Wiring Methods & Materials第 67 / 120 题
What is the minimum burial cover for a nonmetallic raceway listed for direct burial without concrete encasement, installed under a lawn?
a.18 inches
b.6 inches
c.24 inches
d.12 inches
解析
Listed nonmetallic raceways buried without concrete encasement require 18 inches of cover in locations not otherwise specified. Metal conduit needs only 6 inches, direct-buried cable needs 24 inches, and 12 inches applies to GFCI-protected 120-volt residential branch circuits.
法律依据: 2023 NEC Table 300.5免费刷完整 120 道题库 — 无需注册。
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