Exam Cheat Sheet · Quick Reference
Texas - Journeyman Electrician - NEC Knowledge Portion
Texas · 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
59
Passing score
70%
Exam time
130 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Texas State Portion 59 questions
Definitions, Theory, and Plans
3 Q · 5%
Purpose and scope of the NEC (practical safeguarding of persons and property)Installations covered and not covered by the NECMandatory vs. permissive vs. explanatory language (shall, shall be permitted, informational notes)NEC code arrangement and chapter hierarchy (Chapters 1–9, annexes)Authority having jurisdiction (AHJ): enforcement, interpretations, and special permissionEquipment examination, listing, and approval for safetyWiring planning principles (future expansion, circuit limitations in enclosures)Units of measurement (SI vs. inch-pound, hard vs. soft conversion)
Electrical Services, Service Equipment, and Separately Derived Systems
6 Q · 11%
Service conductor clearances and wiring methods (overhead and underground)Service disconnecting means — location, rating, and number of disconnectsService entrance conductor sizing, ampacity, and insulation requirementsGrounding electrode system — types, installation, and conductor sizing (Article 250 Part III)Separately derived systems — grounding, bonding, and system bonding jumper requirementsMain bonding jumper and supply-side bonding jumper sizing and installationService equipment overcurrent protection and ground-fault protection of equipmentService load calculations — feeder and service demand factors for dwelling and non-dwelling occupancies
Electrical Feeders
3 Q · 5%
Minimum feeder conductor ampacity for continuous and noncontinuous loads (125% rule)Feeder overcurrent protection ratings and requirementsFeeder load calculations including demand factors for dwelling units and other occupanciesGround-fault protection of equipment for feeders rated 1000 amperes or moreFeeder conductor identification (grounded, equipment grounding, and ungrounded conductors)Surge-protective device requirements for feeders supplying dwelling and sleeping unitsOutside feeder clearances, conductor support, and disconnecting means for separate buildingsFeeder neutral load calculations and permitted reductions
Branch Circuits and Conductors
10 Q · 18%
GFCI protection requirements for dwelling and non-dwelling locationsAFCI protection requirements and permitted means of protectionBranch circuit ratings and permissible loads by circuit sizeConductor minimum ampacity and sizing for branch circuitsOvercurrent protection for branch-circuit conductors and equipmentRequired receptacle outlet placement in dwelling unitsMultiwire branch circuit requirements and disconnecting meansBranch circuit load calculations including continuous and noncontinuous loads
Electrical Wiring Methods and Electrical Materials
10 Q · 18%
Uses permitted and not permitted for Type AC, MC, NM, and NMC cablesSecuring and supporting requirements for cables and raceways (spacing intervals, fastening distances)Conductor ampacity tables and temperature correction/adjustment factorsProtection against physical damage (bored holes, notches, framing members, steel plate requirements)Bending radius requirements for cables and conduitFlexible cord and flexible cable types, uses permitted, and uses not permittedRigid Metal Conduit (RMC) and Intermediate Metal Conduit (IMC) installation requirementsBoxes, fittings, and conductor continuity requirements for wiring methods
Electrical Equipment and Devices
10 Q · 18%
Switch ratings, types, and permitted uses (AC/DC snap switches, dimmers, CO/ALR, motor-circuit)Receptacle installation requirements, ratings, and GFCI/AFCI/tamper-resistant protectionMotor branch-circuit conductor sizing and overload protection requirementsSwitchboard, switchgear, and panelboard installation, overcurrent protection, and groundingLuminaire installation locations, support, grounding, and wiring requirementsDisconnecting means requirements for motors, appliances, and air-conditioning equipmentTransformer overcurrent protection, installation types, and vault construction requirementsGenerator ratings, overcurrent protection, disconnecting means, and GFCI requirements
Motors and Generators
5 Q · 9%
Motor branch-circuit conductor sizing (125% rule and special motor types)Branch-circuit short-circuit and ground-fault protective device ratings (Table 430.52)Motor overload protection requirements and trip current percentagesMotor disconnecting means type, location, and current rating requirementsMotor controller ratings, markings, and application requirementsGenerator conductor ampacity, overcurrent protection, and disconnecting meansMotor control circuit overcurrent protection and conductor requirementsMotor and generator grounding, bonding, and nameplate marking requirements
Electrical Control Devices and Disconnecting Means
1 Q · 2%
Switch connection requirements and grounded conductor rules (404.2)Rating and use of switches for specific load types (404.14)Motor disconnecting means location, type, and rating requirements (430.102, 430.109, 430.110)Service disconnecting means requirements, location, and rating (230.70, 230.71, 230.79)Accessibility, height, and grouping requirements for switches and circuit breakers (404.8)Circuit breakers used as switches — marking, indicating, and application (404.7, 404.11, 240.81–240.85)Industrial control panel and motor control center disconnecting means and overcurrent protection (409.20–409.22, 430.92–430.99)Switch and enclosure installation requirements for damp/wet locations and enclosure grounding (404.4, 404.12)
