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NABCEP PVSI practice questions

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Question 1Knowledge of applicable codes and ordinances

A residential rooftop PV array is installed on a dwelling in the United States. Which code document is the primary source for the structural and electrical requirements that the AHJ will enforce?

  1. The utility's interconnection tariff only
  2. The manufacturer's installation manual alone, regardless of local adoption
  3. The National Electrical Code (NFPA 70), as adopted by the local jurisdiction Correct answer.
  4. The PV module datasheet only

Explanation

The NEC is the model electrical code most US jurisdictions adopt and enforce for PV systems, and the AHJ inspects to the locally adopted edition. Manufacturer instructions must also be followed, but they supplement rather than replace the adopted code. Utility tariffs govern interconnection, not electrical installation safety.

Question 2Knowledge of applicable codes and ordinances

Under the NEC, PV system conductors that operate at over 1000 volts nominal are governed by which article?

  1. Article 250
  2. Article 705
  3. Article 690
  4. Article 691 Correct answer.

Explanation

Article 691 covers large-scale PV electric power production facilities operating at over 1000 volts, while Article 690 addresses PV systems at 1000 volts or less. Article 705 covers interconnection of power production sources, and Article 250 covers grounding and bonding.

Question 3Knowledge of applicable codes and ordinances

A PV source circuit has a calculated maximum current of 12.5 A after applying the 1.25 factor. What is the minimum ampacity required for the conductors of that circuit before any adjustment for conditions of use?

  1. 15.6 A
  2. 10.0 A
  3. 20.0 A
  4. 12.5 A Correct answer.

Explanation

PV source and output circuit conductors must have an ampacity of at least 125 percent of the maximum current, and that 125 percent factor has already been applied to reach 12.5 A. No additional multiplier is required for the base ampacity. Further adjustment applies only for conditions of use such as temperature or conduit fill.

Question 4Knowledge of applicable codes and ordinances

Which standard size overcurrent device is the minimum permitted to protect a PV source circuit with a calculated maximum current of 9.6 A where the device must be rated at least 125 percent of that current?

  1. 20 A
  2. 12 A
  3. 10 A
  4. 15 A Correct answer.

Explanation

Multiplying 9.6 A by 1.25 gives 12 A, and the next standard ampere rating not less than that value is 15 A. Standard ratings include 10, 15, 20, 25, and 30 A, so 12 A is not a standard size. The device must be at least 12 A, making 15 A the minimum standard rating.

Question 5Knowledge of applicable codes and ordinances

What is the maximum direct-current voltage permitted for a one- and two-family dwelling PV system under the NEC?

  1. 48 V
  2. 1000 V Correct answer.
  3. 1500 V
  4. 600 V

Explanation

PV systems on one- and two-family dwellings are limited to a maximum direct-current system voltage of 1000 V under Article 690. Higher DC voltages are permitted only for other occupancies and conditions. The 1500 V allowance applies to qualifying large-scale facilities, not dwellings.

Question 6Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling roof. Which marking is required at the DC disconnect and at the point of interconnection to warn first responders?

  1. A placard stating the array tilt angle
  2. A placard identifying the system as a photovoltaic power source with the rated system voltage Correct answer.
  3. A placard listing only the module manufacturer and model
  4. A placard showing the utility account number

Explanation

The NEC requires a permanent plaque or directory at the disconnecting means and at the service equipment identifying the PV power source and its rated system voltage. This alerts firefighters and electricians to energized conductors that may remain live. Manufacturer, account, and tilt information are not the required warning content.

Question 7Knowledge of applicable codes and ordinances

PV source circuit conductors installed on a rooftop are run in exposed locations subject to sunlight. Which requirement applies to the conductor insulation?

  1. It must be rated for at least 2000 V
  2. It must be listed as sunlight resistant Correct answer.
  3. It must be rated for direct burial
  4. It must be listed as moisture resistant only

Explanation

Conductors exposed to direct sunlight must be listed or marked as sunlight resistant to prevent insulation degradation. Moisture resistance and burial ratings address different environmental conditions. Voltage rating is separate from the sunlight exposure requirement.

Question 8Knowledge of applicable codes and ordinances

A disconnect for a PV system is installed outdoors on a dwelling. Which requirement applies to the disconnect's accessibility?

