LA 4-50 Solar Energy Equipment Installer Exam Questions and Correct
Answers (Verified Answers) Plus Rationales
Question 1: What is the primary function of a photovoltaic (PV) cell?
A. To store electrical energy B. To convert sunlight directly into electricity C. To convert AC
power to DC power D. To regulate voltage levels
CORRECT ANSWER: B. To convert sunlight directly into electricity
Rationale: Photovoltaic cells are semiconductor devices that generate direct current (DC)
electricity when exposed to photons from sunlight through the photovoltaic effect. They do
not store energy or convert AC to DC.
Question 2: In Louisiana, which agency is primarily responsible for licensing
electrical contractors who install solar systems?
A. Louisiana Department of Natural Resources B. Louisiana State Licensing Board for
Contractors (LSLBC) C. Louisiana Public Service Commission D. Louisiana Office of Energy
CORRECT ANSWER: B. Louisiana State Licensing Board for Contractors (LSLBC)
Rationale: The LSLBC regulates commercial and residential building contractors, including
those performing electrical work. Solar installation often involves electrical wiring,
requiring appropriate licensing under LSLBC regulations.
Question 3: What does NEC Article 690 specifically cover?
A. Wind Energy Systems B. Solar Photovoltaic Systems C. Battery Storage Systems D. Fuel
Cell Systems
CORRECT ANSWER: B. Solar Photovoltaic Systems
Rationale: Article 690 of the National Electrical Code (NEC) is dedicated to the installation
requirements for Solar Photovoltaic Systems, covering circuits, disconnects, grounding, and
labeling.
Question 4: What is the standard test condition (STC) temperature for rating PV
modules?
A. 0°C B. 25°C C. 40°C D. 100°C
CORRECT ANSWER: B. 25°C
Rationale: Standard Test Conditions (STC) define the baseline for module performance
ratings: 1000 W/m² irradiance, air mass 1.5 spectrum, and a cell temperature of 25°C (77°F).
Question 5: Which component is required to convert DC electricity from solar panels
into AC electricity for home use?
,A. Charge Controller B. Inverter C. Combiner Box D. Disconnect Switch
CORRECT ANSWER: B. Inverter
Rationale: Solar panels produce Direct Current (DC). Most household appliances and the
utility grid operate on Alternating Current (AC). The inverter performs this conversion.
Question 6: What is the purpose of a rapid shutdown system in a PV array?
A. To maximize energy production B. To reduce voltage on conductors inside the array
boundary for firefighter safety C. To prevent battery overcharging D. To disconnect the
system from the grid during outages
CORRECT ANSWER: B. To reduce voltage on conductors inside the array boundary for
firefighter safety
Rationale: NEC 690.12 requires rapid shutdown systems to de-energize PV system
conductors within the array boundary quickly, reducing shock hazards for emergency
responders.
Question 7: In a series circuit of PV modules, what happens to the voltage and current?
A. Voltage adds up; current remains the same B. Current adds up; voltage remains the same
C. Both voltage and current add up D. Both voltage and current remain the same
CORRECT ANSWER: A. Voltage adds up; current remains the same
Rationale: When modules are connected in series, the voltages of individual modules sum
together, while the current flowing through the string is limited to the lowest current-
producing module.
Question 8: What is the minimum working space depth required in front of electrical
equipment operating at 150 volts or less to ground?
A. 2 feet B. 3 feet C. 4 feet D. 5 feet
CORRECT ANSWER: B. 3 feet
Rationale: NEC 110.26(A)(1) requires a minimum clear working space of 3 feet (900 mm) in
depth for equipment operating at 150 volts or less to ground.
Question 9: Which type of inverter is best suited for roofs with multiple orientations or
shading issues?
A. String Inverter B. Microinverter C. Central Inverter D. Off-grid Inverter
CORRECT ANSWER: B. Microinverter
,Rationale: Microinverters are attached to individual panels, allowing each panel to operate
independently. This mitigates the impact of shading or orientation differences that would
otherwise drag down the performance of an entire string.
Question 10: What is the "Point of Common Coupling" (PCC)?
A. The connection point between the solar array and the inverter B. The point where the
customer’s wiring connects to the utility grid C. The grounding electrode connection D. The
battery bank terminal
CORRECT ANSWER: B. The point where the customer’s wiring connects to the utility grid
Rationale: The PCC is the interface between the utility distribution network and the
customer’s premises wiring. It is critical for interconnection agreements and safety.
Question 11: Why is aluminum conduit often preferred over PVC for outdoor solar
installations in Louisiana?
A. It is cheaper B. It provides better UV protection and physical durability C. It is easier to
cut D. It is non-conductive
CORRECT ANSWER: B. It provides better UV protection and physical durability
Rationale: While PVC is UV resistant if rated, metal conduits like EMT or Aluminum offer
superior physical protection against impact and weathering in harsh outdoor environments,
though proper grounding is required. Note: PVC Schedule 80 is also common, but metal is
often preferred for mechanical strength.