Special Occupancies, Equipment, and Conditions
6 Q · 11%
Classification of hazardous locations by Class, Division, and Group (Classes I, II, III; Divisions 1 and 2; Groups A–G)Protection techniques for hazardous locations (explosionproof, dust-ignitionproof, intrinsically safe, purged/pressurized, nonincendive, etc.)Wiring methods permitted in Class I, II, and III Division 1 and 2 locations (conduit types, cable types, sealing requirements)Equipment marking requirements for hazardous locations (class, division, group, temperature class/T-code)Sealing and bonding requirements for conduit and cable systems in hazardous locationsSpecial occupancy hazardous location requirements (commercial garages, motor fuel dispensing facilities, aircraft hangars, cannabis oil systems)Intrinsically safe systems installation requirements (Article 504 – wiring methods, separation, grounding, identification)Zone classification systems as alternatives to Division classification (Zone 0/1/2 for gases; Zone 20/21/22 for dusts)
Renewable Energy Technologies
2 Q · 4%
PV system DC circuit maximum voltage calculations and temperature correction factorsRapid shutdown requirements for PV systems on buildingsPV system disconnecting means requirements and markingsOvercurrent protection for PV system DC circuitsPV system wiring methods, conductor identification, and labelingGrounding and bonding requirements for PV systemsInterconnection of power production sources to other systems (Article 705)Energy storage system disconnecting means and circuit requirements
Key Distinctions
Class I, Division 1vsClass I, Division 2
Division 1 locations have flammable gases or vapors present under normal operating conditions, while Division 2 locations normally confine hazardous materials in closed containers that can escape only upon accidental rupture.
NEC 500.5(B)(2)Grounded Conductor Identification (6 AWG or smaller)vsEquipment Grounding Conductor Identification
Grounded conductors 6 AWG or smaller must have a continuous white or gray outer finish (or three white/gray stripes), while green is reserved exclusively for equipment grounding conductors.
NEC 200.6(A)Conductor Ampacity (Table 310.16)vsMaximum Overcurrent Protection (NEC 240.4(D))
A 12 AWG THWN copper conductor has a Table 310.16 ampacity of 25 amperes, but NEC 240.4(D) limits overcurrent protection for 12 AWG to 20 amperes.
NEC Table 310.16Continuous Load Conductor SizingvsNoncontinuous Load Conductor Sizing
Conductors supplying continuous loads must be sized at 125% of the continuous load plus 100% of any noncontinuous load, whereas noncontinuous loads alone require only 100% of the load for ampacity.
NEC 210.19(A)(1)Direct-Buried Cable — General LocationvsDirect-Buried Cable — GFCI-Protected Residential 120V ≤20A
General-location direct-buried cables require a minimum cover of 600 mm (24 in.), while residential branch circuits rated 120V or less with GFCI protection require only 300 mm (12 in.).
NEC Table 300.5(A)Multiwire Branch Circuit Neutral IdentificationvsMultiwire Branch Circuit Disconnecting Means
Neutral conductors must be identified or grouped with their corresponding ungrounded conductors at least once per enclosure, while the disconnecting means must simultaneously open all ungrounded conductors at the origin.
NEC 200.4(B), 210.4(D)Standard Branch-Circuit Ratings (Multioutlet)vsIndividual Branch-Circuit Ratings
Multioutlet (other-than-individual) branch circuits are limited to standard ratings of 10, 15, 20, 30, 40, and 50 amperes, while individual branch circuits are not restricted to these standard ratings.
NEC 210.18Flexible Cord EGC Sizing (NEC 400.23)vsRaceway/Cable EGC Sizing (NEC 250.122 Table)
Equipment grounding conductors in flexible cords may be as small as 18 AWG per NEC 400.23, whereas NEC 250.122 Table normally requires a minimum of 14 AWG for raceway/cable installations.
NEC 400.23Motor FLC from NEC Table 430.248vsMotor Nameplate Current
NEC 430.6(A)(1) requires branch-circuit sizing for single-phase AC motors to use Table 430.248 full-load current values, not the motor nameplate markings.
NEC 430.6(A)(1) and Table 430.248Vertical Raceway Support — Copper 18 AWG–1/0 AWGvsVertical Raceway Support — Aluminum/Copper-Clad Aluminum
Copper conductors 18 AWG through 1/0 AWG in vertical raceways must be supported at maximum 30 m (100 ft) intervals, while aluminum or copper-clad aluminum conductors in the same size range are permitted up to 60 m (200 ft) intervals.
NEC Table 300.19(A)Grounded Conductor ID — Same Voltage SystemvsGrounded Conductor ID — Multiple Voltage Systems in Same Raceway
A single white or gray finish satisfies identification for grounded conductors on one voltage system, but when conductors of different nominal voltage systems share a raceway each grounded conductor must additionally be identified by its nominal voltage system.
NEC 200.6(A)Flexible Cord Splice RulevsParallel Conductor Raceway Rule
Flexible cords must be installed in continuous lengths without splice or tap (NEC 400.13), whereas conductors run in parallel are permitted provided each raceway contains all circuit conductors of that set.
