Exam Cheat Sheet · Quick Reference
ICC R17 Journeyman Electrician Exam (2023 NEC)
National · Pearson Vue
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
80
Passing score
70%
Exam time
240 min
Administered by
Pearson Vue
Format
Reference materials allowed
National State Portion 80 questions
General Knowledge
5 Q · 6%
Electrical Theory and General Electrical Load CalculationsCode Definitions and TermsPlan ReadingAC Circuit Properties: Impedance, Reactance, and InductancePower Factor, Power Factor Correction, and CapacitorsNEC Purpose, Scope, and Code Arrangement (Article 90)Series, Parallel, and Combination Circuit AnalysisElectrical Distribution Systems and Wiring DiagramsField Terms vs. NEC Terms and Electrical SymbolsApplied Mathematics for Electricians: Fractions, Equations, and TrigonometryUnits of Measurement and Conversion
Services and Service Equipment
9 Q · 11%
Services and Fault CurrentService Load CalculationsService Equipment & Service ConductorsTransformersSystem Grounding and BondingTemporary Service WiringService disconnecting means requirements and ratingsOvercurrent protection for services and ground-fault protection of equipmentOverhead and underground service conductor installation requirementsSurge-protective devices (SPDs) and surge arresters at service equipmentGrounding electrode system types and installationEquipment grounding conductor types, sizing, and identification
+2 more
Feeders
3 Q · 4%
Load CalculationsEquipment GroundingFeeder conductor sizing (minimum ampacity and continuous vs. noncontinuous loads)Overcurrent protection for feedersFeeder neutral conductor sizingDemand factors for dwelling and non-dwelling loadsOutside feeder installation requirements (clearances, supports, and wiring methods)Feeder disconnecting means requirements (rating, location, and number)Surge-protective device requirements for feedersGround-fault protection of equipment for feeder disconnects
Branch Circuits and Conductors
15 Q · 19%
Branch Circuit CalculationOvercurrent ProtectionConductorsRequired Outlets & GFCI/AFCI ProtectionEquipment GroundingVoltage Drop Calculations for Branch CircuitsConductor Ampacity Correction and Adjustment FactorsConductor Insulation Types and ApplicationsMultiwire Branch Circuit RequirementsBranch Circuit Voltage LimitationsGrounded Conductor Identification and Use
Wiring Methods and Materials
21 Q · 26%
Raceway InstallationsUnderground Wiring MethodsBoxes and EnclosuresCabinets, Panelboards, & SwitchboardsClearance and GuardingFlexible Cords and CablesCable Wiring Methods (NM, AC, MC, MI, SE, UF, TC, ITC, and specialty types) — Uses Permitted and Not PermittedConduit Bending Calculations and TechniquesConductor Fill and Conduit Sizing (Chapter 9 Tables)General Wiring Requirements — Conductor Grouping, Protection from Physical Damage, and Structural PenetrationsCable Tray Systems — Installation, Fill, and Wiring Methods PermittedSpecial Raceway Systems — Busways, Wireways, Auxiliary Gutters, and Surface Raceways
+2 more
Equipment and Devices
10 Q · 12%
LuminairesReceptacles, Switches and Other DevicesAppliances and Other EquipmentOther Utilization EquipmentHeating and Cooling EquipmentFixture Wire Types, Ampacity, and Installation RequirementsLighting Track Installation, Construction, and RestrictionsLow-Voltage Lighting System Requirements and Voltage LimitationsNEMA Receptacle and Attachment Plug ConfigurationsDisconnecting Means for Fixed Electric Space-Heating EquipmentBranch-Circuit and Overcurrent Protection for Air-Conditioning and Refrigerating EquipmentGround-Fault Protection for Outdoor Deicing, Snow-Melting, and Pipeline Heating Equipment
Control Devices
3 Q · 4%
Switches, Disconnects and ControllersMotor controller ratings, markings, and horsepower requirementsMotor control circuit overcurrent protection and wiring methodsMotor disconnecting means types, location, and current ratingsMotor overload protection devices and settingsStop-start stations, jogging circuits, and hand-off-automatic control schemesIndustrial control panel overcurrent protection, short-circuit current rating, and markingClass 1 power-limited remote-control and signaling circuit requirementsMotor control center installation, overcurrent protection, and grounding
Motors and Generators
5 Q · 6%
MotorsGeneratorsMotor branch-circuit conductor sizing (125% rule and special motor types)Motor overload protection selection and trip current percentagesMotor branch-circuit short-circuit and ground-fault protective device ratings (Table 430.52)Motor disconnecting means requirements and locationMotor controllers — ratings, types, and marking requirementsMotor control centers — overcurrent protection, grounding, and busbar arrangementsGenerator installation requirements — overcurrent protection, conductor ampacity, and disconnecting meansPhase converters and capacitors in motor circuits
Special Occupancies, Equipment, and Conditions
9 Q · 11%
Special OccupanciesSwimming Pools and Similar InstallationsMobile Home and RV ParksData Processing EquipmentMiscellaneous Special EquipmentEmergency SystemsSignaling and Fire Alarm SystemsHazardous Location Classification (Classes, Divisions, and Zones)Wiring Methods and Equipment in Hazardous LocationsHealth Care Facility Essential Electrical Systems and Patient Care SpacesSolar PV, Wind, and Fuel Cell System Wiring and Disconnecting MeansEnergy Storage Systems and Interconnected Power Production Sources
+3 more
Key Distinctions
Boxes in damp locationsvsBoxes in wet locations
Per NEC 314.15, boxes, conduit bodies, outlet box hoods, and fittings in wet locations shall be listed for use in wet locations, while in damp locations they only need to be placed or equipped to prevent moisture from entering or accumulating.
