Start Practice Test

South Carolina Residential Electrical Practice Exam

What This Practice Exam Covers

The real South Carolina Residential Electrical exam is 60 questions, 180 minutes, and you need a 74% — 45 correct answers — to pass. It pulls from 9 topic areas, with item counts per topic fixed by the official test provider.

Two options here:

Free practice exam: 10 questions per attempt, drawn from a limited pool. You can retake it as many times as you want. Use it to get comfortable with the format and the way questions are worded before committing to a full session.

Full practice exam (paid): 60 questions, 180-minute timer — same format as the real thing. Questions come from a pool of 481+ items, so every attempt is a different exam. No duplicate runs. Coverage matches the exact topic list provided by the official test provider, so you're not drilling on anything that won't show up on test day.

Start free. If you're serious about passing, move to the full exam.

What You'll Be Tested On

General Electrical Knowledge — 13 items

The single heaviest topic. Expect calculations, not just definitions. You need to work Ohm's Law in series, parallel, and combination circuits — voltage, current, and resistance. Power calculations (P = IV, P = I²R, P = V²/R) show up directly. AC theory questions cover concepts like impedance, power factor, and the relationship between voltage and current in inductive circuits. Voltage drop for branch circuits and feeders requires you to apply the formulas in NEC Handbook, Chapter 9, Table 9 and Table 8. Troubleshooting questions ask you to identify which test instrument to use and how to interpret readings. Definitions from NEC Handbook, Article 100 — including Ampacity, Continuous Load, GFCI, and Grounding Electrode Conductor — are fair game here and throughout the exam.

Services, Feeders, and Branch Circuits — 15 items

The heaviest topic by item count. You need to know service installation rules — number of services allowed per building (NEC Handbook, Section 230.2), service conductor sizing (NEC Handbook, Section 230.42(A)(1)), and disconnect requirements (NEC Handbook, Section 230.71(A) and 230.79(C)). Feeder questions pull from NEC Handbook, Sections 215.2(A)(1)(a) and 215.3. Branch circuit questions cover GFCI locations per NEC Handbook, Section 210.8(A)(7), multi-wire branch circuits per Section 210.4, and required lighting outlets per IRC Section E3903.3.1. Temporary installation rules come from NEC Handbook, Section 590.4. Motor installation in dwellings requires knowledge of NEC Handbook, Sections 430.22 and 430.52, including how to use Table 430.52 for overcurrent protection sizing. Three-phase service questions test system identification and load calculations per NEC Handbook, Section 220.5(A).

Overcurrent Protection — 5 items

Know NEC Handbook, Sections 240.4(B), 240.4(C), and 240.4(D) cold — these govern how you size protection for specific conductor types. Section 240.4(D) lists maximum OCPD ratings for small conductors (14, 12, and 10 AWG). The 125% continuous load rule from Section 210.20(A) connects directly here. Know what "next larger standard size" means and when you can and cannot use it.

Grounding and Bonding — 6 items

Table work is mandatory. Grounding electrode conductor sizing uses NEC Handbook, Table 250.66 (also IRC Table E3603.4). Equipment grounding conductor sizing comes from NEC Handbook, Table 250.122. Know the difference between the grounding electrode conductor, the equipment grounding conductor, the main bonding jumper (NEC Handbook, Article 100), and the system bonding jumper. Questions on where grounding connections are made and what constitutes a grounding electrode (NEC Handbook, Section 250.50) are common. NEC 250.52(B)(3) tells you what cannot be used as a grounding electrode — know that list.

Conductors and Cables — 5 items

Underground conductor burial depths come from NEC Handbook, Table 300.5. Vertical conductor support rules use NEC Handbook, Section 300.19(A) and Table 300.19(A). Conductor selection requires reading NEC Handbook, Table 310.104(A) for insulation types and temperature ratings, and applying correction factors from NEC Handbook, Table 310.15(C)(1). Cable-type questions distinguish between Type AC (NEC Handbook, Section 320.24), Type MC (Section 330.24(B)), and Type NM (Section 334.10, 334.12). Know where each type is permitted and where it is prohibited.

Raceways and Boxes — 4 items

Conduit fill uses NEC Handbook, Chapter 9, Tables 1, 4, and 5. Know maximum conduit fill percentages for 1, 2, and 3+ conductors. RMC questions draw from NEC Handbook, Sections 344.20(A), 344.22, and 344.26. EMT is covered in Sections 348.20(A), 348.22, and 348.30(A). RNC appears in Sections 352.10(F) and 352.12. Box fill calculations require NEC Handbook, Section 314.16(B) and Table 314.16(B) — each conductor type has a specific volume allowance.

Lighting — 4 items

Know fixture weight limits — a ceiling outlet box must support a luminaire up to 50 pounds without independent support (IRC Section E3905.6.2). Recessed fixture clearance and insulation rules come from NEC Handbook, Sections 410.16(B) and 410.16(C). Track lighting calculations use Section 220.43(B). Fixture grounding requirements pull from NEC Handbook, Section 410.44.

