NABCEP PV INSTALLATION PROFESSIONAL
EXAM 2024-2025
NABCEP
North American Board of Certified Energy Practioners
JTA
Job Task Analysis
The JTA outlines the expected duties of a qualified PV installation
professional.
Brainpower
Read More
Conduit Fill
(i.e. Maximum Percent of Conduit Area Available for Conductors)
NEC Chapter 9 Table 1
Voltage Drop Limits
ASHRAE 90.1 Standards suggests no more than 3% of nominal
voltage.
NEC suggests no more than 5% in an "Informational Note".
Sunpower standard is no more than 1%.
Voltage Drop Equation
% drop =(0.2 x D x I x R )/V
,Where:
D= one-way distance (in feet)
I = current (nominal actual value, no 125% factors, use Imp for solar
circuits)
R = resistance of conductors (in ohms/1000ft)
V = voltage (typical, nominal, use Vmp for solar circuits)
Resistance values can be found in NEC Chapter 9 Table 8
"Conductor Properties"
What size FMC conduit should be used for four size 6 AWG XHHW
conductors, one size 8 AWG XHHW EGC and four 10 AWG THHN
conductors? Only use the NEC code book to answer this question.
1-1/4"
Use Chapter 9 Tables 4 and 5.
BIPV
Building-Integrated Photovoltaics
Can single phase inverters be connected to 3-phase power systems?
Yes, as long as significant unbalanced voltages cannot result
705.100
What is the minimum busbar rating for a subpanel used as an inverter
ac combiner panel to combine three 4000W, 240V single phase
inverters?
125A
Rating of each breaker = 16.7 X 1.25 = 25A
Sum of inverter breakers = 3 x 25A = 75A
Minimum size of back-fed breaker in main service panel = 3 x 16.7A x
1.25 = 62.2 --> 70A
,Minimum size busbars in subpanel x 1.2 = inverter breakers + utility
breaker = 75A + 70A
Minimum size busbars in subpanel = (75A + 70A)/1.2 = 121 --> 125A
705.12(D)(2)
Can an inverter output be connected to a subpanel instead of the
main distribution panel?
Yes, see 705.12(D).
But be careful that each panel in series meets the minimum busbar
size requirements.
Grounded conductor
A current carrying conductor that is intentionally bonded to ground.
It is the neutral conductor in any AC system.
Equipment grounding conductor (EGC)
The green or bare copper conductor linking exposed
non-current-carrying metal parts of module frames, equipment and
enclosures
Grounding electrode conductor (GEC)
The bare copper conductor connecting the system grounding bus to
a ground rod or to the earth.
Grounding electrode
The rod or other buried electrode in the earth.
Grounding electrode system
Several grounding electrodes effectively bonded together.
Sizing EGC
The EGC should never be smaller than 14 AWG. Size the EGC
according to Table 250.122
, BOS
Balance-of-System Components include all mechanical or electrical
components and hardware used to assemble and intergrate major
components in a PV system together (i.e. all components in a PV
system except modules and inverters)
Stand-alone PV systems
PV systems that operate independently of other electrical systems.
Interactive PV systems
PV systems that operate in parallel with the electric utility grid.
Solar azimuth
The direction of the sun's horizontal projection relative to a point on
earth.
Solar altitude
The sun's elevation above the horizon.
Sun path
A graphical representation of the sun's altitude and azimuth angles
over a given day of the year.
Solar noon
The local time when the sun is at its highest point in the sky and
crossing the local meridian (line of longitude).
Solar window
The range of sun paths for a specific latitude between the winter and
summer solstices
Solar declination
The ever changing angle between the earth's equatorial plane and
the sun's rays.
EXAM 2024-2025
NABCEP
North American Board of Certified Energy Practioners
JTA
Job Task Analysis
The JTA outlines the expected duties of a qualified PV installation
professional.
Brainpower
Read More
Conduit Fill
(i.e. Maximum Percent of Conduit Area Available for Conductors)
NEC Chapter 9 Table 1
Voltage Drop Limits
ASHRAE 90.1 Standards suggests no more than 3% of nominal
voltage.
NEC suggests no more than 5% in an "Informational Note".
Sunpower standard is no more than 1%.
Voltage Drop Equation
% drop =(0.2 x D x I x R )/V
,Where:
D= one-way distance (in feet)
I = current (nominal actual value, no 125% factors, use Imp for solar
circuits)
R = resistance of conductors (in ohms/1000ft)
V = voltage (typical, nominal, use Vmp for solar circuits)
Resistance values can be found in NEC Chapter 9 Table 8
"Conductor Properties"
What size FMC conduit should be used for four size 6 AWG XHHW
conductors, one size 8 AWG XHHW EGC and four 10 AWG THHN
conductors? Only use the NEC code book to answer this question.
1-1/4"
Use Chapter 9 Tables 4 and 5.
BIPV
Building-Integrated Photovoltaics
Can single phase inverters be connected to 3-phase power systems?
Yes, as long as significant unbalanced voltages cannot result
705.100
What is the minimum busbar rating for a subpanel used as an inverter
ac combiner panel to combine three 4000W, 240V single phase
inverters?
125A
Rating of each breaker = 16.7 X 1.25 = 25A
Sum of inverter breakers = 3 x 25A = 75A
Minimum size of back-fed breaker in main service panel = 3 x 16.7A x
1.25 = 62.2 --> 70A
,Minimum size busbars in subpanel x 1.2 = inverter breakers + utility
breaker = 75A + 70A
Minimum size busbars in subpanel = (75A + 70A)/1.2 = 121 --> 125A
705.12(D)(2)
Can an inverter output be connected to a subpanel instead of the
main distribution panel?
Yes, see 705.12(D).
But be careful that each panel in series meets the minimum busbar
size requirements.
Grounded conductor
A current carrying conductor that is intentionally bonded to ground.
It is the neutral conductor in any AC system.
Equipment grounding conductor (EGC)
The green or bare copper conductor linking exposed
non-current-carrying metal parts of module frames, equipment and
enclosures
Grounding electrode conductor (GEC)
The bare copper conductor connecting the system grounding bus to
a ground rod or to the earth.
Grounding electrode
The rod or other buried electrode in the earth.
Grounding electrode system
Several grounding electrodes effectively bonded together.
Sizing EGC
The EGC should never be smaller than 14 AWG. Size the EGC
according to Table 250.122
, BOS
Balance-of-System Components include all mechanical or electrical
components and hardware used to assemble and intergrate major
components in a PV system together (i.e. all components in a PV
system except modules and inverters)
Stand-alone PV systems
PV systems that operate independently of other electrical systems.
Interactive PV systems
PV systems that operate in parallel with the electric utility grid.
Solar azimuth
The direction of the sun's horizontal projection relative to a point on
earth.
Solar altitude
The sun's elevation above the horizon.
Sun path
A graphical representation of the sun's altitude and azimuth angles
over a given day of the year.
Solar noon
The local time when the sun is at its highest point in the sky and
crossing the local meridian (line of longitude).
Solar window
The range of sun paths for a specific latitude between the winter and
summer solstices
Solar declination
The ever changing angle between the earth's equatorial plane and
the sun's rays.
