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NABCEP ASSOCIATE PRACTICE TEST QUESTIONS, Exams of Advanced Education

Cheyney University of PennsylvaniaAdvanced Education

NABCEP ASSOCIATE PRACTICE TEST QUESTIONS

Typology: Exams

2025/2026

Available from 03/23/2026

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NABCEP ASSOCIATE PRACTICE TEST
QUESTIONS
1. 16. A 48 volt battery bank is used to provide power for critical loads
requiring 7458 Wh/day. Three days of autonomy are required. What is
the required
capacity of the battery bank?: 16. Answer: b. 466 Ah
7458
Wh
÷
48V
=
155.4
Ah/day
155.4 Ah/day x 3 days autonomy = 466 Ah
2. 1. NEC section shows the requirements for
working spaces around live electrical equipment?: 110.26
3.
2.
What
is
the
maximum
latitude
at
which
the
sun
can
achieve
a
90º
altitude
angle?:
2. Answer: b. Approx. 23.45º north and south of the equator, but like magnetic
declination, the latitude of
the
Tropics
varies
over
time.
4. 3. If the open circuit voltage of a polycrystalline silicon PV module is
37.0V, the module Vmp is 29.9V, the inverter max voltage is 600VDC and
its MPPT voltage range is 300 to 480VDC, and the minimum temperature
is -24°C. What is the maximum number of modules per source circuit
according to the NEC? List the
NEC section where the answer is found.: 3.
Answer C: 37V x 1.20 = 44.4V
600V max ÷ 44.4V = 13.4 ’13
modules
NEC Table 690.7 - 1.20
pf3
pf4
pf5
pf8
pf9
pfa
pfd

Partial preview of the text

Download NABCEP ASSOCIATE PRACTICE TEST QUESTIONS and more Exams Advanced Education in PDF only on Docsity!

1 /

NABCEP ASSOCIATE PRACTICE TEST

QUESTIONS

    1. A 48 volt battery bank is used to provide power for critical loads requiring 7458 Wh/day. Three days of autonomy are required. What is the required capacity of the battery bank?: 16. Answer: b. 466 Ah 7458 Wh ÷ 48V = 155.4 Ah/day 155.4 Ah/day x 3 days autonomy = 466 Ah
    1. NEC section shows the requirements for working spaces around live electrical equipment?: 110.
    1. What is the maximum latitude at which the sun can achieve a 90º altitude angle?: 2. Answer: b. Approx. 23.45º north and south of the equator, but like magnetic declination, the latitude of the Tropics varies over time.
    1. If the open circuit voltage of a polycrystalline silicon PV module is 37.0V, the module Vmp is 29.9V, the inverter max voltage is 600VDC and its MPPT voltage range is 300 to 480VDC, and the minimum temperature is -24°C. What is the maximum number of modules per source circuit according to the NEC? List the NEC section where the answer is found.: 3. Answer C: 37V x 1.20 = 44.4V 600V max ÷ 44.4V = 13.4 ’ 13 modules NEC Table 690.7 - 1.

2 / correction factor

    1. A PV array of Suniva 300 Watt modules consists of 3 rows and 10 columns of racked modules mounted in landscape and facing south at latitude 30°. The modules are tilted at 20⁰. The mounting posts are installed 3 ft. deep. How long must the posts be? Module dimensions are 77.6" x 38.7".: Answer: C Sin(angle) = opposite ÷ hypotenuse Sin(20⁰) = Height ÷ 38.7" x 3 Height = sin(20⁰) x 116.1" Height = 0.342 x 116.1" = 39.7 " 39.7" + 36" = 75.
  2. An array located at 30⁰N latitude consists of two rows racked facing south. Both rows are on a level surface and the height from the ground to the highest point on the module is 39.7". Calculate the minimum distance in feet needed between rows so the modules will not be shaded at 9AM on December 21. Use the sun chart provided.: Answer: b Tan(angle) = opposite ÷ adjacent where opposite is array height and adjacent is row-to-row spacing Tan(21°) = 39.7" ÷ Row- to-row Row-to-row = 39.7" ÷ 0. Row-to-row = 103.4" or 8.
    1. At 43⁰ North latitude on the winter solstice, the solar altitude angle at noon is .: d. 23.55⁰ 90° - 43° (latitude) + (-23.45°) = 23.55°

