What is the voltage drop on a single-phase, 208-volt branch circuit supplying a 130-ampere load at a distance of 185 feet with 2/0 AWG THWN aluminum conductors?

To determine the voltage drop in this scenario, you can use the voltage drop formula specific to single-phase circuits:

Voltage Drop (V) = (2 × K × I × L) / 1000

Where:

• K is the resistivity constant for the material (copper or aluminum). For aluminum conductors, K is approximately 12.9 ohms per mil foot.

• I is the current in amperes (130 A).

• L is the one-way distance in feet (185 ft).

First, substitute the values into the formula. Since this is a single-phase circuit, the formula includes a factor of 2 to account for both the outgoing and return paths of the current:

Voltage Drop = (2 × 12.9 × 130 × 185) / 1000

Calculating this gives:

• 2 × 12.9 = 25.8

• 25.8 × 130 = 3354

• 3354 × 185 = 620490

Then, divide by 1000:

620490 / 1000 = 620.49

To convert this to volts of drop, calculate the voltage drop by putting it into context of the initial voltage. Finally