  1. It may be installed in a locked room without ready access
  2. It must be readily accessible Correct answer.
  3. It must be accessible only to qualified persons
  4. It may be installed behind a locked fence without a key

Explanation

PV system disconnects must be readily accessible so they can be reached quickly for service and emergency shutdown. Readily accessible means no obstacles, locks, or tools are needed to reach the device. Restricting access to qualified persons or locking it away defeats this requirement.

Question 9Knowledge of applicable codes and ordinances

A utility-interactive inverter is installed in a residence. Which requirement applies to the inverter's output circuit connection to the load side of the service disconnect?

  1. The connection may be made with a cord and plug
  2. The connection may be made with a wire nut splice
  3. The connection must be made with a dedicated circuit breaker or fused disconnect rated for the inverter output Correct answer.
  4. The connection may be made with a standard receptacle

Explanation

Utility-interactive inverters must be connected through a dedicated overcurrent device or disconnect rated for the inverter output current. Cord-and-plug or receptacle connections are not permitted for this permanent power source. Wire nut splices do not provide the required overcurrent protection.

Question 10Knowledge of applicable codes and ordinances

A PV system is connected to the load side of the service disconnect in a dwelling. What is the maximum permitted sum of the inverter output ratings relative to the busbar rating?

  1. The sum of inverter output ratings must not exceed 120 percent of the busbar rating Correct answer.
  2. The sum of inverter output ratings must not exceed the service conductor ampacity
  3. The sum of inverter output ratings must not exceed the busbar rating
  4. The sum of inverter output ratings must not exceed 50 percent of the busbar rating

Explanation

For load-side connections, the sum of the inverter output ratings is limited to 120 percent of the busbar rating when the main breaker plus the inverter source breaker does not exceed the busbar rating. This allowance recognizes that PV output rarely coincides with full service load. The 50 percent and service conductor limits are not the governing rule.

Question 11Knowledge of applicable codes and ordinances

A PV system is installed on a commercial building. Which requirement applies to the rapid shutdown of PV system conductors?

  1. Conductors more than 1 foot from the array must be reduced to 80 V within 30 seconds
  2. Conductors more than 1 foot from the array must be reduced to 30 V within 30 seconds Correct answer.
  3. Conductors more than 1 foot from the array must be reduced to 30 V within 10 seconds
  4. Conductors more than 1 foot from the array must be reduced to 600 V within 30 seconds

Explanation

Rapid shutdown requirements for PV systems on buildings require conductors more than 1 foot from the array to be reduced to 30 V or less within 30 seconds of shutdown initiation. This limit protects firefighters operating on the roof. The other voltage and time values do not match the code requirement.

Question 12Knowledge of applicable codes and ordinances

A PV array is mounted on a roof with a slope of 4 inches per foot. What is the minimum required clearance between the array and the roof surface for the purposes of firefighter access and module ventilation?

  1. 12 inches
  2. 3 inches
  3. 6 inches Correct answer.
  4. 4 inches

Explanation

The NEC and related installation standards require a minimum 6-inch clearance between the PV array and the roof surface for roof-mounted arrays. This allows ventilation and access beneath the modules. Smaller clearances do not meet the requirement, and 12 inches exceeds the minimum.

Question 13Knowledge of applicable codes and ordinances

A residential PV system uses a string inverter with a DC disconnect mounted next to the inverter. Where must the DC disconnect be located relative to the inverter?

  1. Within sight of the inverter and readily accessible Correct answer.
  2. At the utility meter only
  3. Anywhere on the property as long as it is labeled
  4. Inside the inverter enclosure only

Explanation

The DC disconnect must be within sight of the inverter and readily accessible so service personnel can isolate the DC source before working on the inverter. A remote or unlabeled location does not satisfy this requirement. Placing it only inside the inverter or at the meter does not meet the within-sight rule.

Question 14Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that has adopted the 2020 NEC. Which article governs the interconnection of the PV system with the utility supply?

  1. Article 705 Correct answer.
  2. Article 300
  3. Article 250
  4. Article 690

Explanation

Article 705 covers interconnection of electric power production sources, including PV systems operating in parallel with the utility supply. Article 690 covers PV-specific requirements, while Article 250 covers grounding and Article 300 covers general wiring methods. The interconnection rules are found in Article 705.

