Cable Sizing / Maximum Distance Calculator
Excessive voltage drop makes it difficult to push current through power cables. This can lead to an increase in energy consumption, overheating, and even the shortening of equipment life. Under voltage may also cause computers, printers, and sensitive electric equipment to shutdown.
The NEC Code Book recommends that the maximum combined voltage drop for both the feeder and branch circuit shouldn’t exceed 5%, and the maximum on the feeder or branch circuit shouldn’t exceed 3%. This calculator allows for the selection of a voltage drop of up to 3% on a circuit run. Minimum cable size can be calculated based on cable length, voltage, amperage, and acceptable loss. This cable sizing tool suggests THHN, which is appropriate for standard industrial applications. Wire selection must be in compliance with NEC Code Article 300.