Exam Cheat Sheet · Quick Reference
Texas - Journeyman Industrial 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
60
Passing score
70%
Exam time
180 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Texas State Portion 60 questions
Definitions, Theory, and Plans
7 Q · 12%
Purpose and scope of the NEC (practical safeguarding of persons and property)Installations 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, annexes, and their hierarchy)Equipment examination, listing, and approval for safetyWiring planning principles (future expansion, raceway space, circuit enclosure limits)Units of measurement (SI vs. inch-pound, hard vs. soft conversion)
Electrical Services, Service Equipment, and Separately Derived Systems
4 Q · 7%
Service conductor clearances and installation requirements (overhead and underground)Service disconnecting means location, rating, and maximum number of disconnectsService entrance conductor sizing, ampacity, and permitted wiring methodsService equipment overcurrent protection and ground-fault protection requirementsGrounding and bonding of service equipment, including main bonding jumper and grounding electrode systemSeparately derived system grounding, system bonding jumper, and grounding electrode conductor requirementsTransformer installation requirements, overcurrent protection, and vault constructionGenerator installation, overcurrent protection, disconnecting means, and emergency shutdown requirements
Electrical Feeders
4 Q · 7%
Minimum feeder conductor ampacity for continuous and noncontinuous loads (125% rule)Feeder overcurrent protection requirements and ratingsFeeder load calculations including demand factorsGround-fault protection of equipment for feeder disconnects rated 1000A or moreFeeder equipment grounding conductor requirements and sizingFeeder conductor identification (grounded, ungrounded, and EGC)Feeder taps rules (10-ft, 25-ft, and outside tap provisions)Surge-protective device requirements for feeders and common neutral feeder rules
Branch Circuit Calculations and Conductors
6 Q · 10%
Minimum conductor ampacity for continuous and noncontinuous loads (125% rule)Branch circuit ratings and permissible loads by circuit size (10A through 50A+)Overcurrent protection sizing and small conductor limits (240.4)Ampacity tables and correction/adjustment factors for temperature and conductor fill (Table 310.16, 310.15)GFCI protection requirements by location for dwelling and non-dwelling occupanciesAFCI protection requirements and approved means of protectionConductor identification for grounded, ungrounded, and equipment grounding conductorsMultiwire branch circuit requirements including simultaneous disconnection and line-to-neutral loads
Electrical Wiring Methods and Electrical Materials
10 Q · 17%
Conductor ampacity tables and temperature ratings (Tables 310.16–310.21)Ampacity correction and adjustment factors for ambient temperature and conductor bundlingUnderground installation requirements and minimum cover depths (Table 300.5)Physical protection of cables and raceways through framing members and structural elementsBox and conduit body fill calculations and sizing requirementsSecuring and supporting requirements for raceways, cables, and boxesUses permitted and not permitted for wiring methods (NM, AC, MC, EMT)Protection against corrosion and deterioration for raceways and enclosures
Electrical Equipment and Devices
6 Q · 10%
Switch types, ratings, and installation requirements (Articles 404, 408, 409)Motor circuit conductors, overload protection, and branch-circuit short-circuit protection (Article 430 Parts II, III, IV)Receptacle ratings, grounding, and installation requirements (Article 406)Panelboard and switchboard construction, overcurrent protection, and grounding (Article 408)Motor controllers, disconnecting means, and motor control centers (Article 430 Parts VII, VIII, IX)Luminaire installation, grounding, and location restrictions (Article 410)Air-conditioning and refrigerating equipment disconnecting means, branch-circuit protection, and overload protection (Article 440)Generator overcurrent protection, conductor ampacity, disconnecting means, and emergency shutdown (Article 445)
Motors and Generators
7 Q · 12%
Motor branch-circuit conductor sizing and ampacity requirements (430.22, 430.24)Motor overload protection selection and rating (430.32, 430.37)Branch-circuit short-circuit and ground-fault protection ratings for motors (430.52, Table 430.52(C)(1))Motor controller ratings, types, and disconnecting means requirements (430.83, 430.102, 430.109, 430.110)Motor nameplate markings and locked-rotor code letters (430.7, Table 430.7(B))Motor control centers: overcurrent protection, grounding, busbars, and marking (430.94 through 430.99)Generator installation requirements: marking, overcurrent protection, conductor ampacity, and disconnecting means (445.11 through 445.19)Adjustable-speed drive systems: conductor sizing, overload and overtemperature protection (430.122, 430.124, 430.126)
Electrical Control Devices and Disconnecting Means
3 Q · 5%
