Sample NABCEP Exam Questions

The following questions are representative of the difficulty and scope of the type of questions that are on the NABCEP PV Installer Exam. These questions are provided to give those preparing for the exam an understanding of the type of questions that are on the exam. There is no guaranty that any problems on the NABCEP exam will match these questions.

1. A family of four is purchasing a 5 kW net-metered utility interactive PV system for their house which is located at 30°N latitude. The family members are out of the home regularly during the following hours: Father: 9 am - 5 pm Mother: 8:30 am - 12:00 pm Children: 8:00 am - 3:00 pm While the home is unoccupied, the energy use goes to near zero. There are no shade issues at the property; competing installation costs are equal, and the year round utility rate remains constant. Which of the following orientations will produce the most annual utility savings?

a.) true south b.) true southeast c.) true southwest d.) magnetic south

2. A PV array for a utility-interactive system is to be ground mounted on a hill 1,000 feet from the point of utility connection. The single string of PV modules operates between 300 and 550 volts dc. The inverter is a 240 V inverter. There is a small building halfway between the array location and the utility point of connection. To minimize wire size, increase performance, and ensure consistent operation, where should the inverter be installed?

a.) At the PV array b.) At the midpoint building c.) At the utility point of connection d.) Midway between the PV array and the building

3. Of the following site assessment tools, which are MOST OFTEN NEEDED to determine optimal array placement?

a.) compass, level, and anemometer b.) compass, inclinometer, and irradiance meter c.) compass, digital camera, and multimeter d.) compass, inclinometer, and sun path analyzer

a.) 6.0 feet b.) 7.8 feet 4. What is the MOST IMPORTANT consideration for mounting PV arrays on residential c.) 9.6 feet rooftops with regard to energy production? d.) 15.6 feet a.) 5. Cooling What is the MOST IMPORTANT consideration for mounting PV arrays on b.) Shading residential rooftops with regard toenergy production? c.) Tilt anglea.) Cooling d.) Stand-off heightb.) Shading c.) Tilt angle 5. A homeowner wants a roof mounted solar array that produces 90% of the annual d.) Stand-off height household energy consumption of 6900 kWh. The roof has a pitch of 26° and is facing true south. The array is mounted parallel to the roof. Given an 80% system efficiency, and 6. A homeowner wants a roof mounted solar array that produces 90% of the annual the information contained in the table below, what is the array STC rating required to household energy consumption of 6900 kWh. The roof has a pitch of 26° and is facing true south. The array is mounted parallel to the roof. Given an 80% system achieve 90% of the annual energy needs?efficiency, and the information contained in the table below, what is the array STC rating required toachieve 90% of the annual energy needs? a.) 4.25 kW b.) 4.43 kW a.) 4.25 kWc.) 4.92.kW b.) 4.43 kWd.) 5.15 kW c.) 4.92 kW d.)7. 5.15 kW Which characteristic of a 500Vdc PV array gives it an advantage over a 48Vdc array of the same wattage? 6. Which characteristic of a 500 V dc PV array gives it an advantage over a 48 V dc array a.) Only one device is required for GFDI protection. of the same wattage? b.) Under low light conditions, the single source circuit configuration produces more power. a.) Only one device is required for GFDI protection.c.) Smaller conductors can be used between the array and inverter. b.) Under low light conditions, the single source circuit configuration produces more power. c.) Smaller conductors can be used between the array and inverter. d.) The maximum power tracking capability of the inverter is increased.

7. The battery bank for a battery backup utility-interactive PV system is located in a harsh environment with temperature and humidity extremes. The system charge controller has a provision for temperature compensation, but it is not connected. What is the MOST LIKELY result on the battery state of charge?

a.) Overcharged in both hot and cold weather. b.) Undercharged in both hot and cold weather. c.) Overcharged in cold weather and undercharged in hot weather. d.) Undercharged in cold weather and overcharged in hot weather.

8. What is the required minimum working space width in front of a 48 V lead acid battery bank?

a.) 24” where all live exposed parts are less than 60 V dc. b.) 30” inches or the width of the battery bank, whichever is greater. c.) 36” from the right and left edges of the battery bank. d.) 36” from the top of the ungrounded battery terminal.

9. A single inverter system requires 9 or 10 modules in series and one or two series strings in parallel. If the southeast roof is large enough for 8 modules and the southwest roof is large enough for 15 modules, which of the following array configurations results in the MOST EFFICIENT use of the PV modules installed?

a.) 15 modules on southwest roof and 5 modules on southeast roof b.) 12 modules on southwest roof and 8 modules on southeast roof c.) 10 modules on southwest roof and 5 modules on southeast roof d.) 10 modules on southwest roof and 0 modules on southeast roof

NABCEP Sample Questions: (1) a, (2) c, (3) d, (4) b, (5) b, (6) c, (7) d, (8) b, (9) d