North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) Exam: Step-by-Step Study Guide
Preparing for the North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) exam is easier one step at a time. This guide starts with the key facts from the official bulletin, then covers the topics on the exam, the reference books, sample questions with answers, and a simple way to prepare. PSI gives the exam.
North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) Exam Overview
Start with the facts. Here's what the official bulletin says:
| Questions | 40 questions |
| Time limit | 3 hours |
| Passing score | 70% correct |
| Books in the exam room | Open book |
| Exam fee | $125 |
On exam day
- Questions are multiple choice with four suggested answers and only one correct answer.
- Two valid, non-expired signature-bearing IDs are required, one with a photograph, matching the name under which the candidate registered.
- Candidates should arrive 30 minutes before the appointment time.
- References must be softbound, spiral, or hardbound with no loose-leaf or partial books, must be candidate-supplied, may not be written in during the exam, and may not contain additional papers.
- Highlighting, underlining and handwritten notes made before the exam are allowed (pencil notes must be highlighted), and only permanent tabs may be used.
- Calculators are provided at the test center.
- Scratch paper, pencils and calculators are provided, while notes, briefcases, backpacks, hats, cell phones, pagers and children are prohibited in the examination area.
References you may bring
- National Electrical Code (2020 edition)
- National Fire Alarm Code (2013 edition)
- NASCLA Contractors Guide to Business, Law and Project Management: North Carolina Electrical Contractors' Edition (current edition)
Study references listed in the bulletin (not allowed in the exam room)
- Electrical Contractors Licensing Law (General Statutes Chapter 87, Article 4)
- The Board's Rules for the Implementation of the Electrical Contractors Licensing Law (Title 21, North Carolina Administrative Code, Chapter 18B)
Scheduling, changes and retakes
- Candidates register for the examination by calling PSI at (855) 746-8173 or online at https://test-takers.psiexams.com/ncbeec.
- Board approval is required before scheduling, and the approval allows one examination attempt within a 90-day authorization period.
- Candidates who miss the appointment or arrive after the examination start time lose their examination fees and may be refused admission.
- Results are given immediately at the test center, with a diagnostic report of strengths and weaknesses for candidates who do not pass.
- A candidate who fails must wait 3 months before retaking the same classification and must re-apply to the Board for each attempt.
- A passing candidate must complete a License Application with the Board to obtain and activate the license.
Source: NCBEEC Examination Information Handbook (North Carolina Board of Examiners of Electrical Contractors), July 2026. Check the bulletin before test day: fees and rules can change.
Topics on the North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) Exam
Next, the content. The official content outline has 11 topics:
| Topic | Questions | Share of the exam |
|---|---|---|
| Bonding and Grounding | 5 | 12% |
| Overcurrent Protection | 4 | 10% |
| Wiring Methods and Terminations | 3 | 8% |
| Boxes and Fittings | 4 | 10% |
| Service Entrance and Equipment | 4 | 10% |
| Motors and Control Wiring | 2 | 5% |
| Special Occupancies and Hazardous Locations | 1 | 2% |
| Load Calculations | 4 | 10% |
| Appliances, Equipment, and Lighting | 3 | 8% |
| General | 2 | 5% |
| Laws, Rules, Basic Business Practices, and Practical Applications | 8 | 20% |
Bonding and Grounding: Systems and equipment requiring grounding and ground-fault protection; Location of connection and required interconnections; Conductor identification and color coding; Bonding jumpers; Grounding electrode conductors; Equipment grounding conductors; Grounding electrodes; Low-voltage specifications.
Overcurrent Protection: Location in circuit; Sizing requirements; Circuit breakers; Plug and cartridge fuses; Enclosures and locations.
Wiring Methods and Terminations: Permitted applications and usages; Characteristics; Conduit and wireway fill; Permitted applications and usages; Characteristics; Protection from damage; Permitted usages and ampacity ratings; Characteristics.
Boxes and Fittings: General information; Sizing requirements.
Service Entrance and Equipment: Installation requirements; Service equipment; General sizing requirements.
Motors and Control Wiring: General information; Branch circuit and feeder ampacity; Overload protection; Short-circuit and ground-fault protection; Disconnects/controllers; Size; Type; Location.
Special Occupancies and Hazardous Locations: Mobile homes and mobile home parks; Swimming pools; Underwater lighting fixtures.
Load Calculations: Branch circuits; Total computed load; Conductor ampacity requirements; Low-voltage.
Appliances, Equipment, and Lighting: Air conditioners; Residential, commercial, and industrial equipment; Lighting fixtures; Space heating equipment and boilers; Transformers.
General: Definitions; Installation requirements.
Laws, Rules, Basic Business Practices, and Practical Applications: Electrical Contractors Licensing Law (General Statutes Chapter 87, Article 4); Board’s Rules for the Implementation of the Electrical Contractors Licensing Law (Title 21, North Carolina Administrative Code, Chapter 18B); NASCLA Contractors’ Guide to Business, Law and Project Management - North Carolina Electrical Edition; National Fire Alarm Code.
A Simple Plan to Prepare for the North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) Exam
Step one is the books. This is an open-book exam, so the references on the bulletin's list are what you'll work from, while you study and in the exam room. Get the editions the bulletin names.
Step two is learning your way around them. Go through each book's table of contents and index until you know where the major subjects are. You don't need to memorize the books. You need to find things in them.
Step three is marking them up. Highlight the sections you use most. The exam facts above list the bulletin's rules on tabs and markings, so follow them exactly.