Motor disconnecting means location, type, and rating requirements (Article 430 Part IX)Switch ratings, types, and load control limitations (Article 404)Motor controller ratings, design requirements, and use as disconnecting means (Article 430 Parts VII, IX)Overcurrent protection for motor branch circuits and feeders (Article 430 Parts IV, V)Industrial control panel disconnecting means, overcurrent protection, and short-circuit ratings (Article 409)Service disconnecting means location, rating, and number of disconnects (Article 230 Part VI)Switchboard, switchgear, and panelboard overcurrent protection and disconnecting provisions (Article 408)Knife switch ratings, isolating switch restrictions, and position requirements (Article 404)
Special Occupancies, Equipment, and Conditions
6 Q · 10%
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, dusttight, hermetically sealed, etc.)Wiring methods for Class I, II, and III Division 1 and 2 locations (permitted conduit types, cable types, flexible connections, boxes and fittings)Sealing and drainage requirements for conduit and cable systems in hazardous locations (seal placement, compound requirements, fill limits)Equipment marking, temperature classification (T-codes), and approval requirements for hazardous locationsGrounding and bonding requirements specific to hazardous classified locations (Classes I, II, III)Health care facility electrical systems (patient care space wiring, essential electrical systems, isolated power systems, GFCI requirements)Swimming pools, fountains, and similar installations (GFCI/SPGFCI protection, grounding and bonding, listing requirements)
Electrical Safety
7 Q · 12%
Classification of hazardous locations (Class I, II, III; Division 1 and 2)Wiring methods and approved cable types for Class I, II, and III hazardous locationsSealing and drainage requirements for conduit and cable systems in hazardous locationsGrounding and bonding requirements in hazardous (classified) locationsEquipment protection techniques (explosionproof, dust-ignitionproof, intrinsic safety, purged/pressurized, nonincendive)Overcurrent protection requirements including conductor protection, fuse and circuit breaker ratings, and arc energy reductionGrounding electrode systems, grounding electrode conductors, and equipment grounding conductorsSurge protection and overvoltage protective devices in classified and general locations
Key Distinctions
Mandatory NEC RulevsPermissive NEC Rule
Mandatory rules use 'shall' or 'shall not' (required/prohibited), while permissive rules use 'shall be permitted' or 'shall not be required' (optional/alternative).
NEC 90.5(A)NEC Chapters 1–4vsNEC Chapters 5–7
Chapters 1–4 apply generally to all electrical installations, while Chapters 5–7 apply only to special occupancies, special equipment, or other special conditions and may supplement or modify Chapters 1–4.
NEC 90.3NEC Chapter 8vsNEC Chapters 1–7
Chapter 8 (communications systems) is NOT subject to the requirements of Chapters 1–7 unless specifically referenced within Chapter 8.
NEC 90.3Grounded ConductorvsEquipment Grounding Conductor (EGC)
Grounded conductors are identified by white, gray, or three white/gray stripes; EGCs are identified by a continuous green finish—green is never permitted for grounded conductors.
NEC 200.6(A)Class II Hazardous LocationvsClass III Hazardous Location
Class II locations are hazardous due to combustible dusts, while Class III locations are hazardous due to easily ignitible fibers or flyings that are not normally suspended in air in ignitable concentrations.
NEC 500.5(D)(1)1 Conductor in Conduit (53% fill)vs2 Conductors in Conduit (31% fill)
A single conductor may fill up to 53% of conduit cross-sectional area, whereas exactly two conductors are limited to 31% fill per NEC Table 1.
Table 12 Conductors in Conduit (31% fill)vsMore Than 2 Conductors in Conduit (40% fill)
Exactly two conductors are limited to 31% conduit fill, while any installation of more than two conductors is limited to 40% fill per NEC Table 1.
Table 1, Chapter 9Informational NotesvsMandatory/Permissive Rules
Informational Notes are included for explanatory purposes only and are not enforceable, whereas mandatory and permissive rules carry the force of the Code.
Article 90.5(C)NEC Coverage: Ships/WatercraftvsNEC Coverage: Mobile Homes/Recreational Vehicles
Ships and watercraft (other than floating buildings) are explicitly excluded from NEC coverage, while mobile homes and recreational vehicles are explicitly included.
NEC 90.2(D)Multiwire Branch CircuitvsStandard Branch Circuit
A multiwire branch circuit must provide a means to simultaneously disconnect ALL ungrounded conductors at the point of origin; a standard single branch circuit has no such simultaneous-disconnect requirement.
NEC 210.4(B)SI (Metric) UnitsvsInch-Pound Units
The NEC gives preference to SI (metric) units, which appear first; inch-pound units immediately follow in parentheses.
NEC 90.9(A), 90.9(B)Autotransformer-Derived Branch CircuitvsConventional Branch Circuit
A branch circuit derived from an autotransformer is only permitted if its grounded conductor is electrically connected to the grounded conductor of the supply system; conventional branch circuits have no such restriction.
