Which Table 300.5 row should be used for underground conduit under a building?

Which Table 300.5 row should be used for underground conduit under a building?

• A. All locations not specified below
• B. Under a building
• C. Under streets, highways, roads, alleys, driveways, and parking lots
• D. In or under airport runways, including adjacent areas where trespassing prohibited

Answer: (B)

Location determines the minimum cover for underground conduit. If the conduit runs beneath a building, you use the row for “under a building” because the building’s presence changes exposure and protection compared with open ground, streets, or runways. That category accounts for the fact the conduit is beneath the structure (often under a slab or subfloor) and typically requires a different, usually smaller, minimum depth than more exposed locations. Other rows apply to more exposed situations—under streets, or under airport runways—where there’s a higher risk of damage and different loading, so they require different minimum depths. The catch-all row is only for installations that don’t fit any specific category, which isn’t the case here. Therefore, the under a building row is the appropriate choice.

Location determines the minimum cover for underground conduit. If the conduit runs beneath a building, you use the row for “under a building” because the building’s presence changes exposure and protection compared with open ground, streets, or runways. That category accounts for the fact the conduit is beneath the structure (often under a slab or subfloor) and typically requires a different, usually smaller, minimum depth than more exposed locations. Other rows apply to more exposed situations—under streets, or under airport runways—where there’s a higher risk of damage and different loading, so they require different minimum depths. The catch-all row is only for installations that don’t fit any specific category, which isn’t the case here. Therefore, the under a building row is the appropriate choice.