Exam (elaborations)
Certification Questions and Answers 2024
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Exam of 11 pages for the course Enphase at Enphase (Certification)
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CertificationWhat subsection of the utility grid typically operates at the lowest voltage? - answer
Service
A PV module operates a DC water pump directly for 2 hours. The module produces 3A,
and the water pump voltage is 16V. how much energy does the PV module deliver to
the pump? - answerd. 96 Wh. 16 x 3 = 48 x 2 = 96
Which sensor would be used to measure irradiance during troubleshooting of a PV
system? - answerPyranometer
How should penetrations or structural attachments to roofing systems be treated in
order to protect against leakage? - answerFlashed
When sizing a PV system, it is necessary to know the lowest possible temperatures at a
site to prevent: - answerOvervoltage
Due to its light weight and longevity, which is the most common material used for
racking on sloped-roof systems? - answerAluminum
A grid tied system is rated at 3.5 kW. Assuming 10% power loss through the system,
what would be the expected average monthly output in a location that averages 5 sun
hours a day? - answerc. 472kWh
3,500 x .10 = 350
3,500 - 350 = 3,150
3,150 x 5 = 15,750
15,750 x 30 = 472,500 => 472
What is the benefit of a utility interactive PV system without energy storage? -
answerReduces fossil fuel generation
In hot and humid marine climates, which type of fastener is recommended? -
answerStainless steel
Based on the sun chart below, what is the approximate altitude of the sun at noon on
December 21? - answer20
Which of the following represents best practice when handling modules exposed to
sunlight? - answerTreat all wires as though live current is present
, What is the best sequence of steps to take when troubleshooting a PV array string that
is supplying any current? - answerTurn off the inverter and disconnect the affected
string
Measurements of an array on a sunny spring afternoon show 89.7 V and 14.4 A at the
input of
the charge controller. The module electrical characteristics are as follows:
Maximum power: 255 W
Vmp: 31.5 Vdc
Imp: 8.1 A
V: 38.3 Vdc
Isc: 8.8 A
Maximum system voltage: 600 V
Maximum series fuse: 15 A
How are the PV modules configured electrically? - answerSix modules are in use: 3 in
series, 2 strings in parallel
89.7 ÷ 31.5 ~ 3 panels
31.5 x 3 = 94.5
The average electrical power over a given period is equal to the accumulated electrical
energy divided by: - answertime
A stand-alone system consumes an average of 3kWh each day from the battery bank
with a 98%
round trip efficiency. Given that the charge controller operates at 95% efficiency and
that winter days have as little as 3.5 hours of peak sun, what is the minimum number of
120 W modules required for this system? - answer8. 3,000 ÷ 120 = 25
25 ÷ 3.5 = 7.14
Wind load uplift forces are usually measured in which units? - answerPounds per
square foot
Which type of PV array mounting system would be preferred for a flat commercial roof
application where it is desired to avoid direct structural attachments and penetrations
through the roofing system? - answerBallasted mount
Which of the following is the primary responsibility of the authority having jurisdiction
(AHJ)? - answerTo evaluate installations for code compliance
Maximum power point trackers adjust which array parameter? - answerTilt angle
Which device is wired in parallel with groups of cells in a solar module to prevent
reverse bias voltage caused by partial shading? - answerBypass diode
The solar window represents the range of sun paths at a given location between the: -
answerSummer and winter solstices
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