PV Tech
Load side connections require that the total rating of the breakers supplying power to the busbar to not exceed __________ of the rating.
120%
What is the minimum overcurrent protection for a PV source circuit consisting of modules with a rated short circuit current of 8.8 amps?
13.75, or a more common 15 amp fuse/breaker
At an initial estimate, a 2.5 kW array of crystalline silicon PV requires approx. ________ square feet of available space
250
If two 60-watt light bulbs are left on for 2.5 hours, they will consume ________ W-hrs.
300
A crystalline silicon PV module with a maximum power point voltage (Vmp) around 18 volts is likely made up of how many individual PV cells
36
A PV module generates 3 amps at 12 volts. The power produced is:
36 watts
Preliminary system sizing indicates that the target size for the PV array is 12.6W. If 315W modules are to be used for the array, which design matches the target size?
4 parallel strings of 10 modules in series
AWG stands for _______________.
American Wire Gauge
Which of the following equipment allows for module level maximum power point tracking?
Both microinverters and DC-DC converters
_______ PV modules currently dominate the market.
Crystalline silicon
What is the primary purpose of the site evaluation tools such as the Solar Pathfinder:
Evaluate shading
A conductor has more resistance than an insulator.
False
Sunlight intensity primarily affects voltage of a module.
False
The photovoltaic effect produces alternating current.
False
A multimeter is a tool used to measure sunlight intensity.
False Pyronometer is the correct device.
GEC stands for
Grounding electrode conductor
What is the most common mounting type for residential grid-direct systems?
Roof mount
The "I-codes" -- including the international fire code (IFC) - require access pathways for roof-mounting PV systems.
True
A string inverter with two MPPTs allows for:
Two PV source circuits of different lengths to be connected
when testing the Voc of a module, what is the correct setting for a digital multimeter.
VDC
A PV array is connected to a grid-direct inverter and is operating at STC. The array output should be closest to:
Vmp and Imp
Which one of the following lists correctly defines the parameters that affect voltage drop?
Wire size/gauge, circuit current, circuit voltage, and circuit length
Which of the following is a disadvantage of low slope (ballasted) roof?
additional weight may require additional engineering
when calculating wire size for various circuits, ampacity and voltage drop calculations will often result in different sizes. Which size should be selected?
always pick the larger of the two wires.
the unit measure for electrical current in a conductor is the:
amp
The amount of current a conductor can carry is defined as its
ampacity
The amount of current a conductor can carry is defined as its________.
ampacity
A micro inverter is wired to....
an individual module
In order to meet _______________ requirements, if utility power shuts down, a grid-direct inverter must also shutdown.
anti-islanding
The equipment grounding conductor must be ______
bare wire, green, or green with yellow strips
Which of the following are components of pitched roof mounts?
center clips, end clips, attachment feet, rails
Ground mounted PV has the following advantages EXCEPT:
cheaper installation costs
Roof mounts have the following advantages except:
cooler cell temperatures
sunlight intensity primarily affects what component of a module's power output?
current
At a grid-direct string inverter ungrounded conductors must have a ______________ means to isolate the inverter from all power sources.
disconnecting
1 AWG is larger than 1/0 AWG
false
14 AWG is larger than 6 AWG.
false
A pyronometer measures temperature.
false
An 8AWG aluminum conductor can carry more current than an 8AWG copper conductor.
false
International code council requires access pathways of 6' for emergency personnel.
false
Measuring the solar resource and shade is the only thing to do during a site assessment.
false
Metal roof mounts are flash mounts.
false
The purpose of an inverter is to change alternating current to direct current.
false
The purpose of the solar pathfinder is to measure roof angle.
false
The rating of the overcurrent protection device must be greater than the ampacity of the conductor it protects.
false
When testing the Voc of a module, the correct setting for a digital multimeter is Volt (AC)?
false
under normal operating conductor, the equipment grounding conductor(S) will carry current
false
Low-slope ballasted mounts always require mechanical attachment to the roof structure.
false instead we use concrete blocks.
Which of the following is a primary differences in wire type?
insulation material
Which one of the following does not affect the power output of a PV module
inverter efficiency
Which of the following doesn't affect variation in solar raditation
inverter type
the grounded conductor is a __________ that is intentionally connected to the grounding system at one point.
isolated conductor
Grid-direct inverters use ____________ to operate the connected array at the highest wattage "knee" of its IV curve.
max. power point tracking
in order to meet national electrical code (NEC) requirements, the equipment grounding conductor __________
must be an effective, low resistance, electricallt conductive path
In a series connection, the positive lead of one module connects to the ____________ lead of the next module.
negative
When a fuse blows or a circuit breaker trips, it _____________ the circuit, protecting the conductor
open
Properly sized and located overcurrent protection devices (OCPD) will:
protect a conductor from current exceeding the conductors capacity
What is NOT a benefit of grid direct inverters?
provides backup power
Consider two identical 5kW PV systems. The array of the second operates at twice the voltage of the other. What is one benefit of the increase voltage?
smaller wire gauge required
Isc
the amount of amperage which a module or array will produce when its positive and negative leads are directly connected together with no load (no resistance) in between.
VoC
the measured voltage, between the positive and negative leads when a PV module/ array is exposed to sunlight but not connected to a circuit (there is infinite resistance between positive and negative)
Maximum power point
the point on the IV curve where the product of voltage time current is the greatest (equaling the most watts)
A PV array with a DC STC rating of 7500 watts installed connected to a grid-direct inverter with a maximum AC output power of 6000 watts is appropriately sized.
true
A PV source circuit carrying 12 amps is approx. sized with 12 AWG THHN.
true
A load-side connection for an inverter occurs on a breaker in a similar manner to all other circuits in the home or business.
true
A supply-side connection means the AC output on the Inverter is connected on the utility side of the Main AC service.
true
Ballasted roofs mounts are the most common in residential applications
true
Flashing is a structural components inserted under the roof covering to ensure the shedding of water and offer the best leak protection.
true
If a grid-direct PV system has two PV source circuits, overcurrent protection is not normally required on the individual circuit conductors.
true
Irradiance is measure in watts / m2 and is a measure of power.
true
Metal, shingle and low slope rubber roofs with appropriate racking are suitable for mounting PV panels.
true
PV source conductors inside a building must be in metallic conduit instead of PVC.
true
Rail-free installations have a potential for cost savings but the installation can be a little more difficult.
true
The bulk of the solar irradiance reaches a site between 9am-3pm
true
The primary purpose of overcurrent protection (circuit breakers and fuses) is to prevent conductors from overheating and potentially causing a fire
true
When using DC-to-DC converters on a PV array that will be connected to the grid, an inverter is still required.
true
to increase the voltage of a PV source circuit, PV modules are connected in series.
true
Temperature primarily affects the ____________ of a module.
voltage
A grounded (current-carrying) conductor must be _______________.
white or gray