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WorksheetsNABCEP PVA Practice Exam Mash Up #5
Total questions: 70
Worksheet time: 35mins
You find a dc disconnect with an open door. You should assume:
Since you cannot open the door without the disconnect being off, then the disconnect is safe to work on.
That the disconnect is being worked on by another electrician.
That all conductors and terminals in the disconnect are energized.
That line and load are only energized in the open position.
When calculating energy, which units should you use for the current in your equation?
A for Amperes
I for current
C for current
F for flow
What is an example of a direct coupled PV system?
A PV system with a battery and no charge controller with the load designed, so that it does not overcharge the battery.
A PV system that is directly connected to the utility
PV and a load with no energy storage or utility connection
Every water pumping PV system is direct coupled
When the sun is shining on the PV arrays, under normal circumstances and for best production, the best thing to do is:
Open the disconnects
Short the conductors
Replace fuses
Close the disconnects
What limits the maximum power rating of the largest load of an off-grid system?
the size of the battery
the size of the array
the size of the inverter plus any other power source
the size of the charge controller
What is an NRTL?
Nationally Recognized Testing Labs
National Renewable Testing Lab
A federal government agency that oversees renewable energy incentives on a state level.
A federal government agency that oversees tariffs on renewable energy equipment.
Which of the following is the worst design flaw when an inexperienced person designs a PV system?
Multiple orientations within a PV source circuit
Multiple orientations for different PV source circuits
Occasional shading on a module that is in a PV source circuit that has its own MPP
Microinverters used on a commercial job
What contributes to determining the ampacity or the temperature rating of a conductor?
Insulation
Insolation
Fill factor
Sealing raceways
A 16A interactive inverter that operates at a 240V utility nominal voltage will produce how much power when clipping?
38kW
3840W
15kW
0.038MW
According to Ohm's law and voltage drop, what is the relationship between voltage drop and current?
Proportional
Inversely proportional
Directly inverse
Inversely direct
Which addresses environmental hazards on a safety plan?
SDS
Fall protection
Ladder safety
Nearest hospital address
What is the solar window?
A place where the sun can be throughout the year, often defined as between 9am and 3pm.
A transparent device used to determine sun paths
The location in the sky where the sun will never be, such as north
A window that faces south in the northern hemisphere or a window that faces north in the southern hemisphere.
Which of the following will have the highest voltage setting for charging flooded lead-acid batteries?
Bulk charge
Absorption charge
Float charge
Equalization charge
Which of these would you be most likely to find on a module spec sheet?
Temperature coefficient
Maximum string size
Output frequency
Voltage drop from module to inverter
When working on a lead-acid battery bank with a hydrometer, what is the most important personal protective equipment?
Fall protection
Apron
Eye protection
Equalizer
5) What is the operating range of the array at Standard Test Conditions?
There are 4 PV source circuits of 10 modules each.
Given: Module information: Power = 250W, Open Circuit Voltage = 40V, Maximum
Power Voltage = 35V, Short Circuit Current = 8A, Maximum Power Current =
7.14A, Temp Coefficient for Voltage −0.33%/°C, CEC Power 220W, NOCT 48°C
Inverter information: Low MPPT voltage 230V, Inverter maximum input voltage
550V.
160V
350V
140V
230V
What is the most typical hazard with PV systems of the following?
Shock
Arc Flash
Lighting
Earthquake
Which is the smallest installable part of a PV system?
Solar Panel
Solar Module
Solar Array
PV Source Circuit
Current is affected mostly by
The number of solar cells in series
The size of the solar cell
The backsheet of the solar module
The temperature of the cell
What information is needed in order to perform inter-row spacing calculations?
Solar constant and current
Solar zenith angle and power of modules
Shading derating factor and azimuth
Solar elevation angle and solar azimuth angle
A PV array at a higher elevation would tend to produce more
Current
Heat
Resistance
Polysilicon
Transformers convert
High voltage low current to low voltage low current
Low voltage low current to high voltage high current
High voltage low current to low voltage high current
Low current low current to high voltage low current
The primary power source for a utility interactive PV system is the
Inverter
Utility
PV
Charge controller
Electrical safety is best studied at
OSHA website
OSH website
CSLB website
UL website
What is the UL listing for PV that can be used in the US?
UL 2703
UL 1741 or UL 1741-SA
UL 3741 or UL 1741
UL 61730 or UL 1703
Sun path charts differ based on
Longitude
Latitude
Azimuth
Tilt angle
What is the main use of PV wire?
Intermodule connections
Inverter ac connections
Must be used on grounded systems
PV output circuits
Which types of wires can be used for connecting modules beneath arrays with exposed conductors?
THWN-2 and THHN
XRS and FTP
PV wire and USE-2
NMC and RTTW
A 16A interactive inverter output circuit will require a circuit breaker of how many amps?
16A
20A
Less than 16A
30A
Of the following, which is the most subject to damage during an installation?
The frames due to bending
The glass due to corrosion
The backsheet due to contact with sharp edges and module corners
The conductors due to water damage
What instrument can best test the insulation resistance of a conductor?
Insulometer
Megohmmeter
Digital multimeter
Caloric wire tester
What type of PV racking system is often seen on a commercial low-slope roof without any penetrations and with concrete pavers or blocks to keep it from blowing away?
Ballasted
Aerodynamic
Hyperstantioned
Epoxy stationed
A 100-seat café has 3kW of PV modules and 12kWh of energy storage. What would be the best use case?
Power saving and significant peak load reduction
Ability to operate the restaurant for days
Ability to run electronic devices for hours
Running air conditioner
How do you get a reading with a low current source and a clamp on ammeter?
Turn the clamp in the other direction
Press the probes harder against the terminals
Turn the backlight off on your meter
Loop the wire around and divide by the number of loops
What is the least amount of current that would contract someone’s muscle, and someone would not be able to let go?
