Module 12 qs

8. The identifying feature of a diversion controller is that a. it pulses charging power to the batteries b. it opens the battery charging circuit once the process is complete C. array power is used to power another DC load once charging is complete d. each battery is charged separately, one at a time

C. array power is used to power another DC load once charging is complete

22. Solar panels degrade in power production as their temperature increases above STC of 25°C, typically at a rate of a. 0.5 percent per °C b. 1 percent per °C c. 2 percent per °C d. 2.5 percent per °C

a. 0.5 percent per C

47. The efficiency level of an inverter operating under a very small AC load relative to its total capacity a. Is usually poor b. Is extremely high Page 743 c. Is dependent upon whether the load is inductive or resistive d. Continues to decrease as more AC load is applied

a. Is usually poor

53. When determining the final factor used as the DC-to AC correction factor in array capacity calculations, the individual factors are a. Multiplied b. Added together c. Added first, then divided by the number of factors to find an average d. Divided Page 759

a. Multiplied

33. The float stage of battery charging typically begins when the battery has reached what level of charge capacity? a. Near 100 percent b. 80 to 90 percent Page 739 c. 50 percent d. 25 percent

a. Near 100 percent

43. Onc advantage to a pole-mounted array is that it a. Offers some adjustment on both the vertical and horizontal axis Page 735 b. Is limited in size only be available real estate c. Is the most accessible design for cleaning d. Is unaffected by wind

a. Offers some adjustment on both the vertical and horizontal axis Page 735

34. The maximum power point of a solar module is defined as the point where a. The product of current and voltage is at its highest b. Voltage output divided by the current is highest c. Current flow is highest and voltage is at design d. The sum of current and voltage is at its highest Page 732

a. The product of current and voltage is at its highest

13. The device used to collect battery bank power into a single, noninsulated conductor a. a busbar b. the charge controller c. the service cable d. the combiner

a. a busbar

38. Voltage drop in PV system DC interconnecting wire sizing should be limited to a. 1 percent b. 2 percent Page 749 c. 5 percent d. 7.5 percent

b. 2 percent Page 749

2. Using the equation Qty X volts X amps = AC watts X hrs/day X days/week - 7 days/ week = AC Wh per day, determine the daily AC Wh load to be considered for one 120VAC device which draws 4.5A and is in operation 9 hours per day, 5 days per week. a. 540Wh b. 3,471Wh C. 4,860Wh d. 24,300Wh

b. 3,471Wh

55. The temperature compensation feature of a charge controller monitors battery temperature and adjusts the charging voltage up or down in increments such as a. 0.5 millivolts b. 5 millivolts c. 1 volt d. 5 volts Page 740

b. 5 millivolts

30. A common depth of discharge (DOD) value used in equations for sizing a battery bank is a. 20 percent b. 50 percent c. 66 percent Page 729 d. 75 percent

b. 50 percent

27. Solar arrays can be considered a single power source for overcurrent protection as long as the design voltage does not exceed a. 25V Page 753 b. 50V c. 120V d. 240V

b. 50V

42. When combining the AC output of multiple inverters at a single load panel, Page 754 a. Each inverter must have its own means of AC disconnect b. A single means of disconnect may be installed c. Diodes must be used to prevent incorrect current flow d. Separate sources of DC power must be used

b. A single means of disconnect may be installed

36. Inverter operating temperatures above standard test conditions a. Increase the inverter's capacity Page 745 b. Decrease the inverter's capacity c. Tend to increase the inverter's efficiency d. Tend to increase the AC output voltage

b. Decrease the inverter's capacity

26. When selecting an inverter, one consistently important factor is a. Ventilation b. Efficiency Page 743 c. Data logging d. Charge control

b. Efficiency

32. A controller feature that makes use of the excess voltage produced by the array, generally wasted in the form of heat is called a. Single axis tracking Page 740 b. Maximum power point tracking c. Temperature compensation d. Pulse width modulation

b. Maximum power point tracking

50. Facing a fixed array at latitude a. Maximizes winter power production b. Provides the best balance in winter/summer performance c. Maximizes summer production d. Ensures maximum power production occurs in late afternoon Page 736

b. Provides the best balance in winter/summer performance

5. Referring to the I-V curve, solar panels produce their maximum power at what point of the curve? a. The highest value on the current axis b. The knee of the curve c. The highest value on the voltage axis d. The point where the DC system design voltage crosses the curve

b. The knee of the curve

18. Per the NEC®, solar panels must be connected in a manner which a. Allows removal of an individual panel while the system is in operation b. allows for the removal of an individual panel without interruption of a grounded conductor from another circuit c. ensures the first and last panels produced balanced power d. prevents the output voltage from drop ping below 12V

b. allows for the removal of an individual panel without interruption of a grounded conductor from another circuit

