LLC Installation Techniques 2 — Questions and Answers
Question 1: When installing low-voltage landscape lighting cable, what is the minimum burial depth recommended by NEC for direct-burial cable in a typical residential landscape bed?
- 6 inches (Correct answer)
- 12 inches
- 18 inches
- 24 inches
Correct answer: 6 inches
NEC requires low-voltage (under 30V) landscape lighting cable to be buried at least 6 inches deep in typical landscape applications.
Question 2: Which wire connection method is most recommended for outdoor low-voltage landscape lighting splice connections to prevent corrosion?
- Twist-on wire nuts
- Waterproof gel-filled wire connectors (Correct answer)
- Electrical tape only
- Alligator clips
Correct answer: Waterproof gel-filled wire connectors
Waterproof gel-filled connectors seal out moisture and prevent oxidation, making them the preferred choice for outdoor landscape lighting splices.
Question 3: When installing a path light along a garden bed, what is the ideal angle to drive the ground stake to ensure stability against lateral movement?
- Perfectly vertical at 90°
- Slightly angled away from foot traffic at 80–85° (Correct answer)
- At 45° toward the fixture
- Horizontal underground
Correct answer: Slightly angled away from foot traffic at 80–85°
Driving the stake at a slight backward angle (80–85°) gives the fixture greater resistance to being knocked sideways by foot traffic or lawn equipment.
Question 4: What is the primary purpose of using a 'home run' wiring layout instead of a daisy-chain layout in landscape lighting?
- It uses less wire overall
- It delivers more equal voltage to each fixture (Correct answer)
- It allows fixtures to be dimmed individually
- It eliminates the need for a transformer
Correct answer: It delivers more equal voltage to each fixture
A home run (hub) layout runs a dedicated wire from the transformer to each fixture or zone, minimizing voltage drop and delivering consistent brightness.
Question 5: When running low-voltage cable beneath a concrete sidewalk in a residential installation, which method is most commonly used?
- Chipping the concrete and patching
- Hydraulic boring or rigid conduit threading (Correct answer)
- Stapling cable to the underside of the slab
- Routing cable over the top and painting it
Correct answer: Hydraulic boring or rigid conduit threading
Hydraulic boring or pushing a rigid conduit sleeve beneath the slab avoids damage to the concrete and protects the cable from crushing.
Question 6: What tool is used to make a quick 'T-tap' or 'vampire' connection to an existing low-voltage landscape lighting cable without cutting it?
- Lineman's pliers
- Quick-connect piercing connector (Correct answer)
- Wire stripper
- Crimp sleeve tool
Correct answer: Quick-connect piercing connector
A quick-connect (piercing) connector bites through the cable insulation to make electrical contact without the need to cut or strip the wire.
Question 7: Which of the following installation practices best reduces glare when positioning a spotlight to illuminate a tree?
- Aim the fixture directly at the viewer from ground level
- Position the fixture behind the tree aimed upward and away from viewer sightlines (Correct answer)
- Mount the fixture at eye level on the tree trunk
- Use a wide 120° beam angle aimed horizontally
Correct answer: Position the fixture behind the tree aimed upward and away from viewer sightlines
Placing the fixture behind the tree aimed upward hides the lamp source from viewer sightlines, illuminating the canopy without causing glare.
LLC Installation Techniques 2
When installing low-voltage landscape lighting cable, what is the minimum burial depth recommended by NEC for direct-burial cable in a typical residential landscape bed?