Exam Cheat Sheet · Quick Reference
Texas - Residential Wireman 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
80
Passing score
70%
Exam time
240 min
Administered by
PSI Services Contractor
Format
Reference materials allowed
Texas State Portion 80 questions
Definitions, Calculations, Theory, and Plans
8 Q · 10%
Branch-circuit, feeder, and service load calculations using demand factorsDwelling unit load calculations including lighting, small appliance, and laundry circuitsNEC code arrangement, mandatory vs. permissive rules, and enforcement authorityGrounding electrode system types, sizing, and installation requirementsOvercurrent protection sizing and location requirements for conductors and equipmentGFCI and AFCI protection requirements by location and occupancy typeDwelling unit receptacle and lighting outlet placement requirementsUnits of measurement, nominal voltages, and rounding conventions used in calculations
Electrical Services, Service Equipment, and Separately Derived Systems
16 Q · 20%
Service conductor clearances and installation requirements (overhead and underground)Service disconnecting means location, rating, and maximum numberService entrance conductor sizing, ampacity, and permitted wiring methodsService equipment overcurrent protection and ground-fault protection requirementsGrounding and bonding of service-supplied AC systems and service equipmentGrounding electrode system types, installation, and conductor sizingSeparately derived system grounding, bonding jumpers, and grounding electrode connectionsSurge-protective devices and emergency disconnects for dwelling services
Electrical Feeders
7 Q · 9%
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 occupanciesFeeder conductor sizing using ampacity correction and adjustment factorsGround-fault protection of equipment for feeder disconnects rated 1000 amperes or moreSurge-protective device (SPD) requirements for feeders supplying dwelling and care facility unitsFeeder conductor and equipment grounding conductor identification and labelingOutside feeders: clearances, disconnecting means, number of supplies, and ratings for buildings supplied by feeders
Branch Circuit Calculations and Conductors
14 Q · 18%
Minimum conductor ampacity and sizing for continuous and noncontinuous loads (210.19, 215.2)Overcurrent protection ratings for branch circuits including continuous load calculations (210.20, 240.4)GFCI protection requirements by location for dwelling and non-dwelling occupancies (210.8)AFCI protection requirements and approved means of protection for dwelling units (210.12)Branch circuit ratings and permissible loads by circuit size (210.18, 210.23, 210.24)Dwelling unit load calculations including lighting, small-appliance, and cooking appliance loads (220.41, 220.52, 220.55)Conductor ampacity tables, temperature correction, and adjustment factors for more than three current-carrying conductors (310.15, 310.16)Required receptacle outlet placement in dwelling units including kitchens, bathrooms, garages, and outdoor locations (210.52)
Electrical Wiring Methods and Electrical Materials
10 Q · 12%
Conductor types, insulation ratings, and ampacity tables (Articles 310, 402)Physical protection of cables and raceways through framing members and structural elements (Article 300.4)Underground installation requirements and minimum cover depths (Article 300.5)Nonmetallic-sheathed cable (Type NM/NMC) uses, securing, and support intervals (Article 334)Outlet, device, junction, and pull box sizing, fill calculations, and support requirements (Article 314)Armored cable (Type AC) and metal-clad cable (Type MC) uses, bending radius, and securing requirements (Articles 320, 330)Flexible cord and fixture wire types, permitted uses, and ampacity (Articles 400, 402)Corrosion protection, raceway sealing, and wiring in environmental air spaces (Articles 300.6, 300.7, 300.22)
Electrical Equipment and Devices
12 Q · 15%
Switch types, ratings, and permitted uses (AC/DC snap switches, dimmers, knife switches, circuit breakers as switches)Receptacle ratings, grounding types, and termination requirements (CO/ALR, tamper-resistant, weather-resistant, isolated ground)Luminaire installation requirements by location (wet/damp, clothes closets, bathtub/shower areas, recessed)Panelboard and switchboard installation, overcurrent protection, and grounding requirementsMotor branch-circuit conductor sizing and overload protection requirementsDisconnecting means requirements for motors, appliances, air-conditioning equipment, and generatorsTransformer overcurrent protection, installation, and vault requirementsAppliance branch-circuit ratings, GFCI protection requirements, and flexible cord use
Motors and Generators
2 Q · 2%
Motor branch-circuit conductor sizing and ampacity requirements (125% rule, single and multiple motors)Motor overload protection selection, ratings, and placement (separate devices, thermal protectors, trip current percentages)Branch-circuit short-circuit and ground-fault protective device ratings for motors (Table 430.52, fuse and circuit breaker maximums)Motor disconnecting means requirements (type, location, rating, in-sight rule)Motor controller requirements (ratings, markings, horsepower ratings, number of motors served)Motor and controller nameplate marking requirements (locked-rotor code letters, design letters, service factor)Generator installation requirements (overcurrent protection, conductor ampacity, disconnecting means, emergency shutdown)Motor control center requirements (overcurrent protection, grounding, busbar arrangement, marking)