NEC 210.9Key Terms
Purpose of the NEC (NEC 90.1(A) / 90.2(A)) NEC 90.2(A)
Per NEC 90.2(A), the Code's purpose is the practical safeguarding of persons and property from hazards arising from the use of electricity—not to serve as a design specification or instruction manual.
Authority Having Jurisdiction (AHJ) (NEC 90.4) NEC 90.4(B)
Per NEC 90.4(B), the AHJ is responsible for making interpretations of NEC rules, approving equipment and materials, and granting special permissions contemplated by the Code.
NEC Code Arrangement (NEC 90.3) Article 90.3
Per NEC 90.3, the Code consists of nine chapters: Chapters 1–4 apply generally, Chapters 5–7 cover special conditions, Chapter 8 covers communications systems (independent of Chapters 1–7), and Chapter 9 consists of applicable tables.
Mandatory Rule (NEC 90.5(A)) NEC 90.5(A)
Per NEC 90.5(A), a mandatory rule is one that requires or prohibits a specific action and is identified by the terms 'shall' or 'shall not.'
Permissive Rule (NEC 90.5(B)) NEC 90.5(B)
Per NEC 90.5(B), a permissive rule identifies an allowed but not required action and is characterized by the terms 'shall be permitted' or 'shall not be required.'
Informational Note (NEC 90.5(C)) Article 90.5(C)
Per NEC 90.5(C), Informational Notes are explanatory material included in the Code for informational purposes only and are not enforceable as Code requirements.
Conduit Fill – More Than 2 Conductors (NEC Table 1, Chapter 9) Table 1, Chapter 9
Per NEC Table 1, when more than 2 conductors are installed in a conduit or tubing, the maximum allowable fill is 40% of the conduit's cross-sectional area.
Class III, Division 1 Location (NEC 500.5(D)(1)) NEC 500.5(D)(1)
Per NEC 500.5(D)(1), a Class III, Division 1 location is one where easily ignitible fibers or materials producing combustible flyings are handled, manufactured, or used.
Grounded Conductor Identification – 6 AWG or Smaller (NEC 200.6(A)) NEC 200.6(A)
Per NEC 200.6(A), grounded conductors 6 AWG or smaller must have a continuous white finish, continuous gray finish, or three continuous white/gray stripes; green is not permitted.
Multiwire Branch Circuit Disconnection (NEC 210.4(B)) NEC 210.4(B)
Per 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 branch circuit originates.
EGC in Flexible Cord – 15A Circuit (NEC 250.122(E)) NEC 250.122(E)
Per NEC 250.122(E), the equipment grounding conductor in a flexible cord shall not be smaller than 18 AWG and shall not be smaller than the circuit conductors—making 14 AWG the minimum for a 15-ampere circuit.
Grounded Conductor Continuity (NEC 200.2(B)) NEC 200.2(B)
Per NEC 200.2(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 200.3) NEC 200.3
Per NEC 200.3, grounded conductors of premises wiring systems must be electrically connected to the supply system grounded conductor to ensure a common, continuous grounded system.
Grounded Conductor Terminal Color (NEC 200.10(B)) NEC 200.10(B)
Per NEC 200.10(B), the terminal on receptacles, attachment plugs, and cord connectors intended for the grounded conductor must be white or silver in color.
Autotransformer Branch Circuit Restriction (NEC 210.9) NEC 210.9
Per NEC 210.9, branch circuits shall not be derived from autotransformers unless the supplied circuit's grounded conductor is electrically connected to the grounded conductor of the system supplying the autotransformer.
Household Range Branch Circuit Minimum (NEC 210.19(C)) NEC 210.19(C)
Per NEC 210.19(C), branch-circuit conductors supplying household ranges rated 8¾ kW or more must have a minimum ampacity of 40 amperes.
Formulas to Know
Conduit Fill % (single conductor)
Max fill = 53% of conduit cross-sectional area (1 conductor)Conduit Fill % (2 conductors)
Max fill = 31% of conduit cross-sectional area (exactly 2 conductors)Conduit Fill % (>2 conductors)
Max fill = 40% of conduit cross-sectional area (more than 2 conductors)Conductor Cross-Sectional Area Used
Fill area used = π × (conductor OD / 2)² [sum for all conductors, compare to allowed %]Allowable Fill Area
Allowable area = (Fill % / 100) × π × (raceway ID / 2)²Power (single-phase)
P (watts) = V (volts) × I (amperes) × PFPower (three-phase)
P (watts) = √3 × V_L (line volts) × I_L (line amperes) × PFOhm's Law
V = I × R → I = V / R → R = V / IVoltage Drop (single-phase, copper)
VD = (2 × K × I × L) / CM [K = 12.9 for copper, L = one-way length in ft, CM = circular mils]Minimum EGC Size Check (flexible cord)
EGC ≥ 18 AWG AND EGC ≥ circuit conductor size (per NEC 250.122(E))