Specialty — 4 items

Pool, spa, and hot tub bonding uses NEC Handbook, Section 680.42(A)(2) for portable spas and related articles for permanently installed pools. Lighting near water has strict distance and GFCI rules. Generator questions reference NEC Handbook, Section 445.13(A) for conductor ampacity. Wheelchair lift wiring comes from NEC Handbook, Section 620.21(C)(1) and 620.38. Garage installation questions will test GFCI requirements and permitted wiring methods.

Safety — 4 items

Questions come from 29 CFR 1926, covering PPE (§1926.28(a) and §1926.95(d)(1)), emergency action plans (§1926.35(e)(3)), first aid requirements (§1926.50(c) and §1926.50(d)(2)), and hazard communication (§1926.59). Know who is responsible for providing PPE, what training triggers the requirement, and the minimum first aid kit requirements.

Worked Sample Questions

Question 1 — Services, Feeders, and Branch Circuits

A panelboard has a continuous load of 80A. What is the minimum OCPD size?

• A. 80A
• B. 90A
• C. 100A
• D. 110A

Correct Answer: C — 100A

A continuous load is any load expected to last 3 hours or more. Per NEC Handbook, Section 210.20(A) and the Article 100 definition of Continuous Load, the OCPD must be sized at no less than 125% of the continuous load. Multiply: 80A × 1.25 = 100A. That lands exactly on a standard OCPD size, so 100A is your answer. If the math had landed between standard sizes, you'd move up to the next standard size.

Question 2 — General Electrical Knowledge (Lighting)

A residential electrician is installing a ceiling-mounted outlet box that will solely support a luminaire. What is the maximum weight of a luminaire the box must be capable of supporting without independent support?

• A. 35 pounds
• B. 70 pounds
• C. 50 pounds
• D. 6 pounds

Correct Answer: C — 50 pounds

Per IRC Section E3905.6.2 (parallel to NEC 314.27(A)(2)), an outlet box used exclusively for lighting support must handle a luminaire up to 50 pounds without independent support. Anything heavier than 50 pounds requires support independent of the box — unless the box is specifically listed for that greater weight. The 35-pound figure trips up candidates who confuse this with fan-rated box requirements. Know the numbers separately.

Question 3 — Grounding and Bonding

A commercial building has a concrete-encased electrode, ground rod, and building steel. What size grounding electrode conductor is required for 500 kcmil copper service entrance conductors?

• A. 2 AWG
• B. 1/0 AWG
• C. 3/0 AWG
• D. 4/0 AWG

Correct Answer: B — 1/0 AWG

Pull NEC Handbook, Table 250.66 (also IRC Table E3603.4). For 500 kcmil copper service entrance conductors, the table requires a 1/0 AWG copper grounding electrode conductor. Candidates who guess 3/0 or 4/0 are confusing the GEC with a supply-side bonding jumper or equipment grounding conductor — different tables, different rules.

How to Read Your Score

Passing is 74% — 45 out of 60 questions correct. On your first attempt, don't treat the score as a verdict. Treat it as a map.

If you score below 60%, you have significant gaps across multiple topics. Prioritize General Electrical Knowledge and Services, Feeders, and Branch Circuits first — those two topics together account for 28 of the 60 exam items. Getting those right puts you most of the way to passing.

If you score 65–73%, you're close but not there yet. Use your topic-by-topic breakdown to find where you're losing points. One bad topic can swing 4–5 questions, which is the difference between passing and retesting.

If you score at or just above 74% on a practice run, that's not a cushion — it's a warning. The real exam has variance, and a 75% practice score can become a 70% on test day. Aim to practice consistently above 80% before you sit.

Retake the full practice exam multiple times. The 481+ question pool means each attempt surfaces different questions, which is the closest thing to realistic exam preparation you can get without being in the test center.

Where Candidates Lose Points

Calculation shortcuts that skip steps. Voltage drop questions require the right formula, the right table value from Chapter 9, and correct unit handling. Candidates who round early or skip the conductor resistance step get the wrong number.

Wrong table for the job. Table 250.66 sizes the grounding electrode conductor. Table 250.122 sizes the equipment grounding conductor. Table 310.15(C)(1) applies temperature correction. Grabbing the wrong table is an instant wrong answer, and this exam tests all three.

The 125% rule applied wrong. Continuous load calculations require 125% applied to the load before sizing the OCPD or conductor. Candidates who apply it to the OCPD rating instead of the load get a wrong answer — and it's a different wrong answer, so it doesn't even look like a rounding error.

Cable type location rules. Where Type NM, AC, and MC cable can and cannot be installed is directly tested. The restrictions in NEC Handbook, Sections 334.10 and 334.12 are specific — "not in commercial" is not the whole answer.

Safety section guessing. Many candidates skip studying 29 CFR 1926. Four questions come from this topic, and they're straightforward if you've read them — but confusing if you haven't. Know who provides PPE per §1926.28(a) and what triggers first aid requirements per §1926.50(c).

Time management on calculations. With 13 items in General Electrical Knowledge alone, you'll face multiple multi-step problems early. Budget 3 minutes per question and move on if you're stuck.

Exam Quick Facts