Exam Cheat Sheet · Quick Reference
Texas Journeyman Lineman Electrician
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
40
Passing score
70%
Exam time
120 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Texas State Portion 40 questions
Definitions and Theory
6 Q · 15%
Purpose and scope of the NEC: practical safeguarding of persons and propertyInstallations covered vs. not covered by the NECMandatory vs. permissive vs. explanatory rules (shall/shall not vs. shall be permitted)Authority having jurisdiction (AHJ): enforcement, interpretations, and special permissionNEC code arrangement: chapters 1–9 and informative annexesListed equipment and examination of equipment for safetyUnits of measurement: SI vs. inch-pound, hard vs. soft conversionWiring planning: future expansion and limiting circuits in enclosures
Electrical Services and Service Equipment
8 Q · 20%
Service disconnecting means: location, rating, and maximum number requirementsOverhead and underground service conductor clearances, sizing, and wiring methodsService equipment grounding, bonding, and main bonding jumper requirementsOvercurrent protection for service conductors: location, rating, and ground-fault protectionNumber of services permitted and conditions for additional servicesService entrance conductor installation: insulation, supports, raceway sealing, and physical protectionSurge-protective device requirements for service equipment in dwelling and similar occupanciesEmergency disconnects for one- and two-family dwellings and supply-side equipment connections
Electrical Feeders
4 Q · 10%
Minimum feeder conductor ampacity for continuous and noncontinuous loads (125% rule and exceptions)Feeder overcurrent protection requirements and ratingsFeeder load calculations including demand factors for dwelling units, multifamily, and non-dwelling occupanciesGround-fault protection of equipment requirements for feeders rated 1000A or more on solidly grounded wye systemsFeeder conductor identification (grounded, equipment grounding, and ungrounded conductors)Surge-protective device (SPD) requirements for feeders supplying dwelling units and similar occupanciesOutside feeder requirements including overhead clearances, conductor support, and disconnecting means for separate buildingsFeeder taps rules including 10-foot, 25-foot, and outside tap provisions
Branch Circuit Calculations and Conductors
2 Q · 5%
Minimum conductor ampacity and sizing for continuous and noncontinuous loads (210.19, 220.10)Branch circuit ratings, overcurrent protection, and standard ampere ratings (210.18, 210.20, 240.6)GFCI protection requirements by location for dwelling and non-dwelling units (210.8)AFCI protection requirements and permitted means of protection (210.12)Conductor ampacity tables, temperature correction, and adjustment factors for more than three current-carrying conductors (310.15, 310.16)Dwelling unit load calculations including general lighting, small appliance, and laundry circuits (220.41, 220.52)Demand factors for ranges, dryers, and other household cooking appliances (220.55, 220.54)Multiwire branch circuit requirements including disconnecting means and line-to-neutral loads (210.4)
Electrical Wiring Methods and Electrical Materials
2 Q · 5%
Conductor ampacity tables and temperature ratings (Tables 310.16, 310.17, 310.18, 310.19)Ampacity correction and adjustment factors for ambient temperature and number of current-carrying conductorsUnderground installation requirements and minimum cover depths (Table 300.5(A))Physical protection of cables and raceways through wood members, metal framing, and shallow groovesConductor types, insulation designations, and permitted uses by location (dry, damp, wet)Box and conduit body fill calculations and sizing requirementsSecuring and supporting requirements for wiring methods (AC cable, MC cable, NM cable, RMC, IMC, FMC)Uses permitted and not permitted for specific wiring methods (Type AC, MC, NM, RMC, IMC, FMC)
Electrical Equipment and Devices
10 Q · 25%
Switch types, ratings, and load control requirements (Articles 404.14, 404.11, 404.13)Receptacle installation, grounding, and replacement requirements (Article 406.4)Switchboard, switchgear, and panelboard installation and overcurrent protection (Article 408)Motor branch-circuit conductor sizing, overload protection, and disconnecting means (Article 430)Luminaire installation locations, supports, and wiring requirements (Article 410)Transformer overcurrent protection, installation types, and vault requirements (Article 450)Air-conditioning and refrigerating equipment branch-circuit protection and disconnecting means (Article 440)Appliance branch circuits, disconnecting means, and GFCI protection (Article 422)
Motors and Generators
2 Q · 5%