Step four is timed practice. Our practice exams run on a clock, so you get used to the real exam's pace: about 4 minutes 30 seconds per question.
Along the way, give the most time to the biggest topics. Laws, Rules, Basic Business Practices, and Practical Applications and Bonding and Grounding make up 32% of the exam.
The last step is consistency. Keep practicing until you pass several practice exams in a row. That's the signal you're ready.
Reference Books for the North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) Exam
SP-SFD candidates must bring the 2020 National Electrical Code, the 2013 National Fire Alarm Code and the current NASCLA Contractors Guide, and the exam also covers the Licensing Law and the Board's Rules, which are study materials only.
Where to get them:
On Test Day
Go through the exam at a steady pace. On your first pass, answer the questions you know and bookmark the ones you don't. Every exam lets you come back to bookmarked questions.
On your second pass, return to your bookmarks one at a time. You have 3 hours for 40 questions, which is about 4 minutes 30 seconds per question, so keep moving and don't let one question hold you up. Before you finish, answer anything you skipped. A blank can't earn a point.
Study Tips
On an open-book exam, the winners aren't the smartest people in the room — they're the fastest at finding answers. Buy the required book, practice with it open, and tab and highlight each section the first time a question sends you there. Learn the index and table of contents until you can land on any topic in seconds. That speed is what separates a pass from a fail.
On an open-book exam, work through every question once: answer the ones you know and skip the ones you don't. Then go back to the ones you flagged. You can bookmark questions for later review, just like on our exams — and don't sink too much time into any single question. The clock is still running.
Give yourself at least three to six weeks. Use your exam's candidate bulletin as your roadmap for what's tested, and spend your time on finding-it-fast skills over rote memorization. In practice, aim for three clean passes at 80% or higher — setting your practice bar above the real cut score gives you a comfortable margin on test day.
Practicing against a ticking clock is the best way to beat exam-clock anxiety. Use these timed tests to build your pacing, so you learn to move steadily and never burn too long on a single question. By test day, the format feels routine.
Sample North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) Practice Questions
Here are a few questions from our practice question bank, each with its answer and reference.
Sample 1 — Boxes and Fittings
Question: Where nonmetallic-sheathed cable is used with single gang nonmetallic boxes not larger than a nominal size 57 mm x 100 mm (2¼ in. x 4 in.) mounted in walls or ceilings, the cable must be fastened within ______ of the box measured along the sheath to avoid requiring the cable to be secured to the box.
- A. 150 mm (6 in.)
- B. 200 mm (8 in.)
- C. 300 mm (12 in.)
- D. 450 mm (18 in.)
Correct Answer: B
Per NEC 314.17(B)(2), Exception, where nonmetallic-sheathed cable is used with single gang nonmetallic boxes not larger than 57 mm x 100 mm mounted in walls or ceilings, and where the cable is fastened within 200 mm (8 in.) of the box measured along the sheath, securing the cable to the box shall not be required.
Reference: NEC 2020 Section 314.17(B)(2) Exception
Sample 2 — Service Entrance and Equipment
Question: What is the minimum vertical clearance required for overhead service conductors over residential property and driveways where the voltage does not exceed 300 volts to ground?
- A. 12 feet
- B. 18 feet
- C. 10 feet
- D. 15 feet
Correct Answer: A
Per NEC 230.24(B)(2), overhead service conductors not exceeding 300 volts to ground shall have a minimum clearance of 3.7 m (12 ft) over residential property and driveways, and those commercial areas not subject to truck traffic.
Reference: NEC 2020 Section 230.24(B)(2)
Sample 3 — Load Calculations
Question: You are wiring a new dwelling unit and need to install receptacles in the kitchen to serve the countertop surfaces. According to the NEC, what type of protection is required for these receptacles?
- A. Arc-fault circuit-interrupter (AFCI) protection only
- B. Ground-fault circuit-interrupter (GFCI) protection only
- C. Both GFCI and AFCI protection
- D. No special protection is required for kitchen countertop receptacles
Correct Answer: C
Per NEC 210.8(A)(6), GFCI protection is required for kitchen receptacles installed to serve countertop surfaces in dwelling units. Per NEC 210.12(A), AFCI protection is also required for all 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets in dwelling unit kitchens.
Reference: NEC 2020 Section 210.8(A)(6) and 210.12(A)
Sample 4 — Wiring Methods and Terminations
Question: According to the NEC, what is the minimum clearance above finished grade for overhead spans of open conductors not exceeding 150 volts to ground, accessible to pedestrians only?
- A. 3.0 m (10 ft)
- B. 3.7 m (12 ft)
- C. 4.5 m (15 ft)
- D. 5.5 m (18 ft)
Correct Answer: A
Per NEC 225.18(1), overhead spans of open conductors not over 1000 volts nominal shall have a clearance of not less than 3.0 m (10 ft) above finished grade where the voltage does not exceed 150 volts to ground and accessible to pedestrians only.
Reference: NEC 2020 Section 225.18(1)
Practicing Online vs. With a PDF
A PDF lets you read questions at your own pace. The real exam runs on a clock. Our practice exams are timed and on a screen, so you practice finding answers with the clock running. Each attempt draws a new set of questions from our bank, and your results show your score by topic, so you always know what to study next.
Your Next Step
Take the free North Carolina Electrical Contractor - Single-Family Detached Residential Dwelling (SP-SFD) practice exam to see where you stand. Then study the topics that need the most attention, one at a time. For the official rules, read the exam bulletin, and see the licensing board's website.