Rising Edge Services, LLC

Easy Voltage Drop

Three Phase Voltage Drop, "VD" = (1.732 x K x I x L) / CM

Single Phase Voltage Drop, "VD" = (2 x K x I x L) / CM

Percent Voltage Drop, "%VD" = (VD / E) x 100

K = 12.9 for Copper, and K = 21.2 for Aluminum, when using Feet

OR

K = 42.3 for Copper, and K = 69.5 for Aluminum, when using Meters

Voltage Drop Calculations:


Amperage, "I"
Length in Feet, "L"
Choose Wire Size

Percent Voltage Drop Calculations:

Voltage, "E"

Note: The constants are based on the ohms/km and ohms/kFT for 1000 kcmil wire in NEC Chapter 9, Table 8.