Motor branch-circuit conductor sizing and ampacity requirements (Article 430, Part II)Motor overload protection devices, ratings, and placement (Article 430, Part III)Branch-circuit short-circuit and ground-fault protection ratings and device selection (Article 430, Part IV)Motor controller ratings, types, and marking requirements (Article 430, Parts VII-VIII)Disconnecting means location, type, and current rating for motors and controllers (Article 430, Part IX)Generator installation requirements including overcurrent protection, conductor ampacity, and disconnecting means (Article 445)Motor and controller grounding and bonding requirements (Article 430, Part XIII)Adjustable-speed drive systems conductor sizing and overload/overtemperature protection (Article 430, Part X)
Electrical Control Devices and Disconnecting Means
6 Q · 15%
Service disconnecting means requirements: location, rating, and number of disconnectsSwitch types, ratings, and permitted uses (AC/DC snap switches, knife switches, dimmers, circuit breakers as switches)Motor disconnecting means: location, type, current rating, and interrupting capacitySwitch and circuit breaker installation: enclosures, accessibility, height, and indicating requirementsMotor controller types, ratings, and disconnecting requirementsPanelboard, switchboard, and switchgear overcurrent protection and disconnecting meansIndustrial control panel disconnecting means and overcurrent protectionSwitch and enclosure installation in damp or wet locations
Key Distinctions
NEC Chapters 1 through 4vsNEC Chapters 5, 6, and 7
Chapters 1–4 apply generally to all electrical installations, while Chapters 5, 6, and 7 apply to special occupancies, special equipment, or other special conditions and may supplement or modify Chapters 1 through 7.
NEC 2026 Section 90.3NEC Chapters 1 through 7vsNEC Chapter 8
Chapter 8 covers communications systems and is not subject to the requirements of Chapters 1 through 7 except where those requirements are specifically referenced in Chapter 8.
NEC 2026 Section 90.3SI (metric) unitsvsInch-pound units
In the NEC's dual system of units, SI (modernized metric/International System of Units) units appear first and are the preferred system, with inch-pound units following in parentheses.
NEC 2026 Section 90.9Continuous loadvsNoncontinuous load
For minimum branch-circuit or feeder conductor ampacity, continuous load is taken at 125% while noncontinuous load is taken at 100%.
NEC 2026 Section 210.1910-ampere branch circuitvs15- and 20-ampere branch circuits
10 amperes is a recognized standard branch-circuit rating (10, 15, 20, 30, 40, 50 A), but 10-ampere branch circuits are specifically prohibited from supplying receptacle outlets.
NEC 2026 Section 210.18 Exception No. 2, NEC 210.23Small-appliance branch circuits (dwelling)vsLaundry branch circuit (dwelling)
Dwelling units require two or more 20-ampere small-appliance branch circuits for the receptacle outlets of 210.52(B), plus at least one additional 20-ampere branch circuit for the laundry receptacle outlet(s) of 210.52(F) with no other outlets.
NEC 2026 Section 210.11GFCI protection (Class A)vsAFCI protection
A listed Class A GFCI protects personnel (e.g., receptacles within 1.8 m/6 ft of the top inside edge of a sink bowl in dwellings), while AFCI protection is required for 120-volt, single-phase, 10-, 15- and 20-ampere branch circuits supplying listed dwelling areas such as bedrooms, kitchens and living rooms (garages, unfinished basements and bathrooms are not listed).
NEC 2026 Section 210.8Multiwire branch circuit simultaneous disconnectvsMultiwire branch circuit load limitation
Each multiwire branch circuit must have a means to simultaneously disconnect all ungrounded conductors only at its origin, and it may supply only line-to-neutral loads unless an exception permits line-to-line loads.
NEC 2026 Section 210.4Grounded conductor terminal identificationvsOther (ungrounded) terminal identification
Terminals for the grounded conductor must be white or silver (on receptacles, polarized plugs and cord connectors, by a metal or metal coating that is white or silver), while other terminals must be a distinguishable different color.
NEC 2026 Section 200.10Flexible cord minimum size (general applications)vsPortable cable over 600 V up to 2000 V minimum size
Most common flexible cord types (S, SJ, SO, SJO, etc.) have a minimum conductor size of 18 AWG, while multiconductor portable cable over 600 volts up to 2000 volts nominal must be 12 AWG copper or larger with flexible stranding.
NEC 2026 Section 400.21, Table 400.4Motor overload protectionvsInverse time circuit breaker (short-circuit/ground-fault) sizing
Overload protection is set at 115% of FLC (up to 125% for motors with service factor ≥1.15 or temperature rise ≤40°C), while an inverse time breaker for a single-phase motor may be set at 250% of FLC and, where needed for starting, increased to no more than 400% of FLC for currents of 100 A or less.