4 /

  1. Answer: c. Table 250. NEC Article 690.45(A) refers to Table 250.
    1. There are to be two critical loads on a PV system. Your analysis shows that one uses 1900 Wh/day and operates for 6 hrs. per day and the other uses 1200 Wh/day and operates for 3.5 hrs. What is the weighted average operating time?: 11. Answer: b. 5 hrs./day (1900 Wh/day x 6 hrs.) + (1200 Wh/day x 3.5 hrs.) / (1900 Wh/day + 1200 Wh/day) = 5 hrs. Divide top by the bottom
    1. What is the combined effect in wattage of the 2 loads in the previous question?: 12. Answer: b 620 Watts (1900 Wh/day + 1200 Wh/day) /5.0 hrs. = 620W
    1. The critical design month is the worst case scenario where the load and the are used to design the PV system.: 13. Answer: d. Insolation data
    1. Active means of charge control is required by the NEC unless the max- imum array charge current for 1 hour is less than % of the rated battery capacity measured in amp/hours.: 14. Answer: b. 3% See NEC 690.
  6. 1
  7. When battery temperature is high, temperature compensation the VR set point to minimize the excessive over charging and reduce electrolyte losses.: 15. Answer: a Lowers
    1. Critical loads operate for 12 hours. Three days of autonomy

5 / are required and the preferred depth of discharge of 50%. What is the average discharge rate?: 17. Answer: b. C/ 12 hrs./day x 3 days autonomy = 36 hrs 36 hrs. ÷ 0.5 DOD = 72 hrs. = C/

    1. A battery bank of 500 Ah is required. The depth of discharge is 50%, the minimum operating temperature is -10ºC and the average discharge rate is C/128. According to the manufacturer's specs. this yields a temperature and discharge rate derating factor of approximately 73%. What is the required battery bank capacity?: 18. Answer: b. 1370Ah Given 50% DOD, the battery bank must be: 500 Ah ÷ 0.5 = 1000 Ah Because 27% of the capacity is lost due to cold temperatures per the manufacturer: 1000 Ah ÷ 0.73 = 1369.9 Ah =1370Ah
    1. A battery bank must supply 1200 Ah and will operate at 48V. The battery selected is an 800 Ah battery. How many 6V batteries will be required in this battery bank?: 19. Answer: b. 16 48V bank ÷ 6V battery = 16 batteries in series to achieve voltage 1200 Ah ÷ 800Ah = 1.5! 2 parallel strings of batteries 8 x 2 = 16 Nothing was mentioned about DOD.
    1. A PV system needs to supply 5834 Wh per day. The daily

7 / overcurrent devices are addressed?: 25. Answer: d. Article 240

    1. You are inspecting a PV system in Oregon. The array is facing south on a 6/12 pitch roof and the PV equipment is on the east side of the house 60 feet from the combiner. You see an SMA inverter with a #6 GEC run to the ground rod. To the right, is a 30A disconnect with EMT extending to the roof. Inside the disconnect you see two black PV conductors landed onto the terminals. Your inspection of the combiner box on the roof shows two black PV wires. Each one is terminated on a fuse holder and the ground wire is terminated on the ground bus. What type of PV system are you inspecting?: 26. Answer: c. Ungrounded
    1. USE-2 wire must be strapped and secured between modules at intervals no more than:: 27. Answer: c. 4.5' Installation methods for exterior USE-2 conductors, commonly used in PV arrays, are stated in NEC 338.10(B)(4). This section refers to Article 334.30 for support methods. Article 334 is entitled Non-Metallic Sheathed Cable (often referred to by the trade name Romex). The requirements for fastening NM cable are well understood by AHJ. (Field Inspection Guidelines by Bill Brooks)
    1. If the uplift force on a system is 1,200 pounds with a safety factor of 1.5, what is the uplift force with a safety factor of 2?: 28. Answer: d. 1600 lbs 1200 lbs ÷ 1.5 = 800 lbs 800 lbs x 2 = 1600 lbs
    1. When GFP is used on an inverter, the grounded and grounding

8 / conduc- tors should be:: 29. Answer: d. Grounding: Connected to case, Grounded: Bonded to grounding

