NABCEP PV SYSTEM INSPECTOR CERTIFICATION
During an inspection of a 90kW commercial rooftop PV system, the inspector notices
that the orientation of the PV does not match the plans. The solar installer said the
engineer told him that it would be code compliant to change the tilt or azimuth, since the
NEC does not cover PV orientation and the project will actually be safer and produce
more energy. What is the best reason that the inspector gave for a failed the inspection
- Answers - The installation does not match the permit design
When dc PV circuits are installed in conduit, it is required to have a label that says
something like: "WARNING: PHOTOVOLTAIC POWER SOURCE." What is the
MAXIMUM distance between labels? - Answers - 10'
What is the label that should be on dc-to-dc converter source circuit conduit on the side
of a building? - Answers - White letters on red background saying "WARNING:
PHOTOVOLTAIC POWER SOURCE" every 10 feet
What is a function of a diversion charge controller? - Answers - Prevents overcharging
The PV dc disconnecting means label in an interactive inverter, shall have the following
information - Answers - Maximum voltage
Battery system working space lighting controls must be controlled by - Answers - Not by
automatic means only
The diagram you are given by the building department shows that you cannot have a
rafter sag that is more than 1 inch every 25 feet. If you have a 15-foot rafter span, what
would be the maximum sag? - Answers - 0.6"
Applies to AC conductors of the same circuit, grounded conductors, and all equipment
grounding conductors and bonding conductors - Answers - Shall be contained within the
same raceway, auxiliary gutter, cable tray, cable bus assembly, trench, cable, or cord,
unless otherwise permitted.
What is the maximum roof slope for a typical south facing ballasted PV system? -
Answers - 5 degrees or less
A ground mounted PV array has 40 PV source circuits of 20 PV modules each
connected in parallel at a dc combiner in a field. Imp = 8A and Isc = 8.5A. What is the
minimum ampacity rating of the PV source circuit fuses? - Answers - 15A
At least how wide must a fire access pathway be on a residential roof? - Answers - 3
feet
, Based on an ambient temperature of 32°C, what is the ampacity of a #12-AWG, THWN-
2 copper conductor three current-carrying conductors and a ground in a raceway? -
Answers - 28.8 A
Hint: Use 310 Tables
When can you use a plug-in type breaker without a fastener for an inverter output
circuit? - Answers - When the inverter output circuit is listed as interactive
What is the limit of bends between places where wire can be pulled in an EMT or other
typical conduit run? - Answers - 360 degrees
Which type of wire can be installed under a PV array in free air? - Answers - USE-2
What is the best and most Code compliant way to insure against corrosion with
dissimilar metals, such as copper and aluminum in a solar PV array? - Answers - Using
listed products that are listed to work with the different types of metals
If you are using a UL 2703 listed racking system, in which case can you use it for
bonding modules? - Answers - The racking system has to be identified for grounding PV
modules
If cables are put through holes in studs or rafters without using steel plates, what is the
smallest distance that the drilled holes can be from the edge of the structural wood
member? - Answers - 1.25"
For an interactive inverter output circuit, which is connected to a 30A breaker, what is
the minimum size copper equipment grounding conductor (EGC) inside of conduit? -
Answers - 10AWG
-Table 250.122:
A roof mounted PV system with aluminum rails uses a bare copper equipment
grounding conductor (EGC), which is attached to the rails with cable ties. Which of the
following is most likely to be a problem? - Answers - Corrosion may be a problem
OSHA requires facilities for quick drenching of the eyes and body by a battery handling
area within: - Answers - 25'
-OSHA 1926.441(a)(6)
The IFC (International Fire Code) requires a brush free area how far from the PV array?
- Answers - 10'
Of the following, which is required for a sign disconnect for a storage battery system
over 60V in an office building? - Answers - The date of a calculation
-Storage Batteries is Article 480.7(F)
During an inspection of a 90kW commercial rooftop PV system, the inspector notices
that the orientation of the PV does not match the plans. The solar installer said the
engineer told him that it would be code compliant to change the tilt or azimuth, since the
NEC does not cover PV orientation and the project will actually be safer and produce
more energy. What is the best reason that the inspector gave for a failed the inspection
- Answers - The installation does not match the permit design
When dc PV circuits are installed in conduit, it is required to have a label that says
something like: "WARNING: PHOTOVOLTAIC POWER SOURCE." What is the
MAXIMUM distance between labels? - Answers - 10'
What is the label that should be on dc-to-dc converter source circuit conduit on the side
of a building? - Answers - White letters on red background saying "WARNING:
PHOTOVOLTAIC POWER SOURCE" every 10 feet
What is a function of a diversion charge controller? - Answers - Prevents overcharging
The PV dc disconnecting means label in an interactive inverter, shall have the following
information - Answers - Maximum voltage
Battery system working space lighting controls must be controlled by - Answers - Not by
automatic means only
The diagram you are given by the building department shows that you cannot have a
rafter sag that is more than 1 inch every 25 feet. If you have a 15-foot rafter span, what
would be the maximum sag? - Answers - 0.6"
Applies to AC conductors of the same circuit, grounded conductors, and all equipment
grounding conductors and bonding conductors - Answers - Shall be contained within the
same raceway, auxiliary gutter, cable tray, cable bus assembly, trench, cable, or cord,
unless otherwise permitted.
What is the maximum roof slope for a typical south facing ballasted PV system? -
Answers - 5 degrees or less
A ground mounted PV array has 40 PV source circuits of 20 PV modules each
connected in parallel at a dc combiner in a field. Imp = 8A and Isc = 8.5A. What is the
minimum ampacity rating of the PV source circuit fuses? - Answers - 15A
At least how wide must a fire access pathway be on a residential roof? - Answers - 3
feet
, Based on an ambient temperature of 32°C, what is the ampacity of a #12-AWG, THWN-
2 copper conductor three current-carrying conductors and a ground in a raceway? -
Answers - 28.8 A
Hint: Use 310 Tables
When can you use a plug-in type breaker without a fastener for an inverter output
circuit? - Answers - When the inverter output circuit is listed as interactive
What is the limit of bends between places where wire can be pulled in an EMT or other
typical conduit run? - Answers - 360 degrees
Which type of wire can be installed under a PV array in free air? - Answers - USE-2
What is the best and most Code compliant way to insure against corrosion with
dissimilar metals, such as copper and aluminum in a solar PV array? - Answers - Using
listed products that are listed to work with the different types of metals
If you are using a UL 2703 listed racking system, in which case can you use it for
bonding modules? - Answers - The racking system has to be identified for grounding PV
modules
If cables are put through holes in studs or rafters without using steel plates, what is the
smallest distance that the drilled holes can be from the edge of the structural wood
member? - Answers - 1.25"
For an interactive inverter output circuit, which is connected to a 30A breaker, what is
the minimum size copper equipment grounding conductor (EGC) inside of conduit? -
Answers - 10AWG
-Table 250.122:
A roof mounted PV system with aluminum rails uses a bare copper equipment
grounding conductor (EGC), which is attached to the rails with cable ties. Which of the
following is most likely to be a problem? - Answers - Corrosion may be a problem
OSHA requires facilities for quick drenching of the eyes and body by a battery handling
area within: - Answers - 25'
-OSHA 1926.441(a)(6)
The IFC (International Fire Code) requires a brush free area how far from the PV array?
- Answers - 10'
Of the following, which is required for a sign disconnect for a storage battery system
over 60V in an office building? - Answers - The date of a calculation
-Storage Batteries is Article 480.7(F)
