Practice Test Geeks(NABCEP) North American Board of Certified Energy Practitioners Solar Practice Test
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Solar PV System Design Flashcards

7 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 7 Solar PV System Design flashcards as text

  1. When designing a roof-mounted PV system, what is the primary purpose of calculating the roof's dead load capacity?

    Answer: To ensure the structure can support the added weight of the array

    Dead load capacity determines whether the existing roof structure can safely bear the static weight of the PV modules, racking, and mounting hardware.

  2. A PV array has 10 modules in series, each with a Voc of 41.2V at STC. Using NEC temperature correction for a record low of -20°C, what correction factor from Table 690.7 (for -20°C with a temperature coefficient of -0.29%/°C) would be applied?

    Answer: 1.25

    At -20°C, the NEC Table 690.7 correction factor is 1.25, accounting for increased Voc at low temperatures to ensure safe conductor and equipment ratings.

  3. What does the term 'temperature derating' mean in the context of PV module performance?

    Answer: Reducing rated output due to elevated operating temperatures

    Temperature derating reduces the expected power output of a PV module because higher temperatures decrease cell voltage and therefore total power output.

  4. In a string inverter system with three parallel strings of 12 modules each, what is the total number of modules in the array?

    Answer: 36

    Three parallel strings with 12 modules per string equals 3 × 12 = 36 total modules.

  5. Which NEC article primarily governs the installation of photovoltaic systems?

    Answer: Article 690

    NEC Article 690 specifically covers solar photovoltaic systems, including wiring, equipment, and safety requirements.

  6. A designer wants to maximize annual energy production for a fixed-tilt system in Phoenix, AZ (latitude ~33°N). What tilt angle is generally recommended?

    Answer: 33°

    For fixed-tilt arrays optimized for annual energy production, a tilt angle approximately equal to the site's latitude is commonly recommended.

  7. What is the purpose of a combiner box in a large PV array?

    Answer: To combine multiple string circuits into a single DC output

    A combiner box aggregates multiple parallel PV string circuits into one combined DC output, simplifying wiring runs to the inverter.