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Practice question · NEC Table 300.5
How Deep Do You Bury UF Cable?
Exam-style question (Sparky QOTD)
Per Table 300.5, what is the minimum cover for a direct-buried UF cable on a 120V residential branch circuit?
A. 18 in.
B. 24 in.
C. 6 in.
D. 12 in.
Answer: B) 24 in.
Where to Find It
Open your Code book to Table 300.5. Find the column labeled “Direct Burial Cables or Conductors” — the value is 24 inches. That's the whole lookup; the exam hands you the table and watches whether you read the right column.
Why 24 Inches
Direct-buried cable has no raceway around it — nothing between the shovel and the conductors. So the Code demands the deepest cover in the table. Memorize the three columns as a set: direct burial 24 / nonmetallic raceway 18 / RMC 6. If you know all three, no Table 300.5 question can touch you.
The Trap
Choice D (12 in.) is real — it's the column for residential 120V branch circuits with GFCI protection. But this question never mentions GFCI, so you stay in the general direct-burial column: 24 inches. On test day, the word “GFCI” in the stem is the signal that moves you to a different column. No GFCI, no shortcut.
Exam Tip
Table 300.5 questions are pure column-reading. Cover the answer choices, find your column first, then uncover. The wrong answers are always the other columns' values — the test writers barely have to try.
Keep Drilling
This is one of 33 NEC topics. Sparky's 1,087 codebook-first questions drill all of them — every question a lookup rep with your book open, 15 minutes a day.