Exam Cheat Sheet · Quick Reference

New Jersey Electrical Contractor Exam

New Jersey  ·  PSI Services Contractor

Verified, not estimated. Every figure below is drawn from the official exam structure we maintain — question counts, passing standard and topic weighting. Practice questions are grounded in the source law with statute citations. We omit any figure we can't verify rather than guess at it.
Total questions
100
Passing score
70%
Exam time
255 min
Administered by
PSI Services Contractor
Format
Reference materials allowed

New Jersey State Portion 100 questions

General Electrical Knowledge 10 Q · 10%
Raceways and Enclosures 10 Q · 10%
Services, Feeders, and Branch Circuits 10 Q · 10%
Overcurrent Protection 5 Q · 5%
Conductors and Cables 9 Q · 9%
Grounding and Bonding 16 Q · 16%
Equipment for General Use 9 Q · 9%
Special Occupancies 5 Q · 5%
Special Equipment and Conditions 5 Q · 5%
Motors and Controls 12 Q · 12%
Low Voltage and Communications Circuits 6 Q · 6%
Safety 3 Q · 3%
Working space clearances and dimensions around electrical equipmentGuarding of live parts against accidental contactArc-flash hazard warning labels and markingsGround-fault circuit-interrupter (GFCI) protection for temporary installationsEquipment approval, listing, labeling, and identification requirementsDisconnecting means identification and lockout provisionsEnclosure type selection for environmental conditionsOvercurrent protection and interrupting ratings for temporary wiring

Key Distinctions

Motor branch-circuit conductor sizing (430.22)vsMotor disconnecting means sizing (430.110(A))

Branch-circuit conductors must be at least 125% of the motor's table full-load current, while the disconnect must be rated at least 115% of that same full-load current.

NEC 2023 Table 430.248, Section 430.22
Table 430.248vsTable 430.250

Table 430.248 gives full-load currents for single-phase AC motors, while Table 430.250 gives full-load currents for three-phase motors; per 430.6(A)(1) both are used instead of nameplate values for conductor, disconnect and OCPD sizing.

NEC 2023 Section 430.6(A)(1) and Table 430.248
Motor nameplate full-load amperesvsTable full-load current (FLC)

Overload protection per 430.32(A)(1) is based on the motor NAMEPLATE current, while conductor, feeder, disconnect and branch-circuit short-circuit/ground-fault sizing use the table FLC per 430.6(A)(1).

NEC 2023 Section 430.32(A)(1)
Time-delay (dual-element) fuse, Table 430.52vsInverse-time circuit breaker, Table 430.52

For an AC squirrel cage (Design B) motor the time-delay fuse is rated at 175% of FLC while the inverse-time breaker is rated at a maximum of 250% of FLC; in both cases 430.52(C)(1) permits going to the next higher standard size of 240.6(A).

NEC 2023 Table 430.250, Table 430.52, Section 240.6(A)
Conductor ampacity from Table 310.16vsMaximum overcurrent protection per 240.4(D)

A 12 AWG THWN copper conductor has a Table 310.16 ampacity of 25 amperes at 30°C (75°C column), whereas the commonly cited 20 amperes is the maximum overcurrent protection allowed for 12 AWG, not its ampacity.

NEC 2023 Table 310.16
Neon sign branch circuits (600.5(C)(1))vsOther sign and outline lighting branch circuits (600.5(C)(2))

Branch circuits supplying neon tubing installations shall not be rated in excess of 30 amperes, while all other sign and outline lighting branch circuits are limited to 20 amperes.

NEC 2023 Section 600.5(C)(1)
Straight pull box sizing (314.28(A)(1))vsAngle pull box sizing (314.28(A)(2))

For straight pulls the minimum length is 8 times the trade diameter of the largest raceway, while for angle pulls the minimum distance is 6 times the largest conduit trade diameter plus the sum of the trade diameters of the other conduits on the same wall.

NEC 2023 Section 314.28(A)(1)
EGC in a flexible cord (400.23 / 250.122(E))vsEGC per Table 250.122

Flexible cord EGCs may be sized per 400.23/Table 400.4 (as small as 18 AWG copper for certain cord types), and per 250.122(E), where the largest circuit conductor is 10 AWG or smaller, the cord EGC shall not be smaller than 18 AWG copper and not smaller than the circuit conductors, instead of following Table 250.122, which otherwise requires a 14 AWG minimum.