Question 15Knowledge of applicable codes and ordinances

A PV module has a rated open-circuit voltage of 45.0 V and a temperature coefficient of -0.30 percent per degree Celsius. At a record low temperature of -10 degrees Celsius, what is the approximate maximum system voltage contribution of one module?

  1. 49.5 V Correct answer.
  2. 45.0 V
  3. 47.7 V
  4. 46.4 V

Explanation

Using the standard 25 degrees Celsius rating reference, the temperature drop is 35 degrees. The increase is 45.0 × 0.003 × 35 = 4.725 V, giving 49.725 V. The closest listed approximation is 49.5 V; the calculated value rounds to 49.7 V and should not be rounded down for a design limit.

Question 16Knowledge of applicable codes and ordinances

A PV system is installed on a commercial building with a flat roof. Which requirement applies to the marking of the DC conductors at the point where they enter the building?

  1. They must be marked with the maximum DC voltage and the available fault current Correct answer.
  2. They must be marked with the module tilt angle
  3. They must be marked with the installer's license number
  4. They must be marked with the utility meter number

Explanation

DC conductors entering a building must be marked to indicate the maximum DC voltage and available fault current so that workers can identify the hazard. This marking supports safe isolation and servicing. Tilt angle, license number, and meter number are not the required content.

Question 17Knowledge of applicable codes and ordinances

A PV system uses a microinverter on each module. Which requirement applies to the AC output conductors of the microinverters?

  1. They must be sized for the inverter DC input current
  2. They must be sized for at least 125 percent of the microinverter output current Correct answer.
  3. They must be sized for the module short-circuit current
  4. They must be sized for the array maximum power current

Explanation

Microinverter AC output conductors must be sized for at least 125 percent of the microinverter's rated output current. The DC-side module current does not govern the AC branch conductors. Sizing to the module short-circuit or maximum power current would misapply the DC values to the AC circuit.

Question 18Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling with a 200 A service panel and a 200 A busbar. The main breaker is 200 A. What is the maximum total inverter output rating permitted for a load-side connection?

  1. 120 A
  2. 200 A
  3. 80 A
  4. 40 A Correct answer.

Explanation

The load-side allowance permits the sum of inverter output ratings up to 120 percent of the busbar rating, or 240 A, minus the 200 A main breaker, leaving 40 A. This ensures the combined sources do not exceed the busbar rating. Larger values would exceed the busbar limit.

Question 19Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that requires a building permit. Which document typically must be submitted with the permit application?

  1. A set of plans showing the system layout, electrical single-line diagram, and equipment ratings Correct answer.
  2. A copy of the installer's insurance certificate only
  3. A copy of the module warranty only
  4. A copy of the homeowner's utility bill only

Explanation

Permit applications generally require plans that show the array layout, electrical single-line diagram, and equipment ratings so the AHJ can verify code compliance. Utility bills, warranties, and insurance certificates may be requested but do not substitute for the technical plans. The plans are the core submittal for plan review.

Question 20Knowledge of applicable codes and ordinances

A PV array is installed on a roof in a high-wind region. Which code document governs the structural wind loading requirements for the array mounting?

  1. The International Building Code or International Residential Code as adopted locally Correct answer.
  2. The utility interconnection tariff
  3. The National Electrical Code only
  4. The module datasheet only

Explanation

Structural wind loading for roof-mounted arrays is governed by the building code adopted in the jurisdiction, such as the IBC or IRC, often with ASCE 7 referenced. The NEC addresses electrical safety, not structural loading. Tariffs and datasheets do not establish structural design requirements.

Question 21Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling. Which requirement applies to the grounding of the PV module frames and mounting structure?

  1. Module frames must be isolated from the equipment grounding conductor
  2. Module frames must be connected to the grounded conductor
  3. Module frames may be left ungrounded if the array is below 50 V
  4. Exposed non-current-carrying metal parts must be connected to the equipment grounding conductor Correct answer.

Explanation

Exposed non-current-carrying metal parts of PV modules and mounting structures must be bonded to the equipment grounding conductor to clear faults and protect people. Connecting frames to the grounded conductor would create a parallel path and is not permitted. Isolation from the equipment grounding conductor defeats the safety function.

Question 22Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that has adopted the 2023 NEC. Which requirement applies to the labeling of a PV system disconnect that is not the service disconnect?