NEC 400.13Key Terms
Continuous Load — 125% Conductor Sizing (NEC 210.19(A)(1)) NEC 210.19(A)(1)
Branch-circuit conductors must have an ampacity not less than the noncontinuous load plus 125% of the continuous load.
Small-Appliance Branch Circuits Required — Dwelling Units (NEC 210.11(C)(1)) NEC 210.11(C)(1)
Dwelling units must have two or more 20-ampere small-appliance branch circuits for receptacle outlets specified in NEC 210.52(B).
Maximum Dwelling-Unit Voltage for Cord-and-Plug Loads (NEC 210.6(A)) NEC 210.6(A)
In dwelling units, voltage shall not exceed 120 volts nominal between conductors supplying cord-and-plug-connected loads of 1,440 VA or less, or less than 1/4 hp.
Household Range Minimum Branch-Circuit Rating (NEC 210.19(C)) NEC 210.19(C)
Household ranges rated 8-3/4 kW or more require a minimum branch-circuit rating of 40 amperes.
AFCI Protection — Dwelling Unit Bedrooms (NEC 210.12(B)) NEC 210.12(B)
All 120-volt, single-phase, 10-, 15-, and 20-ampere branch circuits supplying outlets in dwelling unit bedrooms must be protected by any of the means described in NEC 210.12(A)(1) through (A)(6).
Multiwire Branch Circuit Simultaneous Disconnect (NEC 210.4(B)) NEC 210.4(B)
Each multiwire branch circuit must be provided with a means that simultaneously disconnects all ungrounded conductors at the point where the circuit originates.
Neutral Grouping in Enclosures (NEC 200.4(B) / 210.4(D)) NEC 200.4(B), 210.4(D)
Where multiple neutrals of different circuits share an enclosure, each grounded conductor must be identified or grouped with its corresponding ungrounded conductors at least once within that enclosure.
Free Conductor Length at Outlets (NEC 300.14) NEC 300.14
At least 150 mm (6 in.) of free conductor, measured from where it emerges from its raceway or cable sheath, must be left at each outlet, junction, and switch point.
Cable Protection in Bored Holes (NEC 300.4(A)(1)) NEC 300.4(A)(1)
Holes bored through wood members must be at least 32 mm (1-1/4 in.) from the edge of the wood member; otherwise, a steel plate or bushing is required.
All-Conductors-Same-Raceway Rule (NEC 300.3(B)(1)) NEC 300.3(B)(1)
All conductors of the same circuit must be in the same raceway, cable, or trench, except in approved parallel installations where each raceway contains all circuit conductors.
Single-Phase AC Motor FLC Table (NEC 430.6(A)(1)) NEC 430.6(A)(1) and Table 430.248
Full-load current values for single-phase AC motors must be taken from NEC Table 430.248, not from the motor nameplate.
Flexible Cord EGC Minimum Size (NEC 400.23) NEC 400.23
Equipment grounding conductors in flexible cords may be as small as 18 AWG copper, matching the cord's circuit conductors, rather than the 14 AWG minimum that NEC Table 250.122 would otherwise require.
Class I, Division 2 Location (NEC 500.5(B)(2)) NEC 500.5(B)(2)
A location where volatile flammable gases or vapors are normally confined within closed containers and can escape only upon accidental rupture or breakdown.
12 AWG THWN Ampacity (NEC Table 310.16) NEC Table 310.16
A 12 AWG copper THWN conductor has a table ampacity of 25 amperes at 30°C ambient; the 20-ampere value is the overcurrent protection limit under NEC 240.4(D), not the ampacity.
Grounded Conductor Identification — 6 AWG or Smaller (NEC 200.6(A)) NEC 200.6(A)
Grounded conductors 6 AWG or smaller must be identified by a continuous white or gray outer finish, or three continuous white or gray stripes; green is not permitted.
Standard Branch-Circuit Ratings (NEC 210.18) NEC 210.18
Branch circuits other than individual branch circuits shall be rated at 10, 15, 20, 30, 40, or 50 amperes — 25 amperes is not a recognized standard rating.
Formulas to Know
Minimum Conductor Ampacity — Continuous + Noncontinuous Load
Ampacity ≥ (Noncontinuous Load) + 1.25 × (Continuous Load)Branch-Circuit Overcurrent Device Size — Continuous Load
OCPD Rating ≥ 1.25 × (Continuous Load) + 1.0 × (Noncontinuous Load)Single-Phase Power
P (W) = V (volts) × I (amps) × PFThree-Phase Power
P (W) = √3 × V_L (volts) × I_L (amps) × PFVoltage Drop (single-phase)
VD = (2 × K × I × L) / CM [K = 12.9 for copper, L = one-way length in feet, CM = circular mils]Percent Voltage Drop
% VD = (VD / V_source) × 100Ohm's Law
V = I × R (also: I = V/R, R = V/I)Motor Full-Load Current (single-phase) — sizing multiplier
Branch-circuit conductor ampacity ≥ 1.25 × FLC (from Table 430.248)