Question 1Solar, Emergency & Low-Voltage
What size branch circuit is required for commercial sign?
Correct answer: B. 20A
NEC 600.5(A)
20A — NEC 600.5(A)
NEC Solar PV, Emergency Systems and Low-Voltage Practice Questions
These NEC solar PV and low-voltage practice questions cover Articles 690, 700, 701 and 725. Solar and low-voltage are the fastest growing part of the exam, and they are the part most older study material covers thinly. Article 690 has its own rules for conductor sizing and rapid shutdown that do not look like anything in Chapter 3. Article 725 puts low-voltage circuits into classes that decide what you can run them alongside.
Exam tipPhotovoltaic conductor sizing carries two multipliers, 125% for continuous duty and 125% again for irradiance. Applying only one of them is the standard error and it lands on a wrong answer that has been placed there for you.
Tap an answer to see whether you got it right, the code section it comes from, and the reasoning worked out in full. Nothing to sign up for.
Question 2Solar, Emergency & Low-Voltage
If the sign disconnect is not within sight, it must be _______?
Correct answer: B. Lockable
NEC 600.6(A)(2)
Lockable — NEC 600.6(A)(2)
Question 3Solar, Emergency & Low-Voltage
What is the maximum percentage applied to the PV maximum current when calculating the overcurrent device per 690.8(A)?
Correct answer: B. 125%
NEC 690.9(B)
125% — NEC 690.9(B)
Question 4Solar, Emergency & Low-Voltage
What kind of raceway can photovoltaic (PV) circuits be run in inside a building?
Correct answer: B. metal raceway or Type MC cable
NEC 690.31(D)(1)
metal raceway or Type MC cable — NEC 690.31(D)(1)
Question 5Arc Flash
In other than a dwelling unit, a permanent arc flash label is required on service equipment and feeder supplied equipment rated at least how many amperes?
Correct answer: C. 1000 A
NEC 110.16(B)
1000 A — NEC 110.16(B). In other than dwelling units, and in addition to the general marking in 110.16(A), a permanent arc flash label shall be field or factory applied to service equipment and feeder supplied equipment rated 1000 amperes or more.
Answer: 1000 amperes or more.
Question 6Arc Flash
Besides the warning itself, what must the permanent arc flash label required by 110.16(B) include?
Correct answer: A. The date the label was applied
NEC 110.16(B)
The date the label was applied — NEC 110.16(B). The label shall be in accordance with applicable industry practice and include the date the label was applied.
Answer: the date it was applied.
Question 7Arc Flash
Does the arc-flash hazard warning marking of 110.16 apply inside dwelling units?
Correct answer: A. No — it applies in other than dwelling units
NEC 110.16(A)
No — NEC 110.16(A) and (B) both begin with the words “in other than dwelling units.” A house panel is outside this section.
Answer: it applies in other than dwelling units.
Question 8Arc Flash
Under 110.16(A), what makes arc-flash warning marking required on switchgear, enclosed panelboards and motor control centers?
Correct answer: A. They are likely to require examination, adjustment, servicing or maintenance while energized
NEC 110.16(A)
Likely to be worked while energized — NEC 110.16(A). The trigger is the likelihood of examination, adjustment, servicing or maintenance while energized, not the voltage and not the amperage.
Answer: likely to be worked while energized.
Question 9Arc Flash
The NEC requires arc-flash labeling but not the arc-flash calculation. Which standard does it point to for the industry practice behind the label?
Correct answer: A. NFPA 70E
NEC 110.16(B)
NFPA 70E — Informational Note No. 2 to NEC 110.16(B) points to NFPA 70E, Standard for Electrical Safety in the Workplace, for the applicable industry practices for equipment labeling. The incident-energy calculation itself is IEEE 1584. Neither is in the NEC, which is why you will not find an arc-flash formula in the code book.
Answer: NFPA 70E.
Question 10Arc Flash
The arc-flash marking required by 110.16(A) must be located so that it is what?
Correct answer: A. Clearly visible to qualified persons before they examine or service the equipment
NEC 110.16(A)
Clearly visible before the work — NEC 110.16(A). The marking shall meet the requirements in 110.21(B) and shall be located so as to be clearly visible to qualified persons before examination, adjustment, servicing or maintenance of the equipment. A label you have to open the door to read defeats the purpose.
Answer: clearly visible before the work starts.
These are 10 of 803 questions
The full course carries 654 code and calculation questions plus 149 photo questions taken on real job sites — my own photographs from 17 years of electrical inspections. Every one of them is worked out like the ones above.
- NEC 2023 and NEC 2026 both included, switch between them any time
- Every question names the code section, so you learn to find it in the book
- The whole course reads itself out loud, with the words highlighted as they are spoken
- Timed 80-question practice test built like the real exam
- Video lessons, drive-along audio and flash cards that bring back what you miss
Work at it and still fail twice inside your six months, and you get the $200 back.
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