Question 12: What is the maximum voltage allowed for a one-family dwelling PV
system under NEC 690.7?
A. 300 volts B. 600 volts C. 1000 volts D. 1500 volts
CORRECT ANSWER: B. 600 volts
Rationale: NEC 690.7 limits the maximum voltage of PV systems in one- and two-family
dwellings to 600 volts. Commercial systems may go up to 1000V or 1500V depending on the
code cycle and equipment listing.
Question 13: What is the function of a charge controller in an off-grid system?
A. To convert DC to AC B. To regulate the voltage and current coming from the panels to the
battery C. To measure energy production D. To disconnect the grid
CORRECT ANSWER: B. To regulate the voltage and current coming from the panels to the
battery
, Rationale: Charge controllers prevent batteries from overcharging and overheating by
regulating the input from the PV array. They also prevent reverse current flow at night.
Question 14: Which document outlines the specific interconnection requirements for
utilities in Louisiana?
A. The National Electrical Code B. The Utility’s Interconnection Tariff or Agreement C. The
Building Code D. The Manufacturer’s Warranty
CORRECT ANSWER: B. The Utility’s Interconnection Tariff or Agreement
Rationale: Each utility company in Louisiana has specific technical and procedural
requirements for connecting distributed generation sources to their grid, detailed in their
interconnection tariffs.
Question 15: What is "net metering"?
A. Measuring the net weight of solar panels B. A billing mechanism where customers receive
credit for excess electricity sent to the grid C. Measuring the efficiency of the inverter D. A
method of grounding the system
CORRECT ANSWER: B. A billing mechanism where customers receive credit for excess
electricity sent to the grid
Rationale: Net metering allows solar owners to feed excess electricity back into the grid and
receive credits on their utility bill, offsetting the cost of electricity drawn from the grid when
solar production is low.
Question 16: What is the primary hazard associated with DC arcs in solar systems?
A. They are easily extinguished B. They can sustain themselves and cause fires C. They only
occur at night D. They are harmless to humans
CORRECT ANSWER: B. They can sustain themselves and cause fires
Rationale: Unlike AC arcs, which cross zero voltage 120 times per second and self-
extinguish, DC arcs can sustain continuously, generating intense heat that can ignite
surrounding materials.
Question 17: When installing roof mounts, what is the most critical factor to ensure
roof integrity?
A. The color of the mount B. Proper flashing and waterproofing at penetration points C.
Using the longest screws possible D. Painting the mounts
CORRECT ANSWER: B. Proper flashing and waterproofing at penetration points
Answers (Verified Answers) Plus Rationales
Question 1: What is the primary function of a photovoltaic (PV) cell?
A. To store electrical energy B. To convert sunlight directly into electricity C. To convert AC
power to DC power D. To regulate voltage levels
CORRECT ANSWER: B. To convert sunlight directly into electricity
Rationale: Photovoltaic cells are semiconductor devices that generate direct current (DC)
electricity when exposed to photons from sunlight through the photovoltaic effect. They do
not store energy or convert AC to DC.
Question 2: In Louisiana, which agency is primarily responsible for licensing
electrical contractors who install solar systems?
A. Louisiana Department of Natural Resources B. Louisiana State Licensing Board for
Contractors (LSLBC) C. Louisiana Public Service Commission D. Louisiana Office of Energy
CORRECT ANSWER: B. Louisiana State Licensing Board for Contractors (LSLBC)
Rationale: The LSLBC regulates commercial and residential building contractors, including
those performing electrical work. Solar installation often involves electrical wiring,
requiring appropriate licensing under LSLBC regulations.
Question 3: What does NEC Article 690 specifically cover?
A. Wind Energy Systems B. Solar Photovoltaic Systems C. Battery Storage Systems D. Fuel
Cell Systems
CORRECT ANSWER: B. Solar Photovoltaic Systems
Rationale: Article 690 of the National Electrical Code (NEC) is dedicated to the installation
requirements for Solar Photovoltaic Systems, covering circuits, disconnects, grounding, and
labeling.
Question 4: What is the standard test condition (STC) temperature for rating PV
modules?
A. 0°C B. 25°C C. 40°C D. 100°C
CORRECT ANSWER: B. 25°C
Rationale: Standard Test Conditions (STC) define the baseline for module performance
ratings: 1000 W/m² irradiance, air mass 1.5 spectrum, and a cell temperature of 25°C (77°F).
Question 5: Which component is required to convert DC electricity from solar panels
into AC electricity for home use?
,A. Charge Controller B. Inverter C. Combiner Box D. Disconnect Switch
CORRECT ANSWER: B. Inverter
Rationale: Solar panels produce Direct Current (DC). Most household appliances and the
utility grid operate on Alternating Current (AC). The inverter performs this conversion.
Question 6: What is the purpose of a rapid shutdown system in a PV array?
