PV Exam Prep (PV 220)
Practice Exam
NAME: ______________________________________
DATE: __________________
For each of the following questions, choose the best answer – A, B, C, or D.
1. Which of the following is continuously monitored by an automatic transfer switch?
a. Primary power source
b. Secondary power source
c. Inverter status
d. DC voltage
2. A major feature that most grid-connected PV systems offer consumers is the ability to:
a. Store energy for backup power
b. Provide power to the electrical utility on-demand
c. Sell excess power to the neighbors
d. Send excess power to the electrical utility
3. What is meant by the term solar noon?
a. Noon (clock time), after correcting for magnetic declination at the site
b. Time of day when the sun is at its maximum altitude
c. Point at which the sun's rays are directly perpendicular to the PV array surface
d. Time of day when the PV array is at the peak of its power curve
4. Which of the following publications specifically and solely addresses issues and standards
regarding Electrical Safety in the Workplace?
a. OSHA 29 CFR 1910
b. OSHA 29 CFR 1926
c. NFPA 70
d. NFPA 70E
5. Which of the following is considered a dead load on a rooftop?
a. The weight of the workers installing a PV system
b. Vibrations from seismic activity
c. Snow
d. Wind
6. When using the American Wire Gauge (AWG) system, which of the following is the largest
conductor? a. 6 b. 8 c. 1/0 d. 2/0
PV Exam Prep (PV 220)
Practice Exam
7. Which type of inverter is most appropriate for applications with multiple roof angles and PV
module orientations?
a. Stand-alone inverter(s)
b. Grid-tied string inverter(s)
c. Microinverter(s)
d. Multimode inverter(s)
8. Which of the following is a detailed drawing that shows all PV system components, connections, and information regarding their interconnection with existing electrical
equipment/infrastructure on site, and may be required by the local permitting authority? a. Array mounting design
b. One-line diagram c. Three-line diagram d. Site drawing
9. Which of the following is the best tool to use to verify the open circuit voltage of a PV module?
a. Ammeter
b. Ohmmeter
c. Multimeter
d. Oscilloscope
10. Which PV system component is most likely to need replacement, and should be factored into the predictable maintenance costs over the life of the system?
a. Combiner box b. Inverter c. Module(s)
d. Rapid shutdown device
11. Which type of PV system requires the most maintenance regarding tilt adjustment and shading
control from nearby vegetation?
a. Building-integrated awnings
b. Ground mount array
c. Pole-mounted, dual-axis, tracking array
d. Roof mount array
12. Which component typically delineates the transition between the PV output circuit and the
inverter input circuit in a grid-tied PV system?
a. AC disconnect switch
b. DC disconnect switch
c. Combiner box
PV Exam Prep (PV 220)
Practice Exam
13. What is the leading cause of death in the construction industry?
a. Electrocution
b. Falls
c. Struck-by accidents
d. Suffocation
14. What happens to the string of PV modules when shading occurs on a module that has a bypass
diode?
a. Current increases
b. Voltage increases
c. Resistance decreases
d. Voltage decreases
15. Which of the following tilt angles is best for irradiance at solar noon during the spring equinox, for an array located at 42°N, 15°E?
a. 14° b. 27° c. 42° d. 57°
16. Which factor determines temperature ratings for an electrical conductor?
a. Length
b. Location
c. Insulation
d. Cross-sectional area
17. What UL Listing Mark (associated number) should be on an inverter used with a distributed
energy system to show that it has passed all anti-islanding tests? a. 690
b. 1547
c. 1703
d. 1741
18. Which type of mounting system is most common for residential applications with a high-pitched,
south-facing roof?
a. Ballasted mount
b. Pole mount
c. Rack mount
PV Exam Prep (PV 220)
Practice Exam
19. What is represented at point B in the I-V curve shown below?
a. VOC b. VMP c. ISC d. IMP
20. Which method is best to prevent unknowing individuals from energizing an electrical circuit
while it's being serviced?
a. Open the disconnect switch
b. Use Lockout-Tagout procedures
c. Remove the fuse(s)
d. Affix electrical tape over the handle of the circuit breaker
21. Which of the following is a fixed monthly fee that the electrical utility charges, regardless of how many kWh hours were consumed?
a. Customer charges b. Demand charges c. Energy charges
d. Net metering charges
22. Which of the following is a PV system designed to offset a customer's purchased utility energy,
and provide backup power in case of a power outage?
a. Stand-alone
b. Utility interactive
c. Multimode
d. Uninterruptible Power Supply (UPS)
23. A 120-volt pump draws three amps and runs for six hours. How many watt-hours is that?
a. 18 b. 360 c. 720 d. 2,160
PV Exam Prep (PV 220)
Practice Exam
24. For a multimode PV system, what capability must the charge controller have to ensure proper
function of the system?
a. Protect the batteries from overcharge and over-discharge
b. Prevent the array from back-feeding to the grid
c. Cool the batteries during warm weather
d. Supply current directly to the grid
25. What is the best tilt angle for summer production for an array located at 42°N latitude?
a. 27° b. 40° c. 42° d. 57°
26. Temporarily shorting the output terminals of a PV module will:
a. Destroy the module
b. Destroy the insulation on the module wiring
c. Cause damage if the module is connected in series with other PV modules
d. Have no effect on the module
27. What value increases as PV modules are connected in series?
a. Current
b. Voltage
c. Resistance
d. Irradiance
28. When using the American Wire Gauge (AWG) system, which of the following is the smallest
conductor? a. 6 b. 8 c. 1/0 d. 2/0
29. When mounting on a sloped roof, which of the following is an approved method for adding
supplemental structural support?
