North Carolina Intermediate Electrical Contractor (I)

11 questions | 11% of exam | Reference: NEC 2020 (NFPA 70)

Key Concepts

Grounded vs. Grounding vs. Bonding — Know the Difference - Grounded conductor: Current-carrying conductor intentionally connected to earth (neutral). Identified by white, gray, or three white/gray stripes (Art. 200). - Grounding electrode conductor (GEC): Connects the system to the grounding electrode (earth). Sized per NEC Table 250.66. - Equipment grounding conductor (EGC): Fault-current return path; connects equipment enclosures back to the source. Sized per NEC Table 250.122. - Bonding jumper: Ensures electrical continuity between metal parts; does not provide earth connection by itself.

Key Concepts

Article 240 Scope (240.1) - Parts I–VII cover overcurrent protection for systems ≤1000V nominal - Part VIII covers supervised industrial installations ≤1000V - Part IX covers systems >1000V nominal

Conductor Protection (240.4) Conductors must be protected per their ampacity as listed in 310.14, with specific exceptions for tap conductors and small conductors.

Tap Conductors (240.2) A tap conductor has overcurrent protection ahead of its point of supply that exceeds the value normally permitted for that conductor size. Tap rules (10-ft, 25-ft, transformer secondary) each have distinct length and sizing requirements.

Key Concepts

Article 300 — General Requirements - Wiring methods in Chapter 3 apply to 1000V nominal or less by default; permitted above 1000V only where specifically authorized (300.2(A)). - All conductors of the same circuit — including grounded conductors, EGCs, and bonding conductors — must be in the same raceway, cable, trench, or cable tray (300.3(B)). This prevents inductive heating from eddy currents. - Single conductors (Table 310.4(A)) may only be installed as part of a recognized wiring method (300.3(A)). - Paralleled conductors must keep all circuit conductors of each parallel set in the same raceway; each parallel set is treated independently (300.3(B)(1)).

NEC 2020 | 7 questions | 7% of exam

Key Concepts

Article 312 — Cabinets, Cutout Boxes, and Meter Socket Enclosures

Installation Position (312.3) - In noncombustible walls (concrete, tile, masonry): front edge of cabinet must not be set back more than 6 mm (¼ in.) from finished surface. - In combustible walls (wood framing): cabinet must be flush with or projecting from the finished surface — no setback permitted.

Repairing Noncombustible Surfaces (312.4) - Gaps or open spaces at the edge of a flush-type cabinet cover must be no greater than 3 mm (⅛ in.). Larger gaps must be repaired.

NEC 2020 | 9 Questions (9% of Exam)

Key Concepts

Service Entrance Conductors (Article 230) - Service conductors must be installed outside or be considered "outside" the building per NEC 230.6 if encased in 2" of concrete, or within a building vault. - 230.9: Service conductors installed as open conductors or multiconductor cables without an overall outer jacket must have clearance of at least 3 ft from windows, doors, porches, fire escapes, or similar openings. - 230.24: Overhead service conductor clearances — 10 ft minimum above finished grade at the service drop attachment point for residential, 12 ft over residential driveways, 18 ft over public streets/alleys/roads subject to truck traffic. - 230.28: Only one service mast is permitted per structure unless the building qualifies…

Key Concepts

Article 430 — Motors, Motor Circuits, and Controllers is the primary reference. Understand that motors require four separate levels of protection, each with its own sizing rules:

1. Branch-circuit conductors — sized at 125% of motor FLC (430.22)
2. Overload protection — sized to protect the motor windings (430.32)
3. Short-circuit and ground-fault protection — sized per Table 430.52 (fuses, breakers, etc.)
4. Disconnect — sized and located per 430.101–430.113

Full-Load Current (FLC): Always use NEC Tables 430.247–430.250, not the motor nameplate, for branch-circuit sizing calculations. Nameplate FLA is used for overload sizing only.

Key Concepts

Hazardous Location Classifications (Article 500) - Class I – Flammable gases or vapors (gas stations, commercial garages, bulk storage plants) - Class II – Combustible dusts - Class III – Ignitible fibers/flyings - Division 1 – Hazardous concentrations present under normal operating conditions - Division 2 – Hazardous concentrations present only under abnormal conditions (failure, accident) - All hazardous areas must be documented per 500.4; documentation available to anyone authorized to design, install, inspect, or maintain equipment

Commercial Garages & Gas Stations (Articles 511, 514) - Class I, Division 1 applies up to 18 inches above floor in repair garages (floor pits are Division 1 for entire pit) - Gas station dispensing areas: Class I, Division 1 within 18 inches of dispenser; Division 2…

11 Questions | 11% of Exam | Reference: NEC 2020 (NFPA 70)

Key Concepts

Branch Circuit Voltage Limitations (NEC 210.6) - Dwelling units, hotel guest rooms: max 120V between conductors for luminaires and cord-and-plug loads ≤1440 VA or less than ¼ hp - Circuits up to 277V to ground may supply electric-discharge luminaires, LED luminaires with integral drivers, mogul-base screw shell lampholders, and permanently connected utilization equipment - Circuits exceeding 277V to ground follow 210.6(D) and (E) restrictions

Multiwire Branch Circuits (NEC 210.4) - All conductors must originate from the same panelboard - Must have a simultaneous disconnect for all ungrounded conductors at the origin (210.4(B)) - Shall supply only line-to-neutral loads unless an exception applies (single utilization equipment, or all ungrounded conductors opened…

Key Concepts

Article 410 — Luminaires, Lampholders, and Lamps

• 410.6: All luminaires, lampholders, and retrofit kits must be listed. No exceptions.
• 410.7: Luminaires, lampholders, and retrofit kits cannot be reconditioned. Installing a listed retrofit kit in a luminaire per instructions does NOT make it "reconditioned."
• 410.5: No live parts normally exposed to contact. Exception: Cleat-type lampholders at least 8 ft above the floor may have exposed terminals.
• 410.8: Luminaire connections must be inspectable without disconnecting any wiring — unless connected via attachment plug and receptacle.
• 410.11: Luminaires must be constructed/installed so combustible material is not exposed to temperatures exceeding 90°C (194°F).
• 410.12: Lampholders over highly combustible material must be unswitched type and located at least 8 ft above the floor…

Key Concepts

Purpose of the NEC (Article 90.1) The NEC exists for the practical safeguarding of persons and property from hazards arising from the use of electricity. It is explicitly not a design specification or instruction manual for untrained persons. Compliance produces an installation that is "essentially free from hazard" — not necessarily efficient, convenient, or adequate for future expansion.

Scope of the NEC (Article 90.2) The Code covers installation and removal of electrical conductors, equipment, raceways, signaling/communications conductors, and optical fiber cables for: - Public and private premises (buildings, structures, mobile homes, RVs, floating buildings) - Yards, parking lots, carnivals, industrial substations - Conductors/equipment connecting to the electricity supply - Utility-owned office buildings, warehouses, garages, etc. that are not part of a generating plant, substation,…

Key Concepts

Electrical Contractors Licensing Law (GS Chapter 87, Article 4)

• The NC Electrical Contractors Licensing Board (NCELB) oversees licensing of electrical contractors in NC.
• License classes: Unlimited, Intermediate, Limited, and Restricted — each defines the scope of work permitted.
• Intermediate license permits work on systems up to 600 volts with no project cost limitation (distinguish from Limited, which has cost caps).
• Licenses must be renewed annually; working without a valid license is a violation.
• A qualifier (the licensed individual) must be bona fide employees of the contracting firm — the license is not transferable.
• Performing work beyond your license classification is a violation subject to civil penalties.