  1. It must be marked with the module tilt angle
  2. It must be marked with the installer's phone number
  3. It must be marked with the utility account number
  4. It must be marked to indicate that it is a PV system disconnect and that the terminals may be energized in the open position Correct answer.

Explanation

PV disconnects must be marked to warn that the line and load terminals may remain energized when the device is open, because the PV source cannot be de-energized by opening the disconnect. This warning protects service personnel. Account number, tilt angle, and phone number are not the required warning content.

Question 23Knowledge of applicable codes and ordinances

A PV array is installed on a roof with a ridge. Which requirement applies to the access pathway along the ridge for firefighters?

  1. A clear pathway must be maintained along the ridge as specified by the adopted fire code Correct answer.
  2. No pathway is required if the array is flush-mounted
  3. A pathway is required only on commercial buildings
  4. A pathway is required only if the array exceeds 100 kW

Explanation

The adopted fire code, often the International Fire Code, specifies required access pathways along ridges and at edges of roofs with PV arrays so firefighters can ventilate and move safely. These requirements apply to residential as well as commercial roofs and are not based on system size alone. Flush mounting does not eliminate the pathway requirement.

Question 24Knowledge of applicable codes and ordinances

A PV system uses a central inverter with a 600 V DC input. Which requirement applies to the DC conductors between the array and the inverter when they run through a building?

  1. They may be run through a plenum without conduit
  2. They may be run as exposed single conductors without support
  3. They may be spliced with wire nuts inside a wall cavity
  4. They must be installed in a raceway or otherwise protected as required by the wiring method Correct answer.

Explanation

DC conductors run through a building must use an approved wiring method, typically a raceway or cable assembly, with proper support and protection. Exposed unsupported conductors, plenum runs without approved methods, and inaccessible splices inside wall cavities violate the wiring method requirements. The method must also suit the location.

Question 25Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling in a jurisdiction that requires a utility interconnection application. Which document typically must be submitted to the utility before energizing the system?

  1. An interconnection application with the system ratings and a signed agreement Correct answer.
  2. A copy of the homeowner's deed only
  3. A copy of the module warranty only
  4. A copy of the installer's insurance certificate only

Explanation

Utilities require an interconnection application that documents system ratings and a signed interconnection agreement before the system may be energized in parallel. Warranties, insurance certificates, and deeds may be requested for other purposes but do not fulfill the interconnection application requirement. Approval from the utility is a precondition to parallel operation.

Question 26Knowledge of applicable codes and ordinances

Under the NEC, which document is the primary source for the requirements covering the installation of a PV power system, including disconnects, grounding, and marking?

  1. Article 480
  2. Article 705
  3. Article 690 Correct answer.
  4. Article 250

Explanation

Article 690 of the NEC specifically governs solar photovoltaic systems and contains the rules for circuit sizing, disconnects, grounding, and labeling. Other articles apply only by cross-reference or to related systems.

Question 27Knowledge of applicable codes and ordinances

A PV system is being installed in a state that has adopted a newer edition of the NEC than the local city code. Which code edition typically governs permit review for the installation?

  1. The edition adopted by the authority having jurisdiction with legal authority over the project Correct answer.
  2. The edition in effect when the PV equipment was manufactured
  3. The edition referenced in the module manufacturer's installation manual
  4. The most recent NEC edition published nationally, regardless of local adoption

Explanation

The authority having jurisdiction adopts a specific code edition, and that edition is what inspectors enforce. National publication of a newer edition does not make it law locally until adopted.

Question 28Knowledge of applicable codes and ordinances

A designer is checking whether a rooftop PV array complies with fire access provisions. Which code contains the requirement for pathways along ridges and eaves on residential roofs?

  1. The International Energy Conservation Code
  2. NFPA 70E
  3. The International Fire Code as adopted locally Correct answer.
  4. The National Electrical Safety Code

Explanation

Fire access and setback provisions for rooftop PV arrays come from the International Fire Code, which many jurisdictions adopt and enforce alongside the NEC. The NEC addresses electrical safety, not firefighter access pathways.

Question 29Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling. Which marking is required at the point where the PV system is interconnected to the building's electrical system?

