Try five free South Carolina electrical practice questions with answers and 2020 NEC references. This set uses the 2020 NEC for South Carolina’s commercial Electrician exam. The Residential Electrical test uses the 2017 NEC; residential candidates should use the linked 2017 practice test instead. Work with your code book open, record your answers, then open the explanations below.
Start with the South Carolina exam guide for the official bulletin, approved books, exam format and registration steps.
Study on the edition your exam uses. JCR's South Carolina Commercial course follows the 2020 NEC on the Electrician exam, and the 2017 NEC self-study bundle fits the residential exam. Each costs $495 and comes with a mock exam bank of 500+ questions, more than 20 hours of video, JCR's 152-page workbook and permanent tabs for your code book.
Which South Carolina exam are you preparing for?
| Quick facts | SC electrical exam |
|---|---|
| Test company | PSI, on a computer at a test center |
| Commercial Electrician | 80 questions, 5 hours, 56 correct to pass (70%), $78 |
| Residential Electrical | 60 questions, 180 minutes, 44 correct to pass (73.3%), $75 alone or $94 with the business exam |
| Approval before booking | Commercial: none. You apply to the Contractor's Licensing Board after you pass. Residential: you need an eligibility letter from the Residential Builders Commission first. |
| Retakes | Commercial: 2 tries per 12 months, then 1 every 6 months. Residential: 3 tries in your 12-month eligibility. |
Commercial applicants also need Business and Law and the other trade references. Residential candidates should follow the 2017 NEC outline, not this 2020 set.
South Carolina electrical practice test: 5 questions
Use 15 minutes as a practice target. This is a short NEC lookup drill, not a full-length exam or a prediction of your score. Questions are selected from JCR’s practice bank and may also appear in other JCR state guides.
Question 1: Working space
A 480Y/277-volt switchboard has exposed live parts on both sides of the aisle in front of it. What is the minimum depth of working space?
- 3 feet
- 3½ feet
- 4 feet
- 5 feet
Question 2: Grounding
A branch circuit is protected by a 60-amp breaker. What is the smallest copper equipment grounding conductor allowed for it?
- 12 AWG
- 10 AWG
- 8 AWG
- 6 AWG
Question 3: Conduit fill
Five individual conductors are installed in a complete conduit run longer than 24 inches. No special fill allowance applies. What is the most of the conduit's cross-section they may fill?
- 31 percent
- 40 percent
- 53 percent
- 60 percent
Question 4: Motors
A 10 hp, 230-volt, single-phase motor runs in continuous duty. What is the minimum ampacity for its branch-circuit conductors?
- 50 amps
- 57.5 amps
- 62.5 amps
- 68.75 amps
Question 5: Appliances
A 50-gallon storage water heater is rated 4,500 watts at 240 volts. What is the minimum ampacity for its branch-circuit conductors?
- 18.75 amps
- 20 amps
- 23.44 amps
- 28.13 amps
Answer key with 2020 NEC sections
Finish all five before opening the answers. Give yourself one point for each correct choice, then look up every missed section.
Show the answer to question 1Hide the answer to question 1
1. C, 4 feet (NEC Table 110.26(A)(1))
The switchboard is 277 volts to ground, which falls in the 151–600 volt row. Exposed live parts on both sides is Condition 3, so the minimum depth is 4 feet. Condition 2 (grounded parts across the aisle) would be 3½ feet. See all three conditions explained.
Show the answer to question 2Hide the answer to question 2
2. B, 10 AWG (NEC Table 250.122)
Table 250.122 sizes the equipment grounding conductor by the overcurrent device ahead of it. For a 60-amp device, the minimum is 10 AWG copper or 8 AWG aluminum. See more Table 250.122 examples.
Show the answer to question 3Hide the answer to question 3
3. B, 40 percent (NEC Chapter 9, Table 1)
Over 2 conductors may fill 40% of the conduit. One conductor may fill 53%, and two may fill 31%. See a full conduit fill example.
Show the answer to question 4Hide the answer to question 4
4. C, 62.5 amps (NEC Table 430.248 and 430.22)
Use the table current, not the nameplate. Table 430.248 lists 50 amps for a 10 hp, 230-volt single-phase motor. Section 430.22 requires 125% of that: 50 × 1.25 = 62.5 amps. The 57.5-amp choice is the table value for a 200-volt motor.
Show the answer to question 5Hide the answer to question 5
5. C, 23.44 amps (NEC 422.13)
The heater draws 4,500 ÷ 240 = 18.75 amps. Storage water heaters of 120 gallons or less get branch-circuit conductors and overcurrent protection sized at no less than 125% of their rating: 18.75 × 1.25 = 23.44 amps.
How to study after this practice test
- Log the lookup. Write down the article, section or table you used and how long it took to find.
- Work the calculation again. Keep the units and intermediate steps so you can find an arithmetic error.
- Use your exam’s edition. A newer installation code is not automatically the edition used for your license test.
- Cover the full outline. Commercial applicants also need Business and Law and the other trade references. Residential candidates should follow the 2017 NEC outline, not this 2020 set.
South Carolina electrical practice test FAQ
Are these actual licensing exam questions?
No. These are JCR practice questions selected to help you study NEC rules. They are not supplied or endorsed by the exam vendor or licensing board.
Does getting all five right mean I am ready?
Five questions are too small a sample to judge readiness. Use a full practice exam, review the official content outline and practice every required subject.
Which NEC edition does this practice test use?
This set uses the 2020 NEC. This set uses the 2020 NEC for South Carolina’s commercial Electrician exam. The Residential Electrical test uses the 2017 NEC; residential candidates should use the linked 2017 practice test instead.
Keep practicing for your South Carolina exam
Use the course links above for the exam and edition you are taking. Review the complete South Carolina exam guide before you order.
Try JCR’s free NEC practice app. Check the edition shown in the app before using its questions for your exam.
More South Carolina guides
Sources and answer references
- PSI SC Commercial Contractor bulletin (August 27, 2026)
- PSI SC Residential Builders bulletin (October 9, 2026)
- SC CLB: Licensure with the Board
- SC RBC: Residential Electrician license
- PSI: SC commercial contractor exams
- PSI: SC residential exams
- NFPA 70, 2020 edition: see the section citations in each answer.
- JCR washington electrical practice test: source practice-bank questions.
- JCR new mexico electrical practice test: source practice-bank questions.
- JCR maryland electrical practice test: source practice-bank questions.
Reviewed October 22, 2026. NEC answers and section references checked against the stated edition in NFPA LiNK. Exam information follows the linked official bulletins. Questions are selected from JCR’s shared practice bank, with clarifications where needed.