NABCEP PV Commissioning and Maintenance Specialist Flashcards
6 cards from real NABCEP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 NABCEP PV Commissioning and Maintenance Specialist flashcards as text
What maintenance task should be performed on PV module surfaces in dusty or arid climates more frequently than in other regions?
Answer: Cleaning to remove soiling
Dust and particulate buildup (soiling) reduces light transmission to PV cells and can significantly reduce energy output, requiring more frequent cleaning in arid climates.
During annual PV system maintenance, which component's connections should be inspected for corrosion and re-torqued to specification?
Answer: All DC and AC electrical connections
Electrical connections can loosen or corrode over time, increasing resistance and creating hot spots or arc-fault risks, so they must be inspected and torqued annually.
What is the recommended method for detecting hot spots in PV modules during a maintenance inspection?
Answer: Infrared (IR) thermography
Infrared thermography reveals thermal anomalies caused by cell cracks, bypass diode failures, or soiling that are invisible to the naked eye.
A combiner box fuse blows repeatedly in the same string position. What is the most appropriate next step?
Answer: Inspect the string for a ground fault or short circuit
A repeatedly blown fuse indicates an underlying fault such as a ground fault or short circuit in that string, which must be identified and corrected before replacing the fuse.
Which performance metric is most useful for comparing a PV system's actual output to its expected output over time?
Answer: Performance ratio (PR)
Performance ratio compares actual energy yield to the theoretically expected yield, accounting for weather, and is the standard KPI for long-term system health monitoring.
What is the primary hazard when performing maintenance on a PV array that cannot be fully de-energized by shutting off the inverter?
Answer: PV modules continue to produce DC voltage in daylight even with the inverter off
PV modules generate DC voltage whenever light hits them, so DC conductors remain energized even when the inverter and AC breakers are off, posing a shock hazard.