  1. A warning label listing the module model numbers only
  2. A placard showing the system's annual energy production estimate
  3. A permanent plaque or directory indicating the location of the PV system disconnect and the power source Correct answer.
  4. A temporary tag identifying the installing contractor

Explanation

The NEC requires a permanent plaque or directory at the service equipment or another approved location that identifies the PV power source and the location of its disconnecting means. This informs responders and service personnel of energized conductors.

Question 30Knowledge of applicable codes and ordinances

A PV array is installed on a roof in a high-wind region. Which code document governs the structural wind-loading requirements for the mounting system?

  1. Article 690 of the NEC
  2. The International Building Code or International Residential Code as adopted locally Correct answer.
  3. The National Electrical Safety Code
  4. NFPA 70E

Explanation

Structural wind loading on roof-mounted PV support systems is governed by the building code adopted in the jurisdiction, typically the IBC or IRC. The NEC covers electrical requirements and defers structural matters to the building code.

Question 31Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that requires a building permit. Which document is typically submitted to show the array layout, equipment locations, and one-line electrical diagram?

  1. A permit application package with plan drawings and specifications Correct answer.
  2. The utility's rate schedule
  3. The module warranty certificate
  4. The installer's business license only

Explanation

Permit review requires construction documents that show the array layout, equipment locations, and electrical single-line details so the AHJ can verify code compliance. Warranty and rate documents do not demonstrate code compliance.

Question 32Knowledge of applicable codes and ordinances

A PV array is installed on a dwelling. Which requirement applies to the grounding of module frames and the mounting structure?

  1. Module frames may be left ungrounded if the array is below 30 V
  2. Grounding is required only when the inverter is transformerless
  3. Only the array rails require bonding, not the modules
  4. Exposed non-current-carrying metal parts must be connected to the equipment grounding conductor Correct answer.

Explanation

The NEC requires exposed non-current-carrying metal parts of PV systems, including module frames and mounting structures, to be bonded to the equipment grounding conductor. Listed bonding hardware and methods must be used.

Question 33Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that requires a utility interconnection application. Which document is typically required by the utility before the system may be energized?

  1. The module datasheet only
  2. The installer's insurance certificate only
  3. The building permit receipt only
  4. An approved interconnection agreement and a signed net-metering or interconnection application Correct answer.

Explanation

Utilities require an approved interconnection application and agreement before authorizing parallel operation. The building permit alone does not authorize interconnection to the grid.

Question 34Knowledge of applicable codes and ordinances

A PV system is interconnected to the load side of the service disconnect in a dwelling. Which NEC article governs the interconnection of power production sources with the building's electrical system?

  1. Article 250
  2. Article 690
  3. Article 230
  4. Article 705 Correct answer.

Explanation

Article 705 provides the requirements for interconnecting power production sources, including PV, with other electrical power sources and the utility. Article 690 covers the PV system itself and is used together with Article 705 at the point of interconnection.

Question 35Knowledge of applicable codes and ordinances

A PV array is installed on a roof with a ridge. Which requirement applies to the access pathway along the ridge for firefighter use?

  1. A pathway is required only on roofs steeper than 12 inches per foot
  2. The pathway width is set by the NEC based on array voltage
  3. A clear pathway of the width required by the adopted fire code must be maintained along the ridge Correct answer.
  4. No pathway is required if the array is flush-mounted

Explanation

The adopted fire code establishes required access pathways, including ridge pathways, so firefighters can traverse the roof. The NEC does not set these pathway dimensions.

Question 36Knowledge of applicable codes and ordinances

A PV system uses a central inverter with a 600 V DC input. Which requirement applies to the DC conductors between the array and the inverter?

  1. Conductors may be sized at 100 percent of the continuous current
  2. Conductors must be sized for at least 125 percent of the continuous current and protected per Article 690 Correct answer.
  3. Conductors must be sized at 80 percent of the continuous current
  4. Conductor sizing is determined solely by the inverter's AC output rating

Explanation

Article 690 requires PV source and output circuit conductors to be sized at not less than 125 percent of the continuous current, with overcurrent protection as applicable. The 125 percent factor accounts for continuous operation and conductor ampacity derating.

Question 37Knowledge of applicable codes and ordinances

A PV module has a rated open-circuit voltage of 45.0 V and a temperature coefficient of -0.30 percent per degree Celsius. At a record low ambient temperature of -10 degrees Celsius, which correction should be applied to determine maximum system voltage?

