Cabinets and Wire-Bending Space (312), Underground Wiring (Table 300.7(A)), and the Article 300 General Rules

Two named sub-topics — "Cabinets and Panels" and "Underground Wiring" — plus the general rules of Article 300 that every other wiring-method question assumes. Article 300 was renumbered in 2026: 300.3 → 300.5 (conductors), 300.4 → 300.6 (protection), 300.5 → 300.7 (underground), 300.15 → 300.17 (boxes), 300.17 → 300.19 (fill), 300.19 → 300.21 (vertical supports). Article 312 was also renumbered: 312.5 → 312.8 (enclosures/cable entries), 312.6 → 312.9 (wire-bending space), 312.8 → 312.11 (splices in switch enclosures). Written from the 2026 text.

Two named sub-topics — "Cabinets and Panels" and "Underground Wiring" — plus the general rules of Article 300 that every other wiring-method question assumes. Article 300 was renumbered in 2026: 300.3 → 300.5 (conductors), 300.4 → 300.6 (protection), 300.5 → 300.7 (underground), 300.15 → 300.17 (boxes), 300.17 → 300.19 (fill), 300.19 → 300.21 (vertical supports). Article 312 was also renumbered: 312.5 → 312.8 (enclosures/cable entries), 312.6 → 312.9 (wire-bending space), 312.8 → 312.11 (splices in switch enclosures). Written from the 2026 text.

1. Underground wiring — 300.7 and Table 300.7(A)

Table 300.7(A) minimum cover, in inches (measured from the top of the conductor/raceway to the finished surface):

Location	Col. 1 Direct burial cables/conductors	Col. 2 RMC / IMC	Col. 3 Nonmetallic raceways listed for direct burial (PVC, RTRC)	Col. 4 Residential 120 V, ≤ 20 A, GFCI-protected branch circuits	Col. 5 ≤ 30 V irrigation / landscape lighting (UF, listed cable)
All locations not specified below	24	6	18	12	6
In trench below ≥ 2-in. concrete	18	6	12	6	6
Under a building	0 (in raceway, or MC/MI listed for direct burial)	0	0	0	0
Under ≥ 4-in. exterior concrete slab, no vehicles, slab extending ≥ 6 in. beyond	18	4	4	6 direct / 4 in raceway	6 direct / 4 in raceway
Under streets, highways, roads, alleys, driveways and parking lots	24	24	24	24	24
One- and two-family dwelling driveways and outdoor parking (dwelling use only)	18	18	18	12	18
Airport runways / adjacent taxiways	18	18	18	18	18

Notes that get tested: raceways approved for burial only where concrete-encased need a ; lesser depths are permitted where conductors rise for terminations or splices; Column 4/5 circuits may use the shallowest depth of any method in Columns 1–3; in solid rock, a metal raceway or a nonmetallic raceway listed for direct burial may be covered by extending to the rock; pool/spa/fountain lighting ≤ 30 V in

1. Underground wiring — 300.7 and Table 300.7(A)

This is where the public part ends.