Exam Cheat Sheet · Quick Reference

ICC G17 Journeyman Electrician Exam (2017 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

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 ReadingNEC Code Structure, Scope, and Enforcement (Article 90)Equipment Approval, Listing, Labeling, and IdentificationWorking Space and Clearances Around Electrical Equipment (Article 110)Electrical Connections, Terminations, and Temperature RatingsArc-Flash Hazard Warnings, Equipment Markings, and Disconnecting Means IdentificationAC/DC Distribution System Configurations and Conductor Color CodingPower Factor, Impedance, Reactance, and Capacitance CalculationsApplied Math for Electricians (Fractions, Equations, Trigonometry, and Unit Conversions)

Services and Service Equipment 9 Q · 11%

Services and Fault CurrentService Load CalculationsService Equipment & Service ConductorsTransformersSystem Grounding and BondingTemporary Service WiringNumber of services permitted and service configurationsOverhead and underground service conductor requirements and clearancesService disconnecting means requirements and ratingsService overcurrent protection requirementsArc-flash hazard warning labels for service equipmentSurge arresters and surge-protective devices (SPDs) at services +1 more

Feeders 3 Q · 4%

Load CalculationsEquipment GroundingMinimum feeder conductor ampacity and sizing (Article 215)Overcurrent protection requirements for feedersFeeder conductor identification (grounded, ungrounded, and EGC)Ground-fault protection of equipment for feeders rated 1000A or moreOutside feeder installation requirements (clearances, wiring methods, disconnecting means)Neutral load calculations and demand factors for feedersDemand factors for dwelling and non-dwelling feeder loads (lighting, appliances, cooking equipment, dryers)

Branch Circuits and Conductors 15 Q · 19%

Branch Circuit CalculationOvercurrent ProtectionConductorsRequired Outlets & GFCI/AFCI ProtectionEquipment GroundingVoltage Drop Calculations (Single-Phase and Three-Phase)Conductor Insulation Types and Application EnvironmentsAmpacity Correction and Adjustment Factors (Temperature and Conduit Fill)Multiwire Branch Circuit RequirementsGrounded Conductor Identification and UseBranch-Circuit Voltage LimitationsFeeder and Service Load Demand Factors

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, MV)Conductor Fill Calculations and Conduit SizingPhysical Protection of Cables and RacewaysConduit Bending Techniques and CalculationsWireways, Auxiliary Gutters, and BuswaysCable Trays and Cablebus Systems +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 RequirementsNEMA Receptacle and Attachment Plug ConfigurationsLighting Track Installation and Construction RequirementsLow-Voltage Lighting System RequirementsRecessed Luminaire Installation and Clearance RequirementsDisconnecting Means for Fixed Electric Space-Heating EquipmentDisconnecting Means for Air-Conditioning and Refrigerating Equipment +1 more

Control Devices 3 Q · 4%

Switches, Disconnects and ControllersMotor controller ratings and marking requirements (NEC Article 430)Motor control circuit overcurrent protection and wiring (Article 430 Part VI)Motor disconnecting means types, location, and ratings (Article 430 Part IX)Stop-start station control circuits and jogging/inching circuitsHand-off-automatic (HOA) control schemesClass 1, Class 2, and Class 3 remote-control circuit classifications and power limitationsMotor control centers: overcurrent protection, grounding, and busbar requirementsIndustrial control panel overcurrent protection, short-circuit ratings, and disconnecting means

Motors and Generators 5 Q · 6%

MotorsGeneratorsMotor branch-circuit conductor sizing (125% FLC rule)Motor branch-circuit short-circuit and ground-fault protection (Table 430.52 ratings)Motor overload protection (overload device selection and trip settings)Motor disconnecting means (types, ratings, and location requirements)Motor controllers (ratings, types, and marking requirements)Motor control centers (overcurrent protection, grounding, and marking)Locked-rotor current and code lettersCapacitors in motor circuits (conductor sizing, disconnecting means, and overload device adjustment)

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 I, II, III; Divisions 1 and 2; Zones 0, 1, 2, 20, 21, 22)Wiring Methods and Equipment for Hazardous LocationsSpecific Hazardous Occupancies (Commercial Garages, Aircraft Hangars, Motor Fuel Dispensing, Bulk Storage, Spray Application)Health Care Facilities Wiring and Essential Electrical SystemsStandby and Backup Power Systems (Legally Required Standby, Optional Standby, Critical Operations Power Systems, Fire Pumps) +3 more

Key Distinctions

Grounding Electrode Conductor (GEC)vsEquipment Grounding Conductor (EGC)

GEC size is based on the largest service-entrance conductor per NEC Table 250.66, while EGC size is based on the rating of the overcurrent device protecting the circuit per NEC Table 250.122.