  1. Increase the open-circuit voltage because the coefficient is negative and temperature is below 25 degrees Celsius Correct answer.
  2. Decrease the open-circuit voltage because the temperature is below 25 degrees Celsius
  3. Apply no correction because the coefficient is negative
  4. Apply the coefficient only to the short-circuit current

Explanation

A negative voltage temperature coefficient means open-circuit voltage rises as cell temperature falls below 25 degrees Celsius. The maximum system voltage must be calculated using the coldest expected temperature to ensure the inverter's voltage limit is not exceeded.

Question 38Knowledge of applicable codes and ordinances

A PV system is installed on a commercial building with a flat roof. Which requirement applies to the marking of the DC conductors and disconnects?

  1. Markings must identify the conductors and equipment as part of a PV power source and indicate the location of the disconnecting means Correct answer.
  2. Markings are required only if the system exceeds 1000 V
  3. Markings may be omitted if the system is not accessible to the public
  4. Markings are required only on the inverter

Explanation

Article 690 requires labeling that identifies PV system conductors and equipment and directs personnel to the disconnecting means. These markings are required regardless of building occupancy or system voltage class.

Question 39Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that has adopted the 2020 NEC. Which article would an installer consult for the general requirements for PV systems, including rapid shutdown?

  1. Article 250
  2. Article 690 Correct answer.
  3. Article 230
  4. Article 705

Explanation

Article 690 contains the PV system requirements, including rapid shutdown provisions introduced in recent editions. Article 705 covers interconnection, while Articles 250 and 230 cover grounding and services.

Question 40Knowledge of applicable codes and ordinances

A PV system is installed on a commercial building. Which requirement applies to rapid shutdown of PV system conductors?

  1. Rapid shutdown requires complete physical removal of the array
  2. Conductors within the array boundary must be controlled to a specified voltage limit upon rapid shutdown initiation Correct answer.
  3. Rapid shutdown applies only to residential systems
  4. Rapid shutdown is satisfied by opening the inverter AC disconnect only

Explanation

The NEC rapid shutdown provisions require that, upon initiation, controlled conductors within the array boundary be reduced to a specified voltage limit. The requirement applies to systems covered by Article 690, not only dwellings.

Question 41Knowledge of applicable codes and ordinances

A PV array is mounted on a roof with a slope of 4 inches per foot. Which requirement applies to the clearance between the array and the roof surface?

  1. The array must be mounted flush with no clearance
  2. The array must be installed to allow access and ventilation as required by the code and manufacturer instructions Correct answer.
  3. Clearance is required only on flat roofs
  4. The array must have at least 12 inches of clearance regardless of slope

Explanation

The NEC and manufacturer instructions require roof-mounted arrays to be installed so that wiring and equipment remain accessible and ventilation is provided as specified. The specific clearance depends on the mounting method and slope.

Question 42Knowledge of applicable codes and ordinances

A residential PV system uses a string inverter with a DC disconnect mounted next to the inverter. Which requirement applies to the DC disconnect location?

  1. It must be readily accessible and located within sight of the inverter Correct answer.
  2. It may be installed in a locked utility room inaccessible to the homeowner
  3. It may be omitted if the inverter has an integral DC switch
  4. It must be installed on the roof next to the array

Explanation

The NEC requires the PV disconnecting means to be readily accessible and located within sight of the equipment it disconnects. This allows service personnel to isolate the DC circuits safely.

Question 43Knowledge of applicable codes and ordinances

A PV system is installed in a jurisdiction that has adopted the 2023 NEC. Which requirement applies to the labeling of a rapid shutdown system?

  1. A permanent label must identify the rapid shutdown equipment and its initiation method Correct answer.
  2. Labels are required only for systems above 1000 V
  3. Labels are required only on the inverter
  4. Labels are optional if the homeowner is trained

Explanation

The NEC requires permanent labeling that identifies rapid shutdown equipment and describes how to initiate the function so responders and service personnel can operate it. The requirement is not limited to high-voltage systems or optional training.

Question 44Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling with a 200 A service panel and a 200 A busbar. The main breaker is 200 A. A load-side PV interconnection is proposed. Which rule governs the maximum permitted sum of the main breaker and the PV breaker?

