Mạch nhánh & Đi dâyCâu 200 / 521
Six current-carrying 12 AWG THHN conductors (90°C, 30 A base) share a raceway. Applying only the adjustment factor for 4–6 conductors, what is the adjusted ampacity?
a.30 A
b.21 A
c.27 A
d.24 A
Giải thích
The adjustment factor for 4–6 current-carrying conductors is 80%. 30 A × 0.80 = 24 A. 70% (21 A) applies to 7–9 conductors, and 30 A ignores the required adjustment.
Trích dẫn luật: 2023 NEC §310.15(C)(1)Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- The internal cross-sectional area of 1/2" EMT is 0.304 in³ per Table 4. For three or more conductors, what usable fill area (40%) is available?
- The internal area of 3/4" EMT is 0.533 in² per Table 4. What is the 40% usable fill area for three or more conductors?
- Given a 40% usable fill area of 0.213 in² (3/4" EMT) and a 12 AWG THHN cross-sectional area of 0.0133 in² (Table 5), how many 12 AWG THHN conductors fit?
- Per Table 310.15(C)(1), what adjustment (derating) factor applies when there are 7 to 9 current-carrying conductors in a raceway?
- Per Table 310.15(C)(1), what adjustment factor applies when there are 4 to 6 current-carrying conductors in a raceway?
- Per Table 310.15(C)(1), what adjustment factor applies when there are 10 to 20 current-carrying conductors in a raceway?
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