New Jersey Electrical Contractor Exam
Practice at the real exam's pace
Every practice exam shows your time per question against the real exam's clock (2:33 here), and each topic lands in one of these:
What's on the exam
Questions per topic, out of 100Topics
General Electrical Knowledge
Key Concepts
Purpose and scope (Article 90). "The purpose of this Code is the practical safeguarding of persons and property from hazards arising from the use of electricity. This Code is not intended as a design specification or an instruction manual for untrained persons" — 90.2(A). Under 90.2(B) (Adequacy), compliance plus proper maintenance results in an installation "essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use."
Installations not covered — 90.2(D): ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles; installations underground in mines and self-propelled mobile surface mining machinery and its attendant trailing cable. Covered under…
Raceways and Enclosures
Key Concepts
Scope and voltage limits (Article 300) - Wiring methods specified in Chapter 3 shall be used for 1000 volts ac, 1500 volts dc, nominal, or less where not specifically limited elsewhere in Chapter 3 — NEC 2023: 300.2(A); NEC 2026: 300.4(A). - Metric designators and trade sizes are for identification purposes only and are not actual dimensions — Table 300.1(C).
Conductor grouping - All conductors of the same circuit, the grounded conductor, and all equipment grounding/bonding conductors shall be in the same raceway, conduit body, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord unless otherwise permitted — 300.3(B). Paralleled installations are one permitted exception; the same-raceway requirement applies separately to each portion of the paralleled…
Services, Feeders, and Branch Circuits
Key Concepts
Multiwire branch circuits (210.4) - All conductors of a multiwire branch circuit shall originate from the equipment containing the branch-circuit overcurrent protective device or protective devices, except as permitted in 300.3(B)(4) — 210.4(A). - Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates — 210.4(B). Per 240.15(B), either multipole circuit breakers or individual single-pole breakers with identified handle ties satisfy this. - Multiwire branch circuits shall supply only line-to-neutral loads, with Exception No. 1 (one utilization equipment) and Exception No. 2 (line-to-line loads where all ungrounded conductors are opened simultaneously by the branch-circuit overcurrent device) — 210.4(C).
Overcurrent Protection
Based on NEC 2023, Article 240 — Overcurrent Protection
Key Concepts
Scope and reconditioning - Parts I through VII of Article 240 give general requirements for overcurrent protection and OCPDs not more than 1000 volts, nominal. Part VIII covers supervised industrial installations at not more than 1000 volts, nominal (240.1). - Equipment that shall not be reconditioned includes equipment providing ground-fault protection of equipment, GFCIs, low-voltage fuseholders and low-voltage nonrenewable fuses, molded-case circuit breakers, and low-voltage power circuit breaker electronic trip units (240.2(A)). Reconditioning is permitted for low-voltage power circuit breakers and electromechanical protective relays and current transformers (240.2(B)).
Conductors and Cables
New Jersey Electrical Contractor Exam | 9 questions (9%)
Key Concepts
Flexible cord types and ratings (Table 400.4) - Flexible cords and flexible cables shall conform to the description in Table 400.4; use of types other than those in the table requires permission by the authority having jurisdiction (400.4). - Type S hard service cord is rated 600 volts. Type SPT-1 is a thermoplastic parallel cord for pendant or portable use in dry locations, "not hard usage" — unlike S, SO (extra-hard usage) and SJ (hard usage). - Type G portable power cable is rated 2000 volts; conductors 12 AWG through 500 kcmil (Table 400.4). 2000 volts is the top voltage shown in Table 400.4. - Note 11: Types…
Grounding and Bonding
Key Concepts
Performance requirements (Part I) - The earth shall not be considered an effective ground-fault current path; equipment and wiring must create a low-impedance circuit facilitating operation of the overcurrent device (250.4(A)(5)). - Objectionable current: permitted alterations include discontinuing one or more but not all grounding/bonding connections, changing their locations, interrupting continuity of the conductor causing the current, or taking other remedial and approved action (250.6(B)). - Permitted connection methods include listed pressure connectors, terminal bars, exothermic welding, and machine screw-type fasteners engaging not less than two threads (250.8(A)). Devices that depend solely on solder shall not be used (250.8(B)). - Nonconductive coatings (paint, lacquer, enamel) must be removed from threads and contact surfaces, or fittings designed to…
Equipment for General Use
New Jersey Electrical Contractor Exam — 9 questions (9% of exam)
Key Concepts
Switches (Article 404) - Switches and circuit breakers used as switches shall be installed so the center of the grip of the operating handle, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform — 404.8(A). Exceptions exist for busway installations, devices adjacent to the equipment they supply, and hookstick-operable isolating switches. - Switches or circuit breakers shall not disconnect the grounded conductor, except where all circuit conductors are disconnected simultaneously, or where arranged so the grounded conductor cannot be disconnected until all ungrounded conductors have been disconnected — 404.2(B). - The grounded circuit conductor…
Special Occupancies
Key Concepts
Documentation (500.4). Areas designated as hazardous (classified) locations or determined to be unclassified shall be documented on an area classification drawing and other associated documentation, available to the AHJ and to those authorized to design, install, inspect, maintain, or operate electrical equipment at the location. Parallel requirements appear in 505.4 (Zones 0, 1, 2) and 506.4 (Zones 20, 21, 22).