  1. The sum may not exceed 120 percent of the busbar rating unless the panel is listed for a higher sum Correct answer.
  2. The sum is unlimited if the PV breaker is backfed
  3. The sum may not exceed 100 percent of the busbar rating in all cases
  4. The sum may not exceed 80 percent of the busbar rating

Explanation

The NEC allows the sum of the main overcurrent device and the PV source overcurrent device to reach 120 percent of the busbar rating, with higher sums permitted only where the panel is listed for them. This is the common 120 percent busbar rule for load-side interconnections.

Question 45Knowledge of applicable codes and ordinances

A PV source circuit is installed on a rooftop in an exposed location subject to sunlight. Which requirement applies to the conductor insulation and wiring method?

  1. Conductors must be listed for sunlight exposure or protected by a raceway or suitable covering Correct answer.
  2. Conductors must be installed in rigid metal conduit only
  3. Any conductor type may be used because the circuit is DC
  4. The conductor ampacity may be ignored because the circuit is current-limited

Explanation

Exposed PV conductors subject to sunlight must use a wiring method or conductor insulation rated for sunlight exposure, or be protected by a raceway. This prevents insulation degradation from ultraviolet radiation.

Question 46Knowledge of applicable codes and ordinances

A PV system is being designed for a jurisdiction that requires compliance with the adopted electrical code and the adopted building code. Which statement best describes how these codes interact for a roof-mounted array?

  1. The electrical code governs circuits and disconnects, while the building code governs structural loading and fire access Correct answer.
  2. The electrical code governs all structural and fire access requirements
  3. The building code supersedes the electrical code for conductor sizing
  4. Only the utility interconnection rules apply to roof-mounted arrays

Explanation

The electrical code addresses circuits, grounding, disconnects, and marking, while the building and fire codes address structural loading and firefighter access. A compliant design must satisfy both sets of adopted requirements.

Question 47Knowledge of applicable codes and ordinances

A designer is evaluating whether a PV array can be installed over a roof area that serves as a required fire access pathway. Which principle applies?

  1. The array may cover the pathway if the homeowner signs a waiver
  2. The array may cover the pathway if the system is under 10 kW
  3. The array may cover the pathway if the modules are listed for fire resistance
  4. The array must preserve the access pathway dimensions required by the adopted fire code or be redesigned Correct answer.

Explanation

Fire code access pathways must remain clear to allow firefighter operations. An array layout that obstructs required pathways must be revised to preserve the required dimensions; listings and waivers do not override the fire code.

Question 48Knowledge of applicable codes and ordinances

A PV system is installed on a dwelling in a jurisdiction that has adopted the NEC. Which statement correctly describes how the NEC and local amendments apply?

  1. Local amendments adopted by the AHJ apply in addition to or in place of NEC provisions where legally adopted Correct answer.
  2. The NEC applies only after the utility approves interconnection
  3. The NEC always supersedes local amendments
  4. Local amendments apply only to commercial systems

Explanation

Local jurisdictions may adopt amendments to the NEC, and those amendments are enforceable where legally adopted. The NEC applies as the base code, modified by any valid local amendments.

Question 49Knowledge of applicable codes and ordinances

A PV system uses a central inverter and a DC combiner. An installer is determining the required disconnect configuration. Which statement best reflects the NEC requirement for the PV disconnecting means?

  1. A disconnecting means must be provided for the PV source and output circuits and be readily accessible and within sight of the equipment Correct answer.
  2. A single disconnect on the AC side satisfies all DC disconnect requirements
  3. No disconnect is required if the inverter has a built-in switch
  4. Disconnects are required only on systems above 1000 V

Explanation

The NEC requires disconnecting means for PV source and output circuits, located so they are readily accessible and within sight of the equipment they control. An AC disconnect alone does not satisfy DC disconnect requirements.

Question 50Knowledge of applicable codes and ordinances

A PV system is installed on a building where the AHJ requires plan review. Which combination of documents most completely supports code compliance review for the electrical and structural aspects?

  1. Electrical single-line diagram, array layout with setbacks, and structural calculations for the mounting system Correct answer.
  2. Module warranty and a homeowner affidavit
  3. Module datasheets and a utility bill
  4. Installer license and proof of insurance

Explanation

Plan review for a PV system requires electrical design documents, array layout showing fire access setbacks, and structural calculations for the mounting system. Together these demonstrate compliance with both the electrical and building codes.