15. Using the inverter's lowest acceptable DC voltage for sizing the DC input wiring - a. prevents the wire size from being larger than necessary b. ensures the wire size is large enough to handle the current if the DC input voltage falls lower than design C. is not recommended by the NEC® d. increases the efficiency of the inverter

b. ensures the wire size is large enough to handle the current if the DC input voltage falls lower than design

21. The NEC® requires that when an inverter is removed from the circuit for service or other reason, a. another inverter must be immediately installed in its position b. jumper wires must be present to preserve the continuity of equipment and system ground wiring c. the entire PV system must be disabled d. all DC input wiring must be physically disconnected from its source

b. jumper wires must be present to preserve the continuity of equipment and system ground wiring

9. The information needed to select a non-MPPT controller includes the a. number of batteries in the bank b. number of solar panels wired in parallel c. maximum AC current load d. The desired amount of time a full charge will require

b. number of solar panels wired in parallel p740

24. One provision which is likely to be found in an interconnection agreement is a. the specified solar panel brand and size that is acceptable to the utility b. that the owner must maintain insurance against potential damage or injury the system could cause c. the maximum inverter capacity allowed d. the frequency of system inspections to be made by the utility

b. that the owner must maintain insurance against potential damage or injury the system could cause

10. Advances in inverter design and construction have allowed them to reach efficiency levels as high as a. 99 percent b.95% c. 92 percent d. 90 percent

b.95%

4. If a solar system battery is rated at a nominal capacity of 220Ah, how many hours can it be expected to deliver power at a consistent load of 11A with a 50 percent depth of discharge? a. 2 hours b. 5 hours c. 10 hours d. 20 hours

c. 10 hours p729

40. Solar module production is typically reduced at a rate of 0.5percent per "C above the STC temperature of a. 15°C b. 20°C Page 758 c. 25°C d. 77°C

c. 25°C

56. Solar battery performance is reported by the manufacturer based on a battery temperature of a. 50°F(10°F) b. 65°F(18°C) c. 77°F(25°C) d. 95°F(35°C)

c. 77°F(25°C)

7. During the bulk charge stage, batteries have typically reached a charge level of a. 45 to 55 percent b. 75 percent c. 80 to 90 percent d. 95 percent

c. 80 to 90 percent

49. Surge suppression devices Page 755 a. Are required only on arrays by the NECR b. Must have a minimum rating of 100,000 volts for PV system use c. Can be applied to either AC or DC sides of the PV system d. Absorbs surges to provide a steady voltage to the charge controller

c. Can be applied to either AC or DC sides of the PV system

41. One item typically required on both grounded and ungrounded PV arrays, with some limited exceptions, is a. PV-rated overcurrent protection b. Surge suppression c. Ground fault protection Page 754 d. PV-rated fuses

c. Ground fault protection Page 754

45. An electrical meter capable of net metering for a solar system must be able to a. Maintain a record power flow in each direction through built-in non-volatile memory b. Transmit and receive programming and shutdown instructions via Wi-Fi c. Register PV power as credit d. Provide overcurrent protection for grid wiring between the meter and the nearest transformer

c. Register PV power as credit

35. Equipment grounding conductors are typically sized according to the overcurrent protection size provided, unless a. Surge suppression has been added Page 755 b. Ground fault protection has been eliminated c. The conductors have been sized larger than required d. Equipment grounding is not required under the circumstances

c. The conductors have been sized larger than required

28. The I-V curve of a solar module compares a. Current output to solar brilliance b. Voltage output to solar brilliance Page 731 c. Voltage output to current output d. Module temperature to current output

c. Voltage output to current output

23. When calculating the needed solar array capacity for a grid-tied system without batteries, the efficiency of the inverter is_ a. not a factor that needs to be considered b. a specific factor in the equation c. compensated for as part of the DC-to-AC correction factor d. part of the mathematical calculation for the inverter selection process

c. compensated for as part of the DC-to-AC correction factor

14. The wire size for the inverter AC output is based on the a. maximum power flow from the array b. maximum power flow from the battery bank, when present c. inverter's maximum rated power output at standard test conditions d. inverter's maximum output at 40°C

c. inverter's maximum rated power output at standard test conditions

19. Where grounding of a conductor is planned for a system exceeding 50VDC, a. the positive conductor is typically chosen b. it can be grounded at several strategic locations c. it must be grounded at only one point d. the conductor color must be green

c. it must be grounded at only one point

6. Single-axis tracking systems for arrays track a. by reading solar insolation dynamically b. the sun's altitude c. the sun's azimuth d. solar position by panel temperature

c. the sun's azimuth

51. The single multiplier applied to the total array short circuit current to determine ampacity for wire sizing between solar combiners and controllers/inverters is Page 749 a. 1.25 b.1.48 c.1.56 d.2.25