1A - 5A
3A - 10A
10 to 20mA
0.5A - 1A
What are the units that you measure apparent power?
kW
VAR
Ohms
VA
Who approves the interconnection of a PV system?
Local contractor board
State Public Utility Commission (PUC)
Utility
Authority Having Jurisprudence
If magnetic declination is 5 degrees east, then where is true south?
Where the compass reads 0 degrees
Where the compass reads 180 degrees
Where the compass reads 185 degrees
Where the compass reads 175 degrees
If someone had a snow lodge with a wall facing south, what would be the best argument for increasing tilt to very steep or even vertical on the wall?
To decrease reflection from solar modules onto people walking towards the lodge
To increase production from reflection off the snow
To prevent heat buildup underneath the modules
To increase summer production for net-metering situations
In the western part of the USA and Canada, what direction does the north arrow of a magnetic compass point?
South of west
West of north
East of north
West of east
When handling PV modules on a roof in sunlight, what is the most common method of safety of the following?
Take all connectors off the modules
Test voltage every 5 minutes
Make sure that connectors are open
Keep tape over the glass and around the corners of the frames
Which room cannot have a PV dc disconnect?
Kitchen
Attic
Bathroom
Bedroom
A system that sits on a flat/low-slope rooftop and has no penetrations is called a
Flush mounted system
Flashed system
BIPV system
Ballasted system
Which is the worst design error?
BIPV on a commercial job
A fast-growing tree to the north of the array in Idaho
PV at 5-degree tilt at 40 degrees latitude
Different tilt angles in a PV source circuit
A stand-alone PV system will work in this mode:
Island
Anti-island
Interactive
Multimode
Which building codes will be used in residential construction and adopted much like the NEC?
International Building Code
International Residential Code
American Building Code
US Residential Code
Which of the following types of safety equipment will prevent a fall from a roof?
Fall arrest
Fall restraint
Fall system
Fall resistor
Which of these are required parts of a personal fall arrest system?
Lifeline, connector, eyewash, body harness
Positioning device, rope, warning line
Anchorage, lifeline, connector, body harness
Deceleration device, connector, body belt
An agreement in which a third party developer installs, owns, and operates a PV system on a customer’s property and the customer purchases the energy produced by the system at an agreed upon rate which is generally lower than the rate of the utility.
Solar Lease
Power Purchase Agreement
Power Production Agreement
Estimated Power Agreement
Name for the type of monetary charge from the utility for the most power a customer has used in a 15-minute interval for that billing period.
Interval charge
Delivery charge
Demand charge
Peak power fee
What is the ground mount advantage over a rooftop system?
Takes no extra real estate
Cooler
Increased photosynthesis
Soiling
What is the intermediary between the manufacturer and the integrator?
Engineer
Distributor
Designer
AHJ
Which of the following is a typical direct PV system application?
Lighting
Batteries
Pumping water
Fire alarm
If the inverter voltage is 240V (residential US inverter voltage) and the power is
4000W, then what is the smallest size circuit breaker you could use?
15A
20A
25A
30A
What are the units for reactive power?
VA
Reactance
VAr
Ohms
At what rate does the sun move in relationship to Earth (from the perspective of
someone being on Earth)?
10 degrees per minute
15 degrees per hour
12 degrees per arc second
36 degrees per hour
Which of these would cause an interactive inverter to turn off for safety?
Grid is out
Clouds
Warm temperature
Higher PV to inverter ratio
Maintenance of sealed valve regulated lead-acid batteries includes
Checking fluid levels
Equalization charge
Scrubbing lead plates
Cleaning terminals
A remote cabin uses the loads below per day, how much total energy is used per day? • 1000W toaster for 6 minutes • 1.2kW hot water heating element for 3 hours per day • Three 17W LED lights for 3 hours per day • iPhone 100 charger at 20W for 3 hours per day
0.13cWh
39kWh
3.9kWh
3900mWh
If your dc stand-alone PV array supplies 4kWh per average day from the PV in a location with an average of 5 peak-sun-hours (PSH) per day with a battery round trip efficiency of 70%, and the entire system voltage is 24V including loads. What would be the resistance of the loads if the loads were on constantly with a constant power draw?
4 ohms
4R
4.9 ohms
44 VA
What is the best voltage for charging a 12V lead-acid battery?
12V
11.8V
12.3V
14.1V
An Array in Sacramento California in August (hot and dry) is not producing as
expected. Which of the following is NOT a likely problem?
Decreased ac wire size and voltage loss
String size too short
String size too long
Soiling
Units for irradiance are
Energy per area
Power per area
Volts per square meter
Amps per square meter
Stand-alone inverter output goes to
Loads
Utility
Meter
PV
Which is an NRTL?
National Renewable Testing Lab
CE
ULA
CSA
Which is a self-commutated inverter?
Thyristor operating without energy
Anti-islanding inverter
Interactive inverter
Stand-alone inverter
Why is it important to install a DCcombiner box according to manufacturer's
instructions?
Because the dc combiner only uses dc rated wire
Because the combiner box cannot be used as a junction box
Because it is listed for use this way
Because it has holes that are made for that purpose
What is the most important and safest measurement to take before disconnecting
PV Modules at the MC connector?
Voltage
Power
Energy
Current
If installing a stand-alone 120V inverter using 120/240V distribution equipment what
type of labelling is required?
Warning that multiwire branch circuits are connected
Warning not to connect multiwire branch circuits
Warning for non-load-break rated fuses
Minimum current to start inverter
Which of these environmental factors will have the greatest effect on a ballasted
PV system on a flat roof?
Daily temperature fluctuations
Seismic loads
Hail
Walking on roof
