Question 13037 of 731 · Texas Journeyman Electrician Exam
A three-phase 480 volt load of 100 A is 300 feet away. Ignoring ampacity, what is the smallest aluminum conductor that holds voltage drop to 3 %?
Exactly one answer is correct.
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Correct answer to question 13037
- A: 1 AWG
Explanation
Allowed drop is 0.03 x 480 = 14.4 V, so CM = 1.732 x 21.2 x 100 x 300 / 14.4 = 76,499 circular mils, which requires 1 AWG (83,690). Using the copper K of 12.9 would wrongly point to 3 AWG.
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