NEC 2023 Section 400.23
Emergency power source duration (700.12(C))vsStorage batteries/UPS for emergency illumination (700.12(C)(4))

The general emergency power source duration shall in no case be less than 2 hours, while storage batteries and UPS supplying emergency illumination must maintain the load for a minimum of 1½ hours without voltage falling below 87½ percent of nominal.

NEC 2023 Section 700.12(C)
NEC Chapters 1, 2, 3 and 4vsNEC Chapters 5, 6, 7 and 8

Chapters 1 through 4 apply generally to all electrical installations, Chapters 5-7 apply to special occupancies, equipment or conditions and may supplement or modify Chapters 1 through 7, and Chapter 8 (communications systems) is not subject to Chapters 1-7 unless specifically referenced in Chapter 8.

NEC 2023 Section 90.3
Main/system bonding jumper screw identification (250.28(B))vsRed finish

Where the main or system bonding jumper is a screw only, the screw must be identified with a GREEN finish visible with the screw installed — not red.

NEC 2023 Section 250.28(B)
Office furnishing interconnection cord (605.5)vsOffice furnishing lighting accessory cord (605.6(B)(1))

Interconnection cord between office furnishings shall not exceed 600 mm (2 ft), while a cord-and-plug connection for lighting equipment shall not exceed 2.7 m (9 ft).

NEC 2023 Section 605.5

Key Terms

Chapter 8 (NEC 90.3) NEC 2023 Section 90.3
The chapter covering communications systems, which is not subject to the requirements of Chapters 1 through 7 except where specifically referenced in Chapter 8.
NEC arrangement (90.3) NEC 2023 Section 90.3
The Code consists of the introduction plus nine chapters, with Chapters 1-4 applying generally, Chapters 5-7 to special occupancies/equipment/conditions, Chapter 8 to communications, and Chapter 9 consisting of tables applicable as referenced.
SI units preference (90.9(B)) NEC 2023 Section 90.9(B)
Metric (SI) units are given preference by appearing first with inch-pound units immediately following in parentheses, although 90.9(D) permits compliance with either system.
Multiwire branch circuit disconnect (210.4(B)) NEC 2023 Section 210.4(B)
Each multiwire branch circuit must have a means to simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates, which may be a multipole breaker or individual single-pole breakers with identified handle ties per 240.15(B); it is not required at the motor controller.
AFCI protection in dwelling bedrooms (210.12(B)) NEC 2023 Section 210.12(B)
All 120-volt, single-phase, 10-, 15- and 20-ampere branch circuits supplying outlets or devices in dwelling unit bedrooms must be protected by any of the means described in 210.12(A)(1) through (A)(6).
AFCI extension exception (210.12(E)) NEC 2023 Section 210.12(E)
AFCI protection is not required where an extension of existing branch-circuit conductors is not more than 1.8 m (6 ft) and adds no outlets or devices other than splicing devices.
Small-appliance branch circuits (210.11(C)(1)) NEC 2023 Section 210.11(C)(1)
In dwelling units, two or more 20-ampere small-appliance branch circuits shall be provided for all receptacle outlets specified by 210.52(B).
Service disconnecting means (230.71) NEC 2023 Section 230.71(B)
Each service shall have only one disconnecting means unless 230.71(B) applies, which permits two to six service disconnects — a maximum of six.
One-family dwelling service rating (230.79(C)) NEC 2023 Section 230.79(C)
Service equipment for a one-family dwelling shall have a rating of not less than 100 amperes, 3-wire.
Grounding electrode conductor (Table 250.66) NEC 2023 Table 250.66
The conductor sized from Table 250.66 by service-entrance conductor size — for example, 2 AWG copper for 4/0 AWG copper service conductors and 1/0 AWG copper for copper service conductors over 350 through 600 kcmil (500 kcmil).
Supplemental electrode bonding jumper (250.53(E)) NEC 2023 Section 250.53(E)
Where the supplemental electrode is a rod, pipe, or plate electrode, the portion of the bonding jumper that is the sole connection to it is not required to be larger than 6 AWG copper or 4 AWG aluminum/copper-clad aluminum.
Flexible cord splice rule (400.13) NEC 2023 Section 400.13
Flexible cords shall be used only in continuous lengths without splice or tap, except that hard-service and junior hard-service cords 14 AWG and larger may be repaired if spliced per 110.14(B) and the splice retains the cord's insulation, outer sheath and usage characteristics.
Autoignition temperature (500.8(B)(1)) NEC 2023 Section 500.8(B)(1)
In Class I locations, equipment shall not have any exposed surface operating at a temperature in excess of the autoignition temperature of the specific gas or vapor present.
Thread engagement for explosionproof equipment (500.8(E)(1)) NEC 2023 Section 500.8(E)(1)
NPT-threaded entries into explosionproof equipment shall be made up with at least five threads fully engaged, with an exception allowing at least four and one-half threads for listed explosionproof equipment with factory-threaded NPT entries.
Emergency lighting availability (700.12) NEC 2023 Section 700.12
Emergency lighting shall be available within the time required for the application but not to exceed 10 seconds after failure of the normal supply.
Type BLP cable (800.179(A)) NEC 2023 Section 800.179(A)
Network-powered broadband communications low-power plenum cable, listed as suitable for ducts, plenums and other environmental air spaces with adequate fire-resistant and low-smoke-producing characteristics (BLR is low-power riser, BMR medium-power riser, BLX limited-use).