    1. A customer in New Mexico has a 6000W grid-tied PV system. Every day around noon during the summer, the 25A solar breaker trips. The inverter is on the south side of the house. The conduit run from the inverter to the transition box is 200 ft. The array is facing true south at latitude. What should be done to prevent the breaker from tripping?: 30. Answer: b. Increase the breaker size. 6000W ÷ 1.2 = 5000W inverter 5000W ÷ 240V = 20.8A 20.8A x 1.25 = 26.04A A 30 amp breaker was needed for this system
    1. You are on a roof in December to check system production compared with the expected production. You know there will be some shading around 3 p.m. In addition to a multi-meter, what tools will you need?: 31. Answer: c. Irradiance meter and temp. gauge
    1. When checking short-circuit current on a string of modules, what do you do first?: 32. Answer: d. Measure operating current You must verify that the circuit is in the open position before you loosen any terminals to which the conductor is attached.
    1. When troubleshooting modules, what do you do?: 33. Answer: a. Disconnect all loads to prevent module arcing when unplugged

10 / Rebar comes in 1/8 in. increments. Rebar is required to be no smaller than ½ in. 1/8 = 0. 0.5 ÷ 0.125 = 4

    1. A 55 foot tree will grow 25 feet during the life of the PV system. How far away does a ground mount system need to be? The system is located at 40 degrees latitude, the sun's lowest altitude angle is 14 degrees and the azimuth angle is 41 degrees.: 39. Answer: d. 330' 55' + 25' (tree height at leading edge) / Tan(14⁰) I did not multiply by the COS (41) because the question does not say that the array is due north of the tree. = 320.8'
    1. A weather vane falls onto an array and there is broken glass. The system is still working. What is the main safety concern and how do you handle it?: 40. Answer: d. Vane has high potential. Open DC disconnect, unplug all modules and remove vane with voltage rated gloves.
    1. What is the most important consideration for construction of a ground mount array in a heavy snow area?: 41. Answer: b. Distance from ground to bottom of array Incorrect answers: a, Tilt angle. Typically on a ground-mount the array will be at latitude. Even at latitude -15⁰ in areas where there is lots of snow this angle will allow snow shedding. b. Row-to-row shading. The question did not mention multiple rows. c. Could be correct but not the most accurate choice.
    1. System drawings call for #10 wire. The system calls for a 50 amp breaker. What size should the wire be?: 42. Answer: b. # NEC 240.4(D) (7) Copper #10 limited to a 30A overcurrent device.

11 / NEC Table 310.15(B)(16) in either 75 or 90 degree column shows #8 good for a 50A breaker

    1. At what depth should a 1/0 ground wire be buried?: 43. Answer: c. 30" A 1/0 ground wire is actually a ground ring, per Article 250.52 (A) (4) Article 250.53 (F) states that a 30" minimum burial depth for a ground ring is required.
    1. An inverter is on the north side of a house and the array is on the south. Where should the DC and AC disconnects be? a. The DC disconnect should be close to the array and the AC disconnect should be next to the inverter.: 44. Answer: d. The DC and AC disconnects should be on either side of the inverter. NEC 690. Incorrect answers: a. and c. Neither of these satisfy the "readily accessible" requirement. b. Since we don't know from the question that the main service is in an accessible location, stipulating that the disconnects go close to the main service does not by itself satisfy 690.
    1. At what distance from the junction box must USE-2 wire be secured?: 45. Answer: b. 12" NEC 334.
    1. The power loss due to temperature for a silicon module is listed as -0.5%/ ⁰C in the manufacturer's specifications. The manufacturer recommends two array mounting options; one with a ¾" air gap between the module and the roof and one with a 3" air gap. The closer mounting system causes the array to operate 10⁰C hotter on average throughout the year. Which mounting system will produce the most energy? How much?: 46. Answer: b. 3" gap by 5%

13 / 765 lbs. ÷ 27 lbs. (block weight) = 28.3! 29 blocks per frame 15 (frames required) x 29 (blocks) = 435 blocks to ballast the system

    1. What is the approximate dead load within the system footprint that the roof must withstand?: 49. Answer: b. 21 lbs./sq. ft. 925 lbs. ÷ (9 ft. x 5 ft.) = 20.56 lbs./sq. ft
    1. A utility interactive PV system is installed on a commercial building. The array is roof mounted and operates at 372Vmp with an operating current of 8.56A. When inspecting the source circuit combiner box located next to the array, you observe the following: the ungrounded PV source circuit conductor is black USE-2/RHW-2, the frame grounding conductor is # solid Cu, the box is a NEMA4 rated metal box, the PV output conductors leave the (+) and (-) terminal busses and pass into a male EMT adapter secured with a locknut. What is required to bring the combiner box into compliance with the NEC?: 50. Answer: d. None of the above Solution 250.97 states that, for circuits of over 250V to ground, the electrical continuity of metal raceways ... shall be ensured by one or more of the methods specified for services in 250.92(B) 250.92(B)(1-4)