Question 13048 of 749 · Maryland Journeyperson Electrician Exam
Nine current-carrying 12 AWG THHN copper conductors are installed in one conduit at 30 °C ambient. What is the adjusted ampacity of each conductor based on the 90 °C column?
Exactly one answer is correct.
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Correct answer to question 13048
- D: 21 A
Explanation
12 AWG copper has a 90 °C ampacity of 30 A, and 7 to 9 current-carrying conductors take a 70 % adjustment: 30 x 0.70 = 21 A. 24 A uses the 80 % factor for 4 to 6 conductors.
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