According to NEC guidelines, what is the maximum permissible voltage drop for feeders?

The maximum permissible voltage drop for feeders, as outlined in the National Electrical Code (NEC) guidelines, is 5 percent. A voltage drop of up to 5 percent is considered acceptable during normal operation to ensure that the electrical devices and appliances connected to the feeder receive sufficient voltage to operate effectively. Keeping the voltage drop within this limit helps maintain performance, efficiency, and safety.

This standard is particularly important for feeders because they distribute power throughout a building or a large installation. Excessive voltage drop can lead to issues such as overheating, underperformance of connected devices, and potential safety hazards. For branch circuits, a lower voltage drop is often recommended to ensure even more reliable performance for the devices that draw current from these circuits, typically capped at around 3 percent.

The understanding of permissible voltage drop is crucial for anyone involved in electrical installations to ensure compliance with NEC regulations and to promote the longevity and proper function of electrical systems.