LLC Inspection & Quality Control 2 — Questions and Answers
Question 1: During a post-installation inspection, you discover that several path light fixtures are tilted more than 15 degrees from vertical. What is the MOST appropriate corrective action?
- Leave them as decorative angles
- Re-stake and level each fixture to within 5 degrees of vertical (Correct answer)
- Replace all fixtures with new ones
- Add more fixtures nearby to compensate
Correct answer: Re-stake and level each fixture to within 5 degrees of vertical
Fixtures tilted more than 5-10 degrees from vertical distribute light unevenly and look unprofessional; re-staking corrects the issue without replacing hardware.
Question 2: When inspecting low-voltage landscape wiring connections, which condition indicates a FAILING connection that requires immediate repair?
- Wire connectors with gel-filled interiors
- Green or white corrosion buildup on terminals (Correct answer)
- Multi-tap connectors rated for direct burial
- Connections made inside a weatherproof junction box
Correct answer: Green or white corrosion buildup on terminals
Green or white corrosion indicates oxidation that increases resistance, reduces voltage, and can cause heat buildup or fixture failure.
Question 3: A quality control check reveals that the measured voltage at the furthest fixture on a 150-foot run is 10.2V when the transformer output is 12V. What does this indicate?
- Acceptable performance within tolerance
- Excessive voltage drop requiring wire upsizing or hub relocation (Correct answer)
- A faulty transformer that needs replacement
- Normal operation for LED fixtures
Correct answer: Excessive voltage drop requiring wire upsizing or hub relocation
A drop to 10.2V (1.8V loss) on a 12V system exceeds the acceptable 10% drop threshold, indicating the wire gauge is insufficient or the run is too long.
Question 4: During an inspection, a timer-controlled transformer fails to activate at the programmed dusk time. What should be checked FIRST?
- Amperage load on each circuit
- Photocell sensor for obstruction or damage (Correct answer)
- Wire gauge of all home runs
- Junction box watertight seals
Correct answer: Photocell sensor for obstruction or damage
A blocked or damaged photocell is the most common cause of timing failures; it overrides or conflicts with the programmed schedule.
Question 5: Which inspection method BEST verifies that buried landscape wire is installed at the correct depth per NEC Article 411 requirements?
- Visual inspection of exposed wire ends
- Probing the soil with a calibrated depth rod along the wire route (Correct answer)
- Reviewing the installation invoice
- Checking wire color coding
Correct answer: Probing the soil with a calibrated depth rod along the wire route
Using a depth rod along the wire path is the only reliable field method to confirm that cable is buried at the NEC-required minimum depth of 6 inches.
Question 6: A client complains that uplighting on a tree creates a 'hot spot' with harsh glare rather than a soft wash. What QC issue does this MOST likely indicate?
- Fixture is using the wrong color temperature
- Fixture beam angle is too narrow or fixture is placed too close to the trunk (Correct answer)
- The transformer output is too high
- The wire run is too long
Correct answer: Fixture beam angle is too narrow or fixture is placed too close to the trunk
A narrow beam or fixture placed too close to the tree concentrates light rather than spreading it, creating an unpleasant hot spot.
Question 7: What is the standard practice for documenting a landscape lighting inspection to protect the contractor and satisfy client expectations?
- Verbal walk-through with the client only
- Written inspection report with photos, voltage readings, and sign-off (Correct answer)
- Email summary sent the following week
- Logging only failed items, not passing ones
Correct answer: Written inspection report with photos, voltage readings, and sign-off
A written report with photos and voltage readings creates a verifiable record for warranty purposes and demonstrates professional quality control.
LLC Inspection & Quality Control 2
During a post-installation inspection, you discover that several path light fixtures are tilted more than 15 degrees from vertical.
What is the MOST appropriate corrective action?