Class definitions (500.5). - Class I (500.5(B)) — flammable gases, flammable liquid–produced vapors, or combustible liquid–produced vapors present in air in quantities sufficient to produce explosive or ignitible mixtures. - Class I, Division 1 (500.5(B)(1)) — ignitible concentrations can exist under normal operating conditions; or might exist frequently from repair/maintenance or leakage; or could be released by…
Special Equipment and Conditions
NJ Electrical Contractor Exam
Key Concepts
Electric Signs and Outline Lighting (Art. 600) - Branch circuits supplying neon tubing installations shall not be rated in excess of 30 amperes — 600.5(C)(1). Branch circuits supplying all other signs and outline lighting systems shall be rated not to exceed 20 amperes — 600.5(C)(2). Sign circuits are considered continuous loads — 600.5(C). - The required sign outlet at each tenant entrance is supplied by a branch circuit rated at least 20 amperes that supplies no other load — 600.5(A). - Equipment grounding conductor size shall be in accordance with 250.122 — 600.7(A)(2). - Enclosure metal: sheet steel at least 0.41 mm (0.016 in.) thick; sheet copper or aluminum **at least 0.51 mm…
Motors and Controls
Key Concepts
- Which current do you use? Per 430.6(A)(1), the values in Table 430.247, 430.248, 430.249, and 430.250 are used instead of the nameplate current to determine conductor ampacity, current ratings of switches, and branch-circuit short-circuit and ground-fault (SC/GF) protection. Per 430.6(A)(2), the nameplate current rating is used for separate motor overload protection. Single-phase AC FLCs come from Table 430.248; three-phase AC FLCs come from Table 430.250.
- Branch-circuit conductors (430.22): a single motor in a continuous duty application requires conductors with an ampacity not less than 125% of the motor FLC as determined by 430.6(A)(1).
- Special connections (430.22(C), (D)): for a wye-start, delta-run motor, conductors between controller and motor shall be not less than 72% of…
Low Voltage and Communications Circuits
Key Concepts
Outside and entering buildings (Article 800, Part II) - Overhead communications wires/cables and CATV-type coaxial cables shall have a vertical clearance of not less than 2.5 m (8 ft) from all points of roofs above which they pass — 800.44(B). Exceptions: auxiliary buildings (garages and the like); not less than 450 mm (18 in.) above only the roof overhang if not more than 1.2 m (4 ft) of service-drop passes over the overhang and it terminates at a through- or above-the-roof raceway or approved support; not less than 900 mm (3 ft) where the roof slope is not less than 100 mm in 300 mm (4 in. in 12 in.). - Supply service drops of 0–750 volts…
Safety
Key Concepts
Equipment approval, listing, identification - Equipment that is listed, labeled, or both, or identified for a use shall be installed and used in accordance with any instructions included in the listing, labeling, or identification — NEC 2023, 110.3(B). Instructions may be printed, a QR code, or an internet address. - Among the considerations in judging equipment, cybersecurity — the ability to withstand unauthorized updates and malicious attacks while continuing to perform its intended safety functionality — applies to network-connected life safety equipment — 110.3(A). - Listing/certification is performed by recognized qualified electrical testing laboratories — 110.3(C).