Ugly's Electrical References, Page 109

Continuous LoadvsNoncontinuous Load

Feeder conductors must be sized at 125% of the continuous load but only 100% of the noncontinuous load when combined for minimum ampacity.

National Electrical Code or National Electrical Code Handbook, Pages 90-91 (Section 215.2(A)(1)(a))

Nontime-Delay Fuse (motor protection)vsDual Element (Time-Delay) Fuse (motor protection)

A nontime-delay fuse is permitted up to 300% of motor full-load current for single-phase motors, while a dual element time-delay fuse is limited to 175% of full-load current.

Ugly's Electrical References, Page 38

Inverse Time Circuit Breaker (motor protection)vsInstantaneous Trip Breaker (motor protection)

An inverse time breaker for a wound rotor motor is limited to 150% of full-load current, whereas an instantaneous trip breaker for a DC constant voltage motor is limited to 250% of full-load current.

Ugly's Electrical References, Page 38

Feeder ConductorsvsTap Conductors

When a single main OCPD is located inside an industrial control panel rather than ahead of it, the supply conductors are treated as feeders or taps per NEC 240.21, not as service conductors.

NEC 2017 Handbook, Section 409.21(B)

120/240V Single-Phase Three-Wire Systemvs120/240V Three-Phase Four-Wire Delta High-Leg System

The single-phase system uses black and red for ungrounded conductors; the delta high-leg system requires the B phase (high leg) to be colored orange or tagged.

Common Electrical Distribution Systems

Grounded Neutral Conductor (6 AWG or smaller)vsGrounded Neutral Conductor (larger than 6 AWG)

Conductors 6 AWG or smaller must have a continuous white or gray outer finish per 200.6(A), while larger conductors have alternative identification methods.

National Electrical Code Handbook, Page 58 (Article 200.6(A))

NEC Table 4 (Conduit Fill)vsNEC Chapter 9, Table 5 (Conductor Area)

Table 4 provides the usable area within a selected conduit or tubing, while Table 5 provides the required cross-sectional area for each individual conductor.

NEC Handbook, Section 342.22

Series Circuit CurrentvsThree-Phase Circuit Current

In a series circuit the total current equals the current in every part (IT = I1 = I2 …), while three-phase current calculations require multiplying by the factor 1.73 (√3).

Series Circuits

Lampholder SymbolvsLampholder with Pull Switch Symbol

A standard lampholder has its own symbol on electrical plans, while a lampholder with a pull switch adds the designation 'PS' to distinguish it.

NEC Handbook, Section 410.1 (Electrical Symbols reference)

NEC 240.4(B) Next Higher Standard RatingvsNEC 240.4(D) Small Conductor Protection

Section 240.4(B) permits using the next higher standard OCPD above conductor ampacity up to a maximum of 800 amperes, while 240.4(D) sets absolute maximums for small conductors (e.g., 15A for 14 AWG copper).

National Electrical Code Handbook, Pages 149-150

277/480V Three-Phase Four-Wire Wye Systemvs120/208V Three-Phase Four-Wire Wye System

In the 277/480V wye system the C phase is yellow and phase-to-neutral is 277V, while in the 120/208V wye system phase-to-neutral is 120V and phase-to-phase is 208V.

Ugly's Electrical References, Common Electrical Distribution Systems

Key Terms

Authority Having Jurisdiction (AHJ) Article 90.4(B)

Per NEC Article 90.4, the AHJ is responsible for making interpretations of NEC rules, approving equipment and materials, and granting special permissions.

Ampacity Correction Factor Baseline Temperature NEC, Section 310.15(B)

Per NEC Section 310.15(B), ampacity correction factors must be applied whenever ambient temperature differs from the standard baseline of 30°C (86°F).

Ground-Fault Protection of Equipment (GFPE) Threshold National Electrical Code Handbook, Page 152

Per NEC Section 240.13, GFPE is required for solidly grounded wye systems over 150V to ground but not exceeding 1000V phase-to-phase when the main disconnecting means is rated 1000 amperes or more.