NEC 2023 Section 314.15Straight pull box sizing (conductors 4 AWG or larger)vsAngle or U pull box sizing (conductors 4 AWG or larger)
Per 314.28(A)(1) a straight pull box length shall not be less than eight times the trade size of the largest raceway, while per 314.28(A)(2) for angle/U pulls or splices the distance from each raceway entry to the opposite wall shall not be less than six times the trade size of the largest raceway, increased by the sum of the diameters of the other raceway entries in the same row on the same wall.
NEC 2023 Section 314.28(A)(1)Direct-buried cables/conductors, all locations not specified (Table 300.5(A))vsRigid metal conduit or IMC, all locations not specified (Table 300.5(A))
Direct-buried cables or conductors require a minimum cover of 600 mm (24 in.) while RMC or IMC requires a minimum cover of only 150 mm (6 in.) in those same unspecified locations.
NEC 2023 Table 300.5(A)RMC in 'all locations not specified' (6 in. cover)vsRMC under a one- and two-family dwelling driveway (18 in. cover)
The 150 mm (6 in.) RMC figure applies only where the location is not specified in Table 300.5, but a one- and two-family dwelling driveway/outdoor parking area used only for dwelling purposes IS a specified row requiring 450 mm (18 in.); general streets, highways, roads, alleys, driveways and parking lots require 600 mm (24 in.) for all wiring methods.
NEC 2023 Table 300.5(A)Grounded (neutral) conductor color, 120/240-V single-phase 3-wirevsUngrounded conductor colors, 120/240-V single-phase 3-wire
The grounded neutral is white or gray (per NEC 200.6(A)), while the two ungrounded conductors are black (line one) and red (line two).
Ugly's Electrical References, 2023 ed., Common Electrical Distribution Systems, Page 13 (2020 ed.: Common Electrical Distribution Systems)Minimum overhead service conductor — coppervsMinimum overhead service conductor — aluminum or copper-clad aluminum
Per 230.23(B), overhead service conductors shall not be smaller than 8 AWG copper, but not smaller than 6 AWG for aluminum or copper-clad aluminum.
NEC 2023 Section 230.23(B)Motor control circuit tapped from the load side of the motor branch-circuit short-circuit and ground-fault protective devicevsMotor control circuit supplied from a separate source
Per 430.72(A), a tapped control circuit is protected per 430.72, while a control circuit other than such a tapped circuit shall be protected against overcurrent in accordance with 724.43 (Class 1 power-limited rules) or the notes to Chapter 9 Table 11(A) and Table 11(B), as applicable.
NEC 2023 Section 430.72(A)Elevator raceway conductor fill (Article 620.33)vsGeneral wiring raceway fill (Chapter 9, Table 1)
For elevator installations the sum of the cross-sectional area of the individual conductors shall not exceed 50 percent of the interior cross-sectional area of the raceway, a special provision that differs from the standard Chapter 9, Table 1 fill percentages used in general wiring.
NEC 2023 Section 620.33Hermetic motor-compressor branch-circuit conductors (440.32)vsHermetic motor-compressor branch-circuit short-circuit/ground-fault OCPD (440.22(A))
Conductors require an ampacity of not less than 125% of the rated-load current (a minimum), while the protective device is permitted at not more than 175% of the RLA (a maximum), increasable to not more than 225% of RLA only if the device cannot carry the starting current.
