Voltage drop in the real world:
How different setups produce different results
YOU’RE PROBABLY FAMILIAR with voltage drop and how to calculate it. The standard formulas for single-phase and 3-phase systems are:
Single-phase: V drop = 2 K x Q x I x d ÷ CM 3-phase: V drop = 1.732 x K x Q x I x d ÷ CM where K is the resistivity of copper at 75˚C (167˚F), Q is an alternating current adjustment factor, I is the current in amps, d is the distance of the run of cable, and CM is the circular mil cross-sectional area of the conductors.