NEC Section 430.52(C)(1), Exception No. 2; Table 430.52(C)(1)Direct-buried conductor covervsConcrete-encased raceway envelope
Direct-buried cables or conductors in locations not otherwise specified require 600 mm (24 in.) of cover, whereas raceways approved for burial only where concrete encased require a concrete envelope at least 50 mm (2 in.) thick.
NEC 2026 Table 300.7(A)EMT run with no intermediate pull pointvsEMT run with a conduit body added mid-run
Bends are limited to 360° between pull points; because a conduit body is a pull point, each section on either side of it may have up to 360° of bends.
NEC 2026 Section 358.24(B) (EMT — number of bends in one run)Key Terms
Authority having jurisdiction (AHJ) NEC 2026 Section 90.4
The authority responsible for enforcing the Code, for making interpretations of the rules, for deciding on approval of equipment and materials, and for granting special permission contemplated in the rules.
Mandatory rules NEC 2026 Section 90.5
NEC rules identifying actions that are specifically required or prohibited, characterized by the terms 'shall' or 'shall not'.
Purpose/scope of the NEC NEC 2026 Section 90.2
The practical safeguarding of persons and property from hazards arising from the use of electricity; it is not a design specification or instruction manual for untrained persons, and it does not cover ships, watercraft other than floating buildings, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles.
NEC arrangement NEC 2026 Section 90.3
The Code is divided into the introduction and nine chapters.
Metric units in the NEC NEC 2026 Section 90.9
Metric units of measurement in accordance with the modernized metric system known as the International System of Units (SI), which appear first in the Code text.
Grounded conductor continuity NEC 2026 Section 200.4(B)
The continuity of a grounded conductor shall not depend on a connection to a metal enclosure, raceway, or cable armor.
Common, continuous grounded system NEC 2026 Section 200.5
Grounded conductors of premises wiring must be electrically connected to the supply system grounded conductor — a direct electrical connection capable of carrying current — to ensure a common, continuous grounded system.
Grounded conductor insulation rating (over 1000 V) NEC 2026 Section 200.4(A)
Grounded conductors must be rated not less than 600 volts for solidly grounded neutral systems over 1000 volts, in accordance with 250.184(A).
Screw-shell device grounded terminal NEC 2026 Section 200.10
For devices with screw shells, the terminal for the grounded conductor is the one connected to the screw shell.
Dwelling-unit branch-circuit voltage limit NEC 2026 Section 210.6
In dwelling units, voltage shall not exceed 120 volts nominal between conductors supplying terminals of luminaires and cord-and-plug-connected loads rated 1,440 volt-amperes nominal or less, or less than 1/4 horsepower.
Ground-fault protection of equipment (branch circuits) NEC 2026 Section 210.13
Required for each branch-circuit disconnecting means rated 1000 amperes or more installed on solidly grounded wye systems of more than 150 volts to ground but not exceeding 1000 volts phase-to-phase.
Multiple branch circuits on the same yoke NEC 2026 Section 210.7
Where two or more branch circuits supply devices or equipment on the same yoke or mounting strap, a means to simultaneously disconnect the ungrounded supply conductors must be provided at the point where the branch circuits originate (210.7).
Household range minimum branch-circuit rating NEC 2026 Section 210.19
For ranges rated 8¾ kW (8.75 kW) or more, the minimum branch-circuit rating is 40 amperes, and conductors supplying household cooking appliances must have ampacity not less than the branch-circuit rating.
Flexible cord surface marking NEC 2026 Section 400.6
Types S, SC, SE, SJ, SO, ST and other specified flexible cords must be durably marked on the surface at intervals not exceeding 610 mm (24 in.) with type designation, size, and number of conductors.
Flexible cord use restriction / overcurrent protection NEC 2026 Section 400.12
Flexible cords shall not be used as a substitute for the fixed wiring of a structure unless specifically permitted, and cords not smaller than 18 AWG are considered protected against overcurrent by the branch-circuit overcurrent device when approved for the connected load.
Type TF fixture wire NEC 2026 Table 402.13
Thermoplastic covered fixture wire (solid or 7-strand) with a maximum operating temperature of 60°C (140°F), used for fixture wiring.
Free conductor length at boxes NEC 2026 Section 300.16
At least 150 mm (6 in.) of free conductor must be left at each outlet, junction, and switch point for splices or connection of luminaires or devices.
Cable spacing from framing members NEC 2026 Section 300.6(D)
Cables run parallel to joists, rafters, or studs must be kept at least 32 mm (1¼ in.) from the nearest edge where nails or screws are likely to penetrate, or be protected by steel plates.
