Mạch nhánh & Đi dâyCâu 231 / 521
A 240 V single-phase circuit uses 10 AWG copper (10,380 cmil) carrying 24 A over a one-way length of 150 ft, with K = 12.9. What is the approximate voltage drop and percentage?
a.4.5 V, about 1.9%
b.17.9 V, about 7.5%
c.8.9 V, about 3.7%
d.2.2 V, about 0.9%
Giải thích
VD = 2 × 12.9 × 24 × 150 ÷ 10,380 = 92,880 ÷ 10,380 ≈ 8.9 V, which is 8.9/240 ≈ 3.7%. The other options misplace the length, current, or divide by the wrong circular-mil value.
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Câu hỏi liên quan cùng chủ đề
- For the combined feeder plus branch circuit, the NEC informational note recommends total voltage drop not exceed what percentage?
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