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 interval is typically recommended for a full preventive maintenance inspection of a commercial grid-tied PV system?
Answer: Annually, at minimum
Industry best practice and most O&M contracts specify annual preventive maintenance inspections to catch issues before they cause significant energy loss or safety hazards.
When replacing a failed string inverter in an existing PV system, what must be verified before connecting the new unit?
Answer: DC input voltage, polarity, and AC interconnection parameters match system specs
The replacement inverter must be compatible with the system's DC voltage range, string configuration, and AC grid connection parameters to operate safely and correctly.
A monitoring system shows a sudden 20% drop in a single string's output on a clear day. Which maintenance action is most appropriate?
Answer: Inspect that string for a shaded, disconnected, or failed module
A sudden output drop in one string on a clear day indicates a localized fault — a shaded, disconnected, or failed module — that warrants immediate physical inspection.
What is the purpose of a torque wrench during PV system maintenance?
Answer: To tighten electrical and mechanical connections to manufacturer-specified torque values
Using a calibrated torque wrench ensures connections are tightened to the exact specifications required for safe, reliable operation without over- or under-tightening.
Which NEC article primarily governs the installation and maintenance safety requirements for PV systems in the US?
Answer: NEC Article 690
NEC Article 690 specifically addresses solar photovoltaic systems, covering wiring, disconnects, overcurrent protection, and safety requirements.
During maintenance, you discover arc marks inside an outdoor DC combiner box. What should you do first?
Answer: De-energize the affected circuits and identify the cause before restoring power
Arc marks indicate arcing has occurred, which is a fire and shock hazard; the affected circuits must be de-energized immediately and the root cause identified before restoring power.