Formulas to Know

Motor branch-circuit conductor minimum ampacity (430.22)Table FLC (430.248 single-phase / 430.250 three-phase) × 125%; e.g., 52A × 1.25 = 65A for a 40 HP, 460V 3-phase motor, and 88A × 1.25 = 110A for a 30 HP, 208V 3-phase motor (select conductor from Table 310.16, 75°C column)
Motor feeder minimum conductor ampacity (430.24)125% of the largest motor FLC + 100% of all other motor FLCs; e.g., (34A × 125%) + 21A = 63.5A, and (52A × 1.25) + 34A = 99A
Motor disconnecting means minimum rating (430.110(A))Table FLC × 115%; e.g., 65A × 1.15 = 74.8A (50 HP, 460V) and 52A × 1.15 = 59.8A (40 HP, 460V)
Maximum motor overload protection (430.32(A)(1), service factor 1.15 or greater)Nameplate full-load amperes × 125% (not table FLC); e.g., 82A × 1.25 = 102.5A and 26A × 1.25 = 32.5A
Motor branch-circuit short-circuit/ground-fault protection (Table 430.52 with 240.6(A))Time-delay (dual-element) fuse = 175% of table FLC (52A × 1.75 = 91A → next standard 100A; 59.4A × 1.75 = 103.95A → 110A); inverse-time circuit breaker for Design B squirrel cage = 250% of FLC (34A × 2.5 = 85A → 90A; 30.8A × 2.5 = 77A → 80A); next higher standard size permitted per 430.52(C)(1)
Continuous load conductor sizingBranch circuit (210.19(A)(1)): noncontinuous load + 125% of the continuous load; feeder (215.4(A)(1)(a) / 2023: 215.2(A)(1)(a)): continuous load × 125%, e.g., 30A × 1.25 = 37.5A added to the motor portion
Three-phase current from kVAI = kVA × 1,000 / (E × 1.732); e.g., 75,000 / (208 × 1.732) = 208A, and 150,000 / (480 × 1.732) = 180.4A (next standard OCPD per 240.6(A) = 200A)
Generator output feeder conductors (445.13)Ampacity not less than 115% of the generator nameplate current; e.g., 180.4A × 1.15 = 207.5A → 4/0 AWG copper THWN (230A at 75°C), since 3/0 AWG at 200A is insufficient
Pull and junction box dimensions (314.28)Straight pull: length ≥ 8 × trade diameter of the largest raceway (8 × 3" = 24 in.); Angle pull: distance to opposite wall ≥ 6 × largest conduit trade diameter + sum of trade diameters of other conduits on the same wall (6 × 3" + 2" + 1½" = 21.5 in.)
Outlet box fill volume (314.16(B), Table 314.16(B)(4) / 2023 Table 314.16(B)(1))12 AWG = 2.25 cu in. and 14 AWG = 2.00 cu in. each for conductors; up to four equipment grounding conductors = one volume allowance based on the largest EGC; each device yoke = 2 × the volume of the largest conductor connected to it
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