Wiring Methods & Materials第 63 / 120 题
A short raceway nipple no longer than 24 inches connects two enclosures. What fill percentage is permitted?
a.31 percent
b.40 percent
c.53 percent
d.60 percent
解析
Notes to Chapter 9, Table 1 permit a nipple not exceeding 24 inches in length to be filled to 60 percent of its total cross-sectional area, because heat buildup and pulling friction are both minimal over such a short run. The 40, 53 and 31 percent values are the normal fills for three or more, one, and two conductors respectively.
法律依据: 2023 NEC Chapter 9, Table 1, Note 4免费刷完整 120 道题库 — 无需注册。
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