NABCEP NABCEP PV Commissioning and Maintenance Specialist 2

Question 1

What maintenance task should be performed on PV module surfaces in dusty or arid climates more frequently than in other regions?

Accepted Answer

Cleaning to remove soiling

Answer

Dust and particulate buildup (soiling) reduces light transmission to PV cells and can significantly reduce energy output, requiring more frequent cleaning in arid climates.

Question 2

During annual PV system maintenance, which component's connections should be inspected for corrosion and re-torqued to specification?

Accepted Answer

All DC and AC electrical connections

Answer

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.

Question 3

What is the recommended method for detecting hot spots in PV modules during a maintenance inspection?

Accepted Answer

Infrared (IR) thermography

Answer

Infrared thermography reveals thermal anomalies caused by cell cracks, bypass diode failures, or soiling that are invisible to the naked eye.

Question 4

A combiner box fuse blows repeatedly in the same string position. What is the most appropriate next step?

Accepted Answer

Inspect the string for a ground fault or short circuit

Answer

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.

Question 5

Which performance metric is most useful for comparing a PV system's actual output to its expected output over time?

Accepted Answer

Performance ratio (PR)

Answer

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.

NABCEP - North American Board of Certified Energy Practitioners Practice Test

NABCEP - North American Board of Certified Energy Practitioners Practice Test

NABCEP NABCEP PV Commissioning and Maintenance Specialist 2