Vertical raceway conductor support NEC 2026 Table 300.21(A)
Copper conductors 6 AWG through 1/0 AWG (which includes 4 AWG) have a maximum unsupported vertical length of 30 m (100 ft).
Direct-buried splices without boxes NEC 2026 Section 300.7(E)
Direct-buried conductors or cables are permitted to be spliced or tapped without splice boxes provided the splices or taps are made in accordance with 110.14(B).
Sign ballast/transformer working space NEC 2026 Section 600.21
Where ballasts, transformers, and electronic power supplies for signs are not installed in a sign, a working space of at least 900 mm (3 ft) high × 900 mm (3 ft) wide × 900 mm (3 ft) deep must be provided at each unit.
Pull point (for bend limits) NEC 2026 Section 358.24(B) (EMT — number of bends in one run)
A point such as a conduit body that terminates a raceway section for purposes of the 360° maximum bends allowed between pull points.
Formulas to Know
Minimum branch-circuit or feeder conductor ampacity with continuous and noncontinuous loads
Ampacity ≥ (1.25 × continuous load) + (1.00 × noncontinuous load); e.g., 40 A cont. + 20 A noncont. = 50 + 20 = 70 A; 100 A cont. + 30 A noncont. = 125 + 30 = 155 AGenerator output conductor ampacity
Conductor ampacity ≥ 115% × generator nameplate current; 80 A × 1.15 = 92 A; 200 A × 1.15 = 230 A (conductors from generator terminals to first overcurrent device)Minimum feeder ampacity for multiple motors
(125% × FLC of largest motor) + sum of remaining motor FLCs; e.g., (1.25 × 15.2) + 15.2 + 15.2 = 19 + 30.4 = 49.4 AMotor overload protection maximum (430.32(A)(1))
Separate overload device ≤ 125% × nameplate FLC for motors with a marked service factor ≥ 1.15 or marked temperature rise ≤ 40°C; ≤ 115% × nameplate FLC for all other motors. These are maximums, not a range: 30 A → 37.5 A max (service factor 1.15) or 34.5 A max (other motors)Maximum inverse time circuit breaker rating for a motor
Standard: 250% × FLC for a single-phase motor (50 A × 2.5 = 125 A, next standard size 150 A if motor won't start); absolute maximum where needed for starting: 400% × FLC for currents 100 A or less (60 A × 4 = 240 A)Three-phase power and apparent power
P = √3 × V(line) × I × cos θ; S (kVA) = P (kW) ÷ PF, e.g., 200 kW ÷ 0.8 = 250 kVADwelling general lighting and circuit load calculation (Article 220; Article 120 in NEC 2026)
Total VA = (area in sq ft × 3 VA/sq ft) + (1,500 VA × number of small-appliance circuits) + (1,500 VA × number of laundry circuits); multiply per-unit total by number of units for multifamily before demand factors (e.g., 2,000 sq ft: 6,000 + 3,000 + 1,500 = 10,500 VA; 8,100 VA × 4 units = 32,400 VA)Series-parallel resistance and Ohm's law
Parallel pair: R = (R1×R2)/(R1+R2) or 1/Rp = 1/R2 + 1/R3; equal parallel branches: R = R/branches; series: R_total = R1 + Rp; I = E ÷ R_total; branch current = voltage across branch ÷ branch resistance (e.g., 24 V ÷ (2 + 18/3 = 8 Ω) = 3 A; 36 V ÷ 12 Ω = 3 A; 18 V ÷ 15 Ω = 1.2 A)Raceway (conduit) fill
Maximum 40% cross-sectional area fill for more than two conductors/cables; % fill = total conductor area ÷ conduit internal area, using area = π r² (e.g., 3 × π(0.125)² ≈ 0.147 in² ÷ π(0.5)² ≈ 0.785 in² ≈ 18.8%) [source questions [2420, 23036]; cite: NEC Chapter 9, Table 1]Parallel conductor sets — ampacity and grounded conductor sizing
Total ampacity = per-set ampacity × number of sets (350 kcmil Cu at 90°C, Table 310.16 = 350 A; 2 sets = 700 A); where service conductors are paralleled in 2 or more raceways, the grounded conductor is also paralleled and sized per raceway from that raceway's ungrounded conductors (NEC 250.24(C)(2)) — 350 kcmil Cu → 2 AWG by Table 250.102(C)(1), but not smaller than 1/0 AWG, so 1/0 AWG Cu in each raceway