Motor Full-Load Current Table Reference National Electrical Code Handbook, Page 496, Section 430.6(A)(1)

Per NEC Section 430.6(A)(1), Tables 430.247–430.250 (not the motor nameplate) shall be used to determine conductor ampacity and OCPD ratings for general motor applications.

Part-Winding Start Motor Protection National Electrical Code Handbook, Page 495, Section 430.4

Per NEC Section 430.4, each motor-winding connection of a standard part-winding start induction motor shall have branch-circuit short-circuit and ground-fault protection rated at not more than one-half the value specified by Section 430.52.

Coordinated Overcurrent Protection System National Electrical Code Handbook, Page 152

Per NEC Section 240.12, where orderly shutdown is required to minimize hazards, the system shall be based on coordinated short-circuit protection and overload indication from monitoring systems or devices.

Common Neutral Feeder Limit National Electrical Code or National Electrical Code Handbook, Page 93

Per NEC Section 215.4(A), up to three sets of 3-wire feeders or two sets of 4-wire or 5-wire feeders are permitted to share a common neutral conductor.

Outdoor Overhead Conductor Minimum Size National Electrical Code or National Electrical Code Handbook, Page 114 (Section 225.6(A))

Per NEC Section 225.6(A)(1), outdoor overhead individual conductors at 1000V or less must be at least 10 AWG copper for spans up to 50 ft and 8 AWG copper for longer spans unless supported by a messenger wire.

Open Conductor Separation Requirement National Electrical Code or National Electrical Code Handbook, Page 116

Per NEC Section 225.14(C), open conductors shall be separated from open conductors of other circuits or systems by not less than 100 mm (4 inches).

Receptacle Load Calculation National Electrical Code or National Electrical Code Handbook, Page 99

Per NEC Section 220.14(I), each single or multiple receptacle on one yoke shall be calculated at not less than 180 volt-amperes.

Heavy-Duty Lampholder Load Calculation National Electrical Code or National Electrical Code Handbook, Page 98

Per NEC Section 220.14(E), outlets for heavy-duty lampholders shall be calculated at a minimum of 600 volt-amperes.

Service Raceway Contents Exception National Electrical Code Handbook, Page 129 (Article 230.7, Exception No. 1)

Per NEC Section 230.7 Exception No. 1, grounding electrode conductors and supply-side bonding jumpers are permitted within service raceways alongside service conductors.

Delta High-Leg (B Phase) Identification Ugly's Electrical References, Common Electrical Distribution Systems

In a 120/240V three-phase four-wire delta system, the B phase high leg must be colored orange or tagged because it measures approximately 208V to the neutral.

Type AC Cable Bending Radius National Electrical Code or National Electrical Code Handbook, Page 306

Per NEC Section 320.24, the inner edge bend radius of Type AC (armored) cable shall not be less than five times the cable's outer diameter.

NEC Scope Exclusions Article 90.2(D)

Per NEC Article 90.2(B), the Code does not cover ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles.

Dwelling Unit Lighting Load National Electrical Code or National Electrical Code Handbook, Page 97 (Table 220.12)

Per NEC Table 220.12, the minimum unit lighting load for dwelling units is 3 volt-amperes per square foot of floor area.

Formulas to Know

Ohm's Law – CurrentI (Amperes) = E (Volts) ÷ R (Ohms)

Ohm's Law – VoltageE (Volts) = I (Amperes) × R (Ohms)

Ohm's Law – ResistanceR (Ohms) = E (Volts) ÷ I (Amperes)

Power – Volts × AmpsP (Watts) = E (Volts) × I (Amperes)

Power – Voltage SquaredP (Watts) = E² ÷ R

Three-Phase KilowattsKW = (E × I × PF × 1.73) ÷ 1000

Three-Phase Motor Amperes (HP known)I = (HP × 746) ÷ (E × %EFF × PF × 1.73)

Feeder Conductor Ampacity (Continuous + Noncontinuous Loads)Min. Ampacity = Noncontinuous Load (A) + (Continuous Load (A) × 1.25)

Motor Feeder Conductor SizeFeeder Ampacity = (Largest Motor FLC × 1.25) + Sum of All Other Motor FLCs

Motor Branch-Circuit OCPD – Nontime-Delay Fuse (Single-Phase)Max Fuse Rating = FLC × 3.00 (300%); if result not a standard size, use next higher standard size per Table 240.6(A)

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