Question 13049 of 731 · Texas Journeyman Electrician Exam
Eight current-carrying 12 AWG THHN copper conductors run through an area with a 45 °C ambient. What is the allowable ampacity using the 90 °C column?
Exactly one answer is correct.
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Correct answer to question 13049
- A: 18.3 A
Explanation
Start with 30 A (90 °C column), apply the 41 to 45 °C correction of 0.87 and the 70 % adjustment for 7 to 9 conductors: 30 x 0.87 x 0.70 = 18.3 A. Applying only one of the two factors gives 21.0 A or 26.1 A.
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