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WorksheetsNABCEP PVA Practice Exam Mash Up #1
Total questions: 70
Worksheet time: 35mins
An ammeter in combination with which other kind of meter could measure power?
Ohmmeter
Voltmeter
Energy meter
Pyranometer
What is the first action to take when a ground fault is indicated by an inverter?
Diagnose and fix the ground fault
Close the dc disconnect
Open the dc disconnect
Disconnect the strings
What is the most cost effective, yet sufficient method for marking for a PV label?
Handwriting with permanent marker
Engraving on a NEMA rated disconnect
Permanent sticker
Handwriting on permanent sticker indoors only
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
Where would you find information about SRECs and other solar incentives on a state-by-state basis?
Solarabcs.org website
IREC website
NREL website
DSIRE website
What is the power of the array at STC?
There are 4 PV source circuits of 10 PV 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.
10kW
110kW
1000W
40kW
Where do PV source circuits and PV output circuits meet?
AC combiner
PV array
DC combiner
Inverter MPP inputs
If you are sizing a PV system on a building for a location with net-metering, what is the best way of the following to size the system?
a. Multiply load factor by power factor by energy usage
b. Size the system based on energy usage, budget and available space
c. Size the system based on offsetting the entire electric bill always
d. Size the system based on how much will fit on the roof
Which device is used to determine that series wiring has been done correctly?
Clamp on ammeter
Digital multimeter
Megger
Pyranometer
MPPT is for
Optimizing energy from the utility
Getting the most energy from a battery with a MPPT inverter
Optimizing power from a PV array
Tracking the sun with a 2-axis tracker
Current carrying ability of a conductor (wire) is called
Ampacity
Amps
Inductance
Insolation
Which addresses environmental hazards on a safety plan?
SDS
Fall protection
Ladder safety
Nearest hospital address
What are the typical voltages in North American homes?
110/208 Vac
277/480 Vac
100 Vac
120/240 Vac
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.
A PV system that would produce 7kWac under STC conditions, which is not clipping power, is installed in a location with an average of 6PSH (peak sun hours, aka kWh/square meter per day average) would produce how much energy in one year?
14,008 kWh
1,503 kWh
3,307 kWh
15,330 kWh
Which of the following is the simplest type of PV system?
Utility interactive
Stand-alone
Self-regulating
Direct-coupled
What is specified on a charge controller?
Irradiance limit
Insolation limit
Maximum voltage
Minimum current
Direction on a compass is
Latitude
Longitude
Meridian
Azimuth
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
You are rebuilding an old battery system for a PV museum and everything is in amps and amp hours. You are told that the system needs to have 33% more PV
production on average than what the loads require. The loads will require 20Ah per day and the insolation will be 5PSH. If the module current at STC is 8A at Imp
and 9A at Isc, how many PV source circuits would be needed to meet the minimum requirements stated here?
1
2
3
4
The longest shadow at 2PM would be on
June 1st
November 12th
February 14th
March 29th
What is the main use of PV wire?
Intermodule connections
Inverter ac connections
Must be used on grounded systems
PV output circuits
What instrument can best test the insulation resistance of a conductor?
Insulometer
Megohmmeter
Digital multimeter
Caloric wire tester
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
An arc is caused by higher
Voltage
Current
Resistance
Energy
Who approves the interconnection of a PV system?
Local contractor board
State Public Utility Commission (PUC)
Utility
Authority Having Jurisprudence
Which tilt angle from horizontal would get the best annual production from a location in Toronto at 43 degrees north?
42 degrees
58 degrees
15 degrees
20 degrees
If an inverter indicates that there has been a ground fault, what is the first thing that a O&M technician should do?
Close all the disconnects
Open all the disconnects
Turn on the system
Replace the GFDI (ground fault detection and interruption) fuse
Which room cannot have a PV dc disconnect?
Kitchen
Attic
Bathroom
Bedroom
What is a primary factor(s) in performing wire sizing calculations?
Strands and length
UL listing
Temperature and ampacity
Color and code
What would be the most practical way to add battery backup to an existing grid-tied system?
Grid defection system
Reinstalling the system
Ac-coupled
Dc-coupled
Specification found in PV module installation manual
Torque for mounting
PTC
Cleaning
Max wind speed
A PV array produces 10kWh in a day in a location with 5 peak sun hours and a nominal battery voltage of 24V. What is the minimum required wire ampacity of the following for the PV output circuit?
15A
150A
300A
400A
How long do PV module manufacturers generally warranty their modules for?
