NABCEP PV ASSOCIATE ACTUAL EXAM PRACTICE QUESTIONS WITH EXPERT GRADED A+ ANSWERS

NABCEP PV ASSOCIATE ACTUAL EXAM PRACTICE QUESTIONS WITH EXPERT GRADED A+ ANSWERS 1. An off-grid installation has a 1HP pump that is on 10% of the time and a 20W light that is on 100% of the time. What is the monthly energy use? - ANSWER 68KWh 1HP = 746W 746W * 0.1 * 24hours * 30days = 53712Wh 20W * 24hrs * 30days = 14400Wh 14400 + 53712 = 68112Wh 68kWh 2. What kind of ground faults do most inverters detect? - ANSWER DC Inverters detect dc ground faults. AC ground faults are detected on the AC side of the inverter at the distribution paned (MSP, load center). Most inverters are not connected to high or medium voltage. Medium voltage is thousands of volts, large utility scale inverters are connected to medium voltage via a transformer 3. Parallel PV circuit connections increase - ANSWER Parallel increase current. Series increase voltage 4. Optimal tilt for off-grid PV system in the winter - ANSWER Latitude + 15 degrees is Optimal tilt to maximize winter production. The sun is lower in the winter, requiring a higher tilt angle 5. What is the most acceptable rating of an enclosure for exposed circuit conductors mounted on an outside wall? - ANSWER NEMA 3R 6. Bypass diodes are located in the A) Combiner box B) Inverter C) Wiring harness D) PV Module - ANSWER Bypass diodes are in PV module junction box. Diverts current around a group of cells if one is shaded. Usually 3 diodes/PV module 7. PV array at higher elevation would tend to produce more - ANSWER Current. Higher elevation, less atmosphere, more irradiance, more current. High elevation can also be cooler meaning more voltage from cold temps. 8. How much 14% efficient PV fits on 25 Square Meters A) 3000W B) 4.5kW C) 4000W D) 3.5kW - ANSWER D) 3.5kW. 14% efficient = 0.14*1000W/M^2 = 140 W/m^2 140 * 25 = 3500W = 3.5kW 9. Which is the smallest conductor? - ANSWER 18 AWG 18 AWG, 10 AWG, 0 AWG, 3/0 AWG 10. What is the simplest type of PV system - ANSWER Direct coupled is the simplest with just PV and a load that only works when the sun is out 11. Sun path charts differ based on - ANSWER Latitude 12. Series connections increase - ANSWER Voltage. Parallel increases current 13. The longest shadow at 2PM would be on - ANSWER The winter solstice (12/21) 14. Current carrying ability of a conductor (wire) is called - ANSWER Ampacity 15. According to ohms law and voltage drop, the relationship between voltage drop and current is - ANSWER Proportional. Ohms law: V = I*R More current makes more voltage drop. This is a reason why we need a larger wire with more current, so the wire resistance is less with a larger wire and there will be less voltage drop. 16. An array in a hot and dry place is not producing as expected in summer time. Which of the following is NOT a likely problem: a) Decreased ac wire size and voltage loss b) String size too short B) String size too long C) Soiling - ANSWER C) String size too short. When it is hot, voltage can be low. Too long of a string would be a problem when it is too cold not too hot. 17. When using a digital multimeter, what is the first thing you should do? - ANSWER Inspect the meter. Always inspect first, look before you touch 18. is the worst design error? A) BIPV on a commercial job B) A fast-growing tree to the north of an array in Idaho C) PV at 5-degree tilt at 40 degrees latitude D) Different tilt angles in a PV source circuit - ANSWER D) Different tilt or azimuth operation within a source circuit is bad. Series connections should not have different orientations 19. MPPT is for - ANSWER MPPT is maximum power point tracking and will optimize the energy harnessed from PV. Some inverters have multiple MPPTs. Charge controllers often, but don't always, have MPPTs 20. Concentrated PV: A) Only works with direct sunlight B) Usually has a single axis tracker C) Will get 30% power during cloudy conditions D) Is using heat to make electricity - ANSWER A) Only works in direct sunlight. usually works with 2-axis trackers to always point at the sun and will not work at all in cloudy conditions. Concentrated PV =! Concentrating Solar thermal 21. Fall protection should be used at heights over - ANSWER 6 feet 22. What is the ground mount advantage over a rooftop system? - ANSWER Ground mount is cooler hat rooftop because of better airflow, meaning higher voltage 23. Which test conditions have higher voltage? STC PTC CEC NOCT - ANSWER STC is higher voltage