Preventive Maintenance Procedures Flashcards

What is the recommended torque practice when re-securing fixture lens retaining rings or covers during a PM service to prevent future water infiltration?

Answer: Hand-tighten to snug, then a quarter-turn with tools to compress the gasket without cracking the housing

Over-tightening can crack plastic housings or cut gaskets, while under-tightening allows water ingress; a snug-plus-quarter-turn achieves correct gasket compression.

During a PM inspection, a technician finds that the transformer cabinet has an internal temperature noticeably higher than ambient even when the secondary load is within rated limits. What should be investigated?

Answer: Check for blocked ventilation slots, failed internal cooling components, or excessive harmonic distortion from LED drivers

Elevated transformer temperature despite normal loading often indicates blocked vents or harmonic distortion from incompatible LED drivers causing additional heat in the transformer core.

Why is it important to document 'before' and 'after' voltage readings at fixture terminals in a PM report?

Answer: To demonstrate the impact of PM work such as tap adjustments or connection repairs on system performance

Before-and-after voltage documentation proves the value of PM work by showing measurable improvements in system voltage and performance resulting from the technician's actions.

A technician is performing PM on a system with a mix of halogen and LED fixtures on the same secondary circuit. What voltage concern is most important to address?

Answer: Halogen fixtures are voltage-sensitive and may over-bright or burn out faster at voltages optimized for LEDs

Halogen lamps are highly sensitive to overvoltage; a tap setting that provides adequate voltage for LEDs at the end of a run may overpower nearby halogen fixtures, dramatically shortening their life.

What is the correct procedure for testing a landscape lighting photocell during daylight hours without waiting until dark?

Answer: Cover the photocell sensor completely to simulate darkness and verify that the transformer energizes the output circuit

Covering the photocell sensor simulates nighttime darkness, causing a properly functioning photocell to close the circuit and activate the system for verification during PM.

When replacing a copper low-voltage wire splice that has turned green and corroded underground, what additional step should the technician take beyond installing a new connector?

Answer: Clean back the corroded wire ends to expose fresh copper before making the new connection

Corroded wire ends have high resistance even after connector installation; cutting back to clean copper ensures a low-resistance connection at the repair point.

Which PM inspection item is most likely to catch a landscape lighting problem before it causes a visible failure or safety hazard?

Answer: Measuring secondary circuit amperage and comparing it to baseline to detect developing faults early

Trending amperage data reveals developing shorts, failing drivers, or unauthorized load additions before they escalate into failures, making it the most proactive PM measurement.