Question 4103 of 731 · Texas Journeyman Electrician Exam
A 12 AWG copper THHN conductor has a 90 C ampacity of 30 amperes in Table 310.16. What is the maximum overcurrent protection generally permitted for it?
Exactly one answer is correct.
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Correct answer to question 4103
- B: 20 amperes
Explanation
240.4(D) limits the overcurrent protection for 12 AWG copper to 20 amperes unless specifically permitted elsewhere, such as for motors. The higher table value may still be used as the starting point for adjustment and correction.
More questions: Branch Circuits, GFCI and AFCI
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- 4106An 8 AWG copper THHN conductor connects to terminals rated 75 C on both ends. What ampacity may be used for the circuit?
- 4107For a circuit rated over 100 amperes with conductors larger than 1 AWG, which temperature column may be used for termination purposes unless equipment is marked otherwise?
- 4108When 90 C rated THHN conductors are installed with 75 C terminations, what is the 90 C ampacity used for?
- 4109How may a 10 AWG grounded conductor be identified?