the 3% threshold strikes a balance between efficiency and practical installation considerations, making it an appropriate standard for motors in this scenario.