a. Use lag bolts to secure to plywood sheathing
b. Use roofing cement between structure pads and the roof
c. Add blocking under the roof surface between trusses/rafters
PV Exam Prep (PV 220)
Practice Exam
30. Which of the following situations would result in the most cost-effective use of a dual-axis
tracking PV array?
a. Areas of low wind, latitude less than 30°, and moderate cloud cover in the summer
months
b. Areas of low wind, latitude greater than 30°, and minimal cloud cover in the summer
months
c. Areas of moderate wind, latitude less than 30°, and moderate year-round cloud cover
d. Areas of moderate wind, latitude greater than 30°, and minimal year-round cloud cover
31. An extension ladder is used to access an upper landing 20 feet off the ground. How far should
the base of the ladder be positioned back from the point the ladder makes contact with the upper landing?
a. 4 b. 5 c. 6 d. 7
32. A site has a solar resource of 400 W/m2 for six hours. What is the cumulative Wh/m2?
a. 66.7
b. 406
c. 1,000
d. 2,400
33. In the PV industry, a fall protection system must be in place for all work done at heights in
excess of _____ feet. a. 4
b. 6 c. 8 d. 10
34. PV modules rated at Standard Test Conditions (STC) have been tested to which of the following specifications?
a. 800 w/m2 at 20°C with AM1.5
b. 1,000 w/m2 at 20°C with AM1.5
c. 1,000 w/m2 at 25°C with AM1.5
PV Exam Prep (PV 220)
Practice Exam
35. What is represented at point D in the I-V curve shown below?
a. VOC b. VMP c. ISC d. IMP
36. Inter-row spacing for a tilted PV array is determined by which of the following factors?
a. Slope and module voltage
b. Sun angle and module height
c. Sun angle and module voltage
d. Sun angle and rack manufacturer specifications
37. Employee responsibilities for PPE include:
a. Assessing the workplace for potential hazards
b. Determining when and where to use PPE
c. Providing their own PPE
d. Using PPE in accordance with training and instructions
38. The purpose of the ground-fault protection device in a PV system is to:
a. Reduce the probability of electrical shock to service personnel
b. Reduce the possibility of fire from an arcing fault to ground
c. Reduce losses of the PV output circuit to ground
d. Reduce degradation of structural supports from electrolysis
39. Which of the following would be the biggest concern about a PV array mounted at ground level?
a. Overheating of the modules
b. Electrical shock hazards from bare conductors
c. Earthquake and/or frost heave stresses on the modules
PV Exam Prep (PV 220)
Practice Exam
40. In a PV system, an insulated equipment grounding conductor 6 AWG or smaller shall be:
a. Black
b. Green
c. Red
d. White
41. A concern associated with 12-volt PV systems that use large wires to minimize voltage drop is:
a. Difficulty in obtaining DC rated disconnects with adequate current ratings
b. Difficulty in obtaining wire with DC rated insulation
c. Junction boxes, terminal blocks, or switch boxes that may too small for large wire
d. Increased likelihood that animals will chew on the wires
42. Which of the following is a common design error when using a string inverter?
a. Flexible cable used with multiple moving components
b. Use of 1/2" EMT conduit for DC circuits
c. Circuit lengths that exceed 100 ft.
d. Multiple array orientations within a single source circuit
43. When connecting and disconnecting wires while troubleshooting a PV system, the best way to
avoid electrical shock is to:
a. Inspect all questionable terminals, wear rubber gloves, and turn off all switches
b. Keep one hand behind your back, with all switches turned off, and only touch grounded
surfaces
c. Turn off switches, measure voltage and current, and wear PPE
d. Wear shoes with rubber soles, turn off all switches, and don't touch metal surfaces
44. Stainless steel hardware is most important in which of the following areas?
a. Coastal areas where the air contains salt spray
b. Desert areas where the air contains dust and sand
c. Mountainous areas where the solar spectrum contains more ultraviolet rays
d. Inland regions that are subject to freezing temperatures
45. If 5/16-inch lag screws are used to fasten a charge controller to wooden studs, an appropriate
pilot hole size would be closest to: a. 1/8”
b. 19/64” c. 7/32” d. 1/4”
PV Exam Prep (PV 220)
Practice Exam
46. An array for a stand-alone PV system is designed to produce 1.25 times the average daily load of
80 Ah. The site receives an average of four sun hours per day. If the selected PV module has an STC rating of 5A (IMP), how many paralleled strings of PV modules are required?
a. 2 b. 3 c. 4 d. 5
47. Listed PV wire is a single-conductor cable most often used:
a. From the PV array to the combiner box
b. From the combiner box to the inverter
c. From the inverter to the service panel
d. In battery banks
48. The temperature sensor for the charge controller should be connected:
a. On the side of a battery, between two batteries
b. On the side of the battery compartment
c. To the top of a battery that is at the end of a row of batteries
d. To the bottom of any battery
49. Which of the following would be a good financing option for a family that owns a home with a south-facing roof, wants to install PV, cannot currently afford the up-front installation costs, but would like to later have the option to buy?
a. Leasing
b. Power Purchase Agreement (PPA) c. Unsecured loan
d. USDA REAP loans and grants
50. At a location with a solar resource of 1,000 W/m2, the PV inverter shuts down around solar noon
for a period of time on hot days. What is the most likely design flaw to investigate first in this scenario?
a. Shading
b. Low string voltage
c. High string voltage