10 years for materials and 10 years for performance
25 years for materials and 25 years for performance
25 years for materials and 10 years for performance
10 years for material and 25 years for performance
How do you ensure module manufacturer warranty is not voided?
Install according to UL listing test
Follow manufacturer installation instructions
Use local jurisdiction guidance
Follow NEC recommendations
What is the most likely maintenance to have to be done within the first 5 years of a PV installation?
Replacing broken bypass diodes
Washing the dust and pollen
Replacing cracked glass on broken modules
Removing pigeon and squirrel carcasses from under the array
What is the most common maintenance of an array on a business's existing roof over the life of the system of the following
Replacing MC connectors of PV modules
Replacing bypass diodes
Removal of system for re-roof of building
Washing snail trails off of PV modules
There is a system with 4 concrete pavers (weights) securing it on a rooftop. What kind of system is this?
Ballast rack mount
Ballast standoff
East-west tilt mount
Single axis-tracker
In the image below of an IV curve, which point mostly represents the MPP on a hot day?
A
B
C
D
What is the function of a current transformer?
Measure current
Measure volts
Change current
Change voltage
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
Where should you direct a pyranometer to get the most accurate irradiance reading for your array?
At the horizon
Directly south
In the plane of the array
Away from shading
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
Which of the following will show system components and connections?
Electrical diagram
Sunpath chart
Module spec sheet
IV curve chart
Best sealant for residential rooftop?
Bitumen
Paraffin
Polyurethane
Silicone
Which is the best order of steps to complete before removing equipment during
troubleshooting and maintenance.
Replace fuses, open disconnects, isolate equipment
Open ac and dc disconnects, check breakers, test voltages
Open ac and dc disconnects, isolate equipment, test voltages
Test voltages, check breakers, replace fuses
What is the voltage drop given that volts = 12V, amps = 2A and resistance = 0.2
ohms?
0.4V
6V
12V
24V
After it is determined that there is adequate space on the roof, what is the next
step?
Shade analysis
Connecting inter-module strings
Sending proposal to customer
Putting together a permit
Of the following, which is worst for stand-alone lead-acid batteries?
Undersized PV array
Temperatures between 20C and 30C
Fine stranded conductors
Anti-islanding
Of the following, which is the best benefit of a PV system for a homeowner?
VAR support
Demand response
Self-consumption
Backup power
What would be most important to measure when comparing actual vs. expected
performance as part of commissioning a typical ground mounted PV system?
Imp and Isc
Isc and Voc
Voc and Vsc
Imp and Vmp
What is the power at 20 amps and 380 volts?
7600 kWh
7.6 kW
6 kW
600 kW
A dam is full of water and at the bottom of the dam it is deep and there is an outlet.
If the dam is not so full during a drought, the water will have less potential and this
is an analogy to less
Current
Voltage
Power
Energy
There is a dam full of water and water is released from a pipe at the bottom of the
dam. The amount of water released per second is a hydraulic analogy for
Current
Voltage
Resistance
Energy
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
Which is an example of a multiconductor cable and then a single conductor cable?
USE-2 / RHW-2
DG cable / PV wire
THWN-2 NMC (Romex)
MC cable / DG cable
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 the following is an environmental exposure hazard plan?
Rapid Shutdown
Plansets
SDS
Hydration
How many silicon solar cells in series is best for charging a 12V lead-acid battery
if you are not using a MPPT charge controller?
20
36
60
72
Where do you find the requirements for clear rooftop spaces for firefighters?
NFPA 70
ASCE-7
NFPA 855
IRC
Which of these would cause an interactive inverter to turn off for safety?
Grid is out
Clouds
Warm temperature
Higher PV to inverter ratio
What is the proper slope of an extension ladder?
1:3
1:4
1:5
1:6
Standard Testing Conditions (STC) temperature is:
20C Ambient Temperature
20C Cell Temperature
25C Ambient Temperature
25C Cell Temperature
Undersized PV array (stand-alone)
Decreases voltage drop
Decreases battery life
Increases current drop
Increases resistance
What is the NEC for?
Practical safeguarding of electrical equipment
Workplace safety for employees
Safety for testing electrical equipment
Practical safeguarding of persons and property
A PV system that uses an interactive PV inverter and a battery inverter is called:
Dc-coupled system
Ac-coupled system
Hybrid system
Bimodal system
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
When installing a ballasted PV system on a low slope roof, which is of greater concern to the AHJ?
Shading
Orientation of PV modules
The touching of dissimilar metals
Airflow under PV modules
What is the main function of the Authority Having Jurisdiction?
To check Code compliance
To approve utility interconnections
To ensure worker safety
To make sure that the employer does not discriminate