c.1.56

29. The NECR requires that battery banks must be equipped with a means of disconnect to separate groups of batteries when the DC system design voltage exceeds a. 6 volts Page 727 b. 12 volts c. 24 volts d. 48 volts

d. 48 volts

25. An inverter's rated output current is 60A. What is the maximum size overcurrent protective device that can be installed? a. 48A b. 52A c. 60A d. 75A

d. 75A

48.An inverter's rated output current is 60A. What is the maximum size overcurrent protective device that can be installed? a. 48A Page 764 b. 52A c. 60A d. 75A

d. 75A

54. The DC-to-AC correction factor used in calculating the needed solar array capacity for battery-free, grid-tied systems includes a. A correction factor for the temperature difference between STC and actual conditions b. An extra +10 percent simply to ensure the array is large enough c. A factor to compensate for an average number of cloudy days d. A correction factor to compensate for module age Page 759

d. A correction factor to compensate for module age Page 759

11. The primary information required for selection of an inverter for a stand-alone PV system is a. AC load wattage, individual solar panel voltage, AC output voltage, and AC frequency b. AC load wattage, DC input voltage, AC output voltage, and the array short circuit current c. DC load wattage, DC output voltage, AC input voltage, and AC frequency d. AC load wattage, DC input voltage, AC output voltage, and AC frequency

d. AC load wattage, DC input voltage, AC output voltage, and AC frequency

44. What would be the effect on the DC system current flow if the DC voltage of the system is doubled? a. Current flow is doubled Page 727 b. Current flow is quadrupled c. Current flow is reduced by 25 percent d. Current flow is reduced by 50 percent

d. Current flow is reduced by 50 percent

39. An interconnection agreement a. Documents the details of installation between the owner and the PV system contractor b. Outlines the agreement between the PV system contractor and the utility c. Specifies the minimum amount of power the system must generate daily d. Documents the details of grid connection between the utility and the system owner Page 763

d. Documents the details of grid connection between the utility and the system owner Page 763

37. In this equation used in charge controller selection (module short circuit current x number of modules in parallel) x 1.25 = array short circuit amps, the 1.25 multiplier a. Allows for additional capacity for future expansion of the battery bank b.Compensates for potentially high battery temperatures c. Compensates for potentially higher solar module temperatures d. Provides a safety factor in the controller's ability to handle the array short circuit Page 741

d. Provides a safety factor in the controller's ability to handle the array short circuit Page 741

31. Interconnecting wires between batteries in a bank a. Must be THWN b. Should be sunlight resistant fag c. Should be the same size as the controller DC input wiring d. Should be the same gauge and length

d. Should be the same gauge and length

52. What stage of battery charging is true with regard to gel batteries? Page 739 a. They should not experience an absorption stage b. They should not experience a float stage c. They should not experience a bulk charge stage d. They should not experience an equalization stage

d. They should not experience an equalization stage

46. The inverter AC output for a grid-tied residential system would typically be connected a. At the line side of the meter base b. At the load side of the meter base Page 752 c. Directly to the utility external disconnect switch d. To the load side of a dedicated circuit breaker in the main distribution panel

d. To the load side of a dedicated circuit breaker in the main distribution panel

1.The types of electrical loads that PV systems can provide power for include a. only DC electrical loads b. only AC electrical loads c. only those loads which operate during the day d. both AC and DC loads

d. both AC and DC loads

3. Changing the DC system design voltage from 12V to 48V has the effect of _ a. increasing current flow by a factor of 2 b. increasing current flow by a factor of 4 c. decreasing current flow by 50 percent d. decreasing current flow by 75 percent

d. decreasing current flow by 75 percent

12. When determining the wire sizing ampacity for the connection of power from the solar combiner box to either a controller or inverter, a unique multiplier of 1.56 is applied to the array short circuit current to a. compensate for an anticipated long wiring run b. allow for future expansion of the array C. compensate for the exposure to sunlight d. derate to 80 percent plus compensate for periods of extreme insolation

d. derate to 80 percent plus compensate for periods of extreme insolation

16. The NEC® specifies that arrays that are designed to provide voltages in excess of 50V a. can be protected by a single overcurrent protective device b. be installed with a means of disconnect for each individual panel c. be labeled as a high-voltage array d. incorporate panel fuses as well as an overcurrent protective device for the full array

d. incorporate panel fuses as well as an overcurrent protective device for the full array

20. Equipment grounding is required a. on all systems operating in excess of 50VDC b. on all systems operating in excess of 15VDC c. on grid-tied systems only d. on all systems, regardless of voltage

d. on all systems, regardless of voltage

17. In stand-alone PV systems, the main breaker of the load panel_ a. will be sized based on the same ampicity value used to size the inverter AC output wiring b. is sized to handle the total of the connected loads c. is sized to match the capacity of the pan d. will be sized to the total of the connected loads, multiplied by 1.25

d. will be sized to the total of the connected loads, multiplied by 1.25