Mạch nhánh & Đi dâyCâu 181 / 521
A 4" x 1-1/2" square box has a volume of 21.0 in³. With no clamps, devices, or other allowances, what is the maximum number of 14 AWG conductors permitted in the box?
a.10
b.9
c.11
d.8
Giải thích
Each 14 AWG conductor requires a 2.00 in³ volume allowance from Table 314.16(B). 21.0 ÷ 2.00 = 10.5, and you round down to 10 conductors. Rounding up to 11 would exceed the box volume, and 9 or 8 understates the count.
Trích dẫn luật: 2023 NEC §314.16(B)Luyện miễn phí toàn bộ 521 câu hỏi — không cần đăng ký.
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