Dịch vụ & Phân phốiCâu 22 / 521
A feeder supplies a continuous load of 176 A. What minimum conductor ampacity (before derating) is required?
a.220 A
b.176 A
c.200 A
d.141 A
Giải thích
Per 215.2(A)(1)/210.19, feeder conductors must be sized at 125% of the continuous load: 176 A x 1.25 = 220 A. Using 176 A ignores the 125% factor, and the other values misapply it.
Trích dẫn luật: 2023 NEC §215.2Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
Câu hỏi liên quan cùng chủ đề
- Six current-carrying conductors are installed in a single raceway. What adjustment factor applies to their ampacity?
- How many current-carrying conductors can be in a raceway before an adjustment (fill derating) factor must be applied?
- For equipment terminals on a circuit rated 100 A or less (not marked otherwise), which temperature column must be used to size conductors?
- Six 3 AWG THHN copper conductors (90 C ampacity 110 A) are in one raceway at 30 C ambient. After the fill adjustment, what is the derated ampacity?
- Using the 60 C column of Table 310.16, what is the ampacity of a 6 AWG copper conductor?
- What is the maximum overcurrent protection allowed for a 12 AWG copper conductor under the small-conductor rule?
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