A. To maximize energy production B. To reduce voltage on conductors inside the array
boundary for firefighter safety C. To prevent battery overcharging D. To disconnect the
system from the grid during outages
CORRECT ANSWER: B. To reduce voltage on conductors inside the array boundary for
firefighter safety
Rationale: NEC 690.12 requires rapid shutdown systems to de-energize PV system
conductors within the array boundary quickly, reducing shock hazards for emergency
responders.
Question 7: In a series circuit of PV modules, what happens to the voltage and current?
A. Voltage adds up; current remains the same B. Current adds up; voltage remains the same
C. Both voltage and current add up D. Both voltage and current remain the same
CORRECT ANSWER: A. Voltage adds up; current remains the same
Rationale: When modules are connected in series, the voltages of individual modules sum
together, while the current flowing through the string is limited to the lowest current-
producing module.
Question 8: What is the minimum working space depth required in front of electrical
equipment operating at 150 volts or less to ground?
A. 2 feet B. 3 feet C. 4 feet D. 5 feet
CORRECT ANSWER: B. 3 feet
Rationale: NEC 110.26(A)(1) requires a minimum clear working space of 3 feet (900 mm) in
depth for equipment operating at 150 volts or less to ground.
Question 9: Which type of inverter is best suited for roofs with multiple orientations or
shading issues?
A. String Inverter B. Microinverter C. Central Inverter D. Off-grid Inverter
CORRECT ANSWER: B. Microinverter
,Rationale: Microinverters are attached to individual panels, allowing each panel to operate
independently. This mitigates the impact of shading or orientation differences that would
otherwise drag down the performance of an entire string.
Question 10: What is the "Point of Common Coupling" (PCC)?
A. The connection point between the solar array and the inverter B. The point where the
customer’s wiring connects to the utility grid C. The grounding electrode connection D. The
battery bank terminal
CORRECT ANSWER: B. The point where the customer’s wiring connects to the utility grid
Rationale: The PCC is the interface between the utility distribution network and the
customer’s premises wiring. It is critical for interconnection agreements and safety.
Question 11: Why is aluminum conduit often preferred over PVC for outdoor solar
installations in Louisiana?
A. It is cheaper B. It provides better UV protection and physical durability C. It is easier to
cut D. It is non-conductive
CORRECT ANSWER: B. It provides better UV protection and physical durability
Rationale: While PVC is UV resistant if rated, metal conduits like EMT or Aluminum offer
superior physical protection against impact and weathering in harsh outdoor environments,
though proper grounding is required. Note: PVC Schedule 80 is also common, but metal is
often preferred for mechanical strength.
Question 12: What is the maximum voltage allowed for a one-family dwelling PV
system under NEC 690.7?
A. 300 volts B. 600 volts C. 1000 volts D. 1500 volts
CORRECT ANSWER: B. 600 volts
Rationale: NEC 690.7 limits the maximum voltage of PV systems in one- and two-family
dwellings to 600 volts. Commercial systems may go up to 1000V or 1500V depending on the
code cycle and equipment listing.
Question 13: What is the function of a charge controller in an off-grid system?
A. To convert DC to AC B. To regulate the voltage and current coming from the panels to the
battery C. To measure energy production D. To disconnect the grid
CORRECT ANSWER: B. To regulate the voltage and current coming from the panels to the
battery
, Rationale: Charge controllers prevent batteries from overcharging and overheating by
regulating the input from the PV array. They also prevent reverse current flow at night.
Question 14: Which document outlines the specific interconnection requirements for
utilities in Louisiana?
A. The National Electrical Code B. The Utility’s Interconnection Tariff or Agreement C. The
Building Code D. The Manufacturer’s Warranty
CORRECT ANSWER: B. The Utility’s Interconnection Tariff or Agreement
Rationale: Each utility company in Louisiana has specific technical and procedural
requirements for connecting distributed generation sources to their grid, detailed in their
interconnection tariffs.
Question 15: What is "net metering"?
A. Measuring the net weight of solar panels B. A billing mechanism where customers receive
credit for excess electricity sent to the grid C. Measuring the efficiency of the inverter D. A
method of grounding the system
CORRECT ANSWER: B. A billing mechanism where customers receive credit for excess
electricity sent to the grid
Rationale: Net metering allows solar owners to feed excess electricity back into the grid and
receive credits on their utility bill, offsetting the cost of electricity drawn from the grid when
solar production is low.
Question 16: What is the primary hazard associated with DC arcs in solar systems?
A. They are easily extinguished B. They can sustain themselves and cause fires C. They only
occur at night D. They are harmless to humans
CORRECT ANSWER: B. They can sustain themselves and cause fires
Rationale: Unlike AC arcs, which cross zero voltage 120 times per second and self-
extinguish, DC arcs can sustain continuously, generating intense heat that can ignite
surrounding materials.
Question 17: When installing roof mounts, what is the most critical factor to ensure
roof integrity?
A. The color of the mount B. Proper flashing and waterproofing at penetration points C.
Using the longest screws possible D. Painting the mounts
CORRECT ANSWER: B. Proper flashing and waterproofing at penetration points