NEC 2023 Section 440.32 and 440.22(A)Motor branch-circuit conductor sizing (430.22)vsMotor feeder conductor sizing (430.24)
Branch-circuit conductors must be not less than 125% of that motor's full-load current, while feeder conductors must be not less than 125% of the largest motor's FLC plus the sum of the full-load currents of the other motors.
NEC 2023 Section 430.22, Table 430.248Box-fill volume allowance, 14 AWG conductorvsBox-fill volume allowance, 12 AWG conductor
Table 314.16(B)(1) requires 32.8 cm³ (2.00 in.³) per 14 AWG conductor versus 36.9 cm³ (2.25 in.³) per 12 AWG conductor.
NEC 2023 Table 314.16(B)(1)Cables/raceways through bored holes or parallel to framing members (300.4(A)(1), 300.4(D))vsCables/raceways laid in notches in wood members (300.4(A)(2))
Bored holes and parallel runs must keep the edge/nearest outside surface not less than 32 mm (1 1/4 in.) from the edge of the wood or framing member (steel plate or sleeve required if that distance cannot be maintained), while cables or raceways in notches must always be covered by a steel plate at least 1.6 mm (1/16 in.) thick of appropriate length and width.
NEC 2023 Section 300.4(A)(1)Key Terms
Authority Having Jurisdiction (AHJ) NEC 2023 Section 90.4(B)
Per Article 90.4, the authority having jurisdiction for enforcement of the Code has the responsibility for making interpretations of the rules, deciding on approval of equipment and materials, and granting special permission contemplated in the rules.
NEC scope exclusions (Article 90.2) NEC 2023 Section 90.2(D)
The Code does not cover installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles.
Code arrangement (NEC 90.3) NEC 2023 Section 90.3
The Code is divided into an introduction and nine chapters: Chapters 1–4 apply generally, Chapters 5–7 apply to special conditions, Chapter 8 covers communications, and Chapter 9 consists of tables.
Service disconnecting means rating, one-family dwelling (230.79(C)) NEC 2023 Section 230.79(C)
For a one-family dwelling the service disconnecting means shall have a rating of not less than 100 amperes, 3-wire.
Optional calculation for a dwelling unit (220.82(A)) NEC 2023 Section 220.82(A)
The optional calculation applies to a dwelling unit whose total connected load is served by a single 120/240-volt or 208Y/120-volt set of 3-wire service or feeder conductors with an ampacity of 100 or greater.
Free conductor length at boxes (300.14) NEC 2023 Section 300.14
At least 150 mm (6 in.) of free conductor, measured from where it emerges from its raceway or cable sheath in the box, shall be left at each outlet, junction, and switch point for splices or connection of luminaires or devices.
Stranded conductors in raceways (310.3(C)) NEC 2023 Section 310.3(C)
Where installed in raceways, conductors 8 AWG and larger shall be stranded unless specifically permitted or required elsewhere in the Code to be solid.
Basis of Table 310.16 ampacities NEC 2023 Section 310.16
The ampacities in Table 310.16 are based on a 30°C (86°F) ambient temperature; other ambients require correction factors from Table 310.15(B)(1)(1).
Ampacity adjustment factor (Table 310.15(C)(1)) NEC 2023 Table 310.15(C)(1)
Where more than three current-carrying conductors are in a raceway or cable, ampacity table values are adjusted to 80% for 4–6 conductors, 70% for 7–9 conductors, and 50% for 10–20 conductors.
Type THHN maximum operating temperature NEC 2023 Table 310.4(1)
Type THHN conductors have a maximum operating temperature of 90°C (194°F) in dry and damp locations.
Main bonding jumper / system bonding jumper screw (250.28(B)) NEC 2023 Section 250.28(B)
If a main bonding jumper or system bonding jumper is a screw only, the screw shall be identified with a green finish that is visible with the screw installed.
PV array boundary for rapid shutdown (690.12(B)) NEC 2023 Section 690.12(B)
The array boundary is 305 mm (1 ft) from the array in all directions; controlled conductors outside this boundary and more than 1 m (3 ft) from the array, or inside a building, shall be limited to not more than 30 volts within 30 seconds of rapid shutdown initiation.
Elevator feeder demand factors (Table 620.14) NEC 2023 Table 620.14
Demand factors applied to a feeder serving multiple elevators, based on a 50 percent duty cycle: 1 elevator = 1.00, 2 = 0.95, 3 = 0.90, 4 = 0.85, 5 = 0.82, 6 = 0.79, 7 = 0.77, 8 = 0.75, 9 = 0.73, 10 or more = 0.72.
