LLC Landscape Lighting Safety & Code Compliance 3 — Questions and Answers
Question 1: An installer finds existing landscape wiring spliced inside a weathertight junction box buried underground without conduit fill. What NEC violation exists?
- Splices are not permitted underground
- The junction box must be accessible (Correct answer)
- Underground boxes must be metal
- Weathertight boxes cannot contain splices
Correct answer: The junction box must be accessible
NEC Section 300.15 requires that all junction boxes remain accessible; a buried box without an accessible cover violates this rule.
Question 2: What is the required minimum clearance between a low-voltage landscape light fixture and the edge of a pool water surface?
- 5 feet
- 7.5 feet (Correct answer)
- 10 feet
- No clearance required for fixtures under 15V
Correct answer: 7.5 feet
NEC Article 680.22 prohibits luminaires within 7.5 feet horizontally from the pool edge unless they meet specific criteria.
Question 3: When landscape lighting conductors are run in PVC conduit underground, the minimum burial depth under a public sidewalk is:
- 6 inches
- 12 inches (Correct answer)
- 18 inches
- 24 inches
Correct answer: 12 inches
NEC Table 300.5 requires PVC conduit under sidewalks to be buried at least 12 inches deep.
Question 4: A landscaper installs a 120V in-ground well light. Where must the GFCI protection be located?
- At the main panel only
- At the first outlet in the circuit
- At or before the point of use (Correct answer)
- At the transformer secondary
Correct answer: At or before the point of use
GFCI protection for 120V outdoor fixtures must be provided at or before the point of use per NEC 210.8(A)(4).
Question 5: Type UF cable used for direct burial in landscape lighting must be protected from physical damage when it emerges from the ground. What is the required protection height above grade?
- 6 inches
- 8 inches
- None — UF is self-protected
- 18 inches to the point of termination (Correct answer)
Correct answer: 18 inches to the point of termination
Where UF cable emerges from the ground, it must be protected by conduit or equivalent from the point of emergence to the connection point above grade, typically measured to the equipment.
Question 6: Which of the following best describes a 'wet location' as defined by the NEC for outdoor landscape lighting purposes?
- Any area exposed to direct sunlight
- Locations exposed to weather and saturating moisture (Correct answer)
- Any underground installation
- Any location within 10 feet of an irrigation head
Correct answer: Locations exposed to weather and saturating moisture
The NEC defines wet locations as installations exposed to weather including rain, sleet, and similar conditions that result in saturation.
Question 7: A landscape lighting system uses a multi-tap transformer with outputs of 12V, 13V, and 14V. Why would an installer use the 14V tap?
- To reduce transformer heat output
- To compensate for voltage drop on long wire runs (Correct answer)
- To increase wattage capacity of the transformer
- To meet NEC voltage drop requirements of under 3%
Correct answer: To compensate for voltage drop on long wire runs
Higher voltage taps compensate for voltage drop over long conductor runs, ensuring fixtures at the end of runs receive adequate voltage.
LLC Landscape Lighting Safety & Code Compliance 3
An installer finds existing landscape wiring spliced inside a weathertight junction box buried underground without conduit fill.
What NEC violation exists?