Calculation Example

On a 480 volt branch circuit, the run from the last light pole to the next light pole is 200 feet. The twin-arm light pole supports two 400W EQ LED fixtures. The conductor is 8 gauge wire.
Using data from the tables provided in this section, we obtain the following information:
  • current in the run = 2 × 0.52 amps
    or
     1.04 amps
  • loop resistance of the conductor = 0.001308
Using the formula for calculating voltage drop, we find
(click in image to see full-size image)
and therefore
(click in image to see full-size image)