Feeder tap not over 10 ft (240.21(B)(1)) NEC 2023 Section 240.21(B)(1)
For taps not over 10 ft long, if the tap conductors leave the enclosure or vault where the tap is made, their ampacity must be not less than one-tenth of the rating of the overcurrent device protecting the feeder, and they must also meet the other 240.21(B)(1) requirements including being not less than the combined calculated loads.
Raceways in wet locations above grade (300.9) NEC 2023 Section 300.9
Where raceways are installed in wet locations above grade, the interior of those raceways shall be considered a wet location, and insulated conductors and cables installed in them shall comply with 310.10(C).
Conductors of the same circuit (300.3(B)) NEC 2023 Section 300.3(B)
All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding and bonding conductors shall be contained within the same raceway, conduit body, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord unless otherwise permitted.
Formulas to Know
Ohm's Law and power formulas
I = W ÷ E (1500 W ÷ 120 V = 12.5 A); R = E ÷ I (240 V ÷ 8 A = 30 ohms); E = I × R (10 A × 12 ohms = 120 V); P = E × I; P = E² ÷ R (240² ÷ 20 = 2880 W)Three-phase calculations (multiplier 1.73 = √3)
kW = (E × I × PF × 1.73) ÷ 1000 — example: (460 × 52 × 0.80 × 1.73) ÷ 1000 ≈ 33 kW; amperes when HP known: I = (HP × 746) ÷ (E × %EFF × PF × 1.73)Minimum feeder / service-entrance conductor ampacity with continuous loads
Ampacity not less than noncontinuous load + 125% of continuous load (215.2(A)(1); 230.42(A)(1)) — examples: 80 A + (60 A × 1.25) = 155 A; (100 A × 1.25) + 30 A = 155 AMinimum branch-circuit OCPD rating for continuous load (210.20(A))
OCPD rating not less than 125% of the continuous load — example: 16 A × 1.25 = 20 A minimumMotor branch-circuit conductor ampacity (430.22)
Not less than 125% of motor full-load current from Table 430.248/430.250 — examples: 5-HP 230 V 1-phase, FLC 28 A × 1.25 = 35 A; 50-HP 480 V 3-phase, FLC 65 A × 1.25 = 81.25 AMotor feeder conductor ampacity (430.24)
125% of the largest motor FLC + sum of the FLCs of the other motors — example: (1.25 × 65 A) + 40 A = 121.25 A for a 50-HP and 30-HP 480 V 3-phase pairNontime-delay fuse for AC polyphase motor branch-circuit short-circuit/ground-fault protection (Table 430.52)
Maximum 300% of motor full-load current; where the result is not a standard size, 430.52(C)(1) Exception No. 1 permits the next standard size from Table 240.6 — example: 300% × 65 A = 195 A → 200 A fuseHermetic refrigerant motor-compressor sizing from rated-load current (RLA)
Conductors ≥ 125% × RLA (30 A × 1.25 = 37.5 A; 20 A × 1.25 = 25 A); OCPD not more than 175% × RLA (30 A × 1.75 = 52.5 A; 20 A × 1.75 = 35 A); NEC 2023/2026 440.22(A) Exception No. 1 permits the next higher standard rating (60 A), while NEC 2017/2020 have no such exception so the device may not exceed 52.5 A (a 50 A device); if the device cannot carry starting current it may be increased to not more than 225% of RLA (67.5 A → 60 A)Pull and junction box dimensions for conductors 4 AWG or larger (314.28)
Straight pull: length ≥ 8 × trade size of largest raceway (8 × 3 in. = 24 in.). Angle/U pull or splice: distance from each raceway entry to opposite wall ≥ 6 × trade size of largest raceway, plus the sum of the diameters of the other raceway entries in the same row on the same wall (6 × 3 in. = 18 in.; 18 + 2 = 20 in.)Non-dwelling load calculations
Receptacles: not less than 180 VA per single or multiple receptacle on one yoke (220.14(I)) — 50 duplex = 50 × 180 VA. Non-dwelling receptacle demand (Table 220.47): first 10 kVA at 100% + remainder at 50% — 18 kVA → 10,000 + (8,000 × 0.50) = 14,000 VA. Retail lighting (Table 220.42(A)): 1.9 VA/ft² with the 125% continuous multiplier already included — 5,000 ft² × 1.9 = 9,500 VA