LLC Troubleshooting & Diagnostics 3

Question 1

A technician suspects a wire nick caused by a lawn edger. Which tool is most appropriate for locating the exact fault point on a buried cable?

Accepted Answer

Time-domain reflectometer (TDR) or cable fault locator

Answer

A TDR sends a signal pulse and measures the time of reflection to pinpoint the exact distance to a fault in a buried cable.

Question 2

A 150-watt capacity transformer is powering fixtures that total 148 watts. Several fixtures are dim. The MOST likely cause is:

Accepted Answer

Voltage drop is occurring because the load is near the transformer's limit

Answer

Operating near maximum capacity causes increased resistance and heat in the transformer, leading to voltage drop and dim fixtures.

Question 3

After replacing a failed LED MR16 with the same wattage lamp, the new lamp flickers and fails within days. What should be investigated?

Accepted Answer

Incompatibility between the LED driver and the low-voltage transformer type (magnetic vs. electronic)

Answer

Some LED MR16 drivers require a minimum load or are incompatible with certain transformer types, causing flicker and premature failure.

Question 4

A pathway lighting zone is completely dark. The transformer's LED indicator shows the zone is active. Using a multimeter, the technician reads 12 VAC at the transformer terminal but 0 VAC mid-run. This indicates:

Accepted Answer

An open (broken) conductor exists between the transformer and the test point

Answer

Voltage present at the source but absent downstream confirms an open (break or disconnection) in the cable between those two points.

Question 5

During a service call, a technician finds that a hub-and-spoke connector has corroded wire crimp connections. The BEST long-term repair is to:

Accepted Answer

Replace the connector hub with a direct-burial-rated splice with waterproof gel caps

Answer

Direct-burial waterproof gel-filled connectors provide a reliable, moisture-resistant connection that resists future corrosion.

(LLC) Landscape Lighting Certification Practice Test

(LLC) Landscape Lighting Certification Practice Test

LLC Troubleshooting & Diagnostics 3