Electrical Control Devices and Disconnecting Means
2 Q · 2%
Switch connection requirements and grounded conductor rules (Article 404.2)Motor disconnecting means location, type, and rating requirements (Article 430, Part IX)Switch and circuit breaker ratings, types, and load control limitations (Article 404.14)Panelboard and switchboard overcurrent protection and installation requirements (Article 408)Motor controller ratings, design, and disconnecting means (Article 430, Parts VII and IX)Switch and enclosure accessibility, mounting height, and position requirements (Article 404.6–404.8)Industrial control panel supply conductor sizing, overcurrent protection, and disconnecting means (Article 409)Enclosure requirements for switches, circuit breakers, and motor controllers in damp/wet locations (Articles 404.4, 408.16, 408.37)
Special Occupancies, Equipment, and Conditions
7 Q · 9%
Classification of hazardous locations (Class I, II, III and Division 1 vs. Division 2)Material group classifications for Class I (Groups A, B, C, D) and Class II (Groups E, F, G)Protection techniques for classified locations (explosionproof, dust-ignitionproof, intrinsically safe, purged/pressurized, nonincendive, etc.)Wiring methods permitted in Class I, II, and III Division 1 and Division 2 locationsSealing and drainage requirements for conduit and cable systems in hazardous locationsEquipment marking requirements including temperature class (T codes), class, division, and groupSpecial occupancy requirements for commercial garages, aircraft hangars, motor fuel dispensing facilities, bulk storage plants, and spray application areasHealth care facility wiring requirements including patient care spaces, essential electrical systems, and isolated power systems
Renewable Energy Technologies
2 Q · 2%
PhotovoltaicsElectric Vehicle Chargers
Key Distinctions
Grounded Conductor (Neutral)vsEquipment Grounding Conductor
Grounded conductors 6 AWG or smaller must be identified by continuous white or gray finish (or three white/gray stripes), while equipment grounding conductors must be identified by continuous green or green with yellow stripes.
NEC 200.6(A)Mandatory NEC RulesvsPermissive NEC Rules
Mandatory rules use the terms 'shall' or 'shall not' to identify required or prohibited actions, whereas permissive rules use different language to indicate acceptable options.
Article 90.5(A)NEC Chapters 1–4vsNEC Chapters 5–7
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 the general requirements.
NEC 90.3Multiwire Branch Circuit (line-to-neutral loads)vsMultiwire Branch Circuit (line-to-line loads)
Multiwire branch circuits shall supply only line-to-neutral loads by default; supplying line-to-line loads is permitted only where the circuit supplies one utilization equipment or all ungrounded conductors are opened simultaneously by the overcurrent device.
NEC 210.4(C)Continuous LoadvsNoncontinuous Load
The minimum branch-circuit conductor ampacity must be not less than 125 percent of the continuous load, while the noncontinuous load is added at 100 percent.
NEC 210.19(A)(1)GFCI-Required Locations in Dwelling UnitsvsNon-GFCI Required Locations in Dwelling Units
Bathrooms, garages, outdoors, crawl spaces, basements, kitchens, laundry areas, boathouses, and indoor damp/wet locations require GFCI protection, while living rooms, bedrooms, and hallways are not listed GFCI-required locations.
NEC 210.8(A)120-Volt Branch Circuit (Dwelling Unit Luminaires)vs277-Volt Branch Circuit (Luminaires)
In dwelling units, voltage supplying luminaire terminals must not exceed 120 volts nominal between conductors; for circuits exceeding 120 volts but not exceeding 277 volts to ground, only medium-base or smaller screw-shell incandescent lampholders are permitted under specific conditions.
NEC 210.6(A)Fixed Wiring (Permanent)vsFlexible Cord
Flexible cords shall not be used as a substitute for the fixed wiring of a structure; fixed wiring is the required permanent wiring method.
NEC 400.12(1)Small-Appliance Branch CircuitvsHousehold Range Branch Circuit
Small-appliance branch circuits require a minimum of two 20-ampere circuits for dwelling unit receptacle outlets, while household ranges rated 8¾ kW or more require a dedicated branch circuit rated at least 40 amperes.
NEC 210.11(C)(1)Autotransformer-Derived Branch Circuit (Permitted)vsAutotransformer-Derived Branch Circuit (Prohibited)
Branch circuits may be derived from autotransformers only if the circuit supplied has a grounded conductor electrically connected to a grounded conductor of the supply system; otherwise they are prohibited.
NEC 210.9Outlet Branch-Circuit AFCI with 14 AWGvsStandard AFCI Protection
When using an outlet branch-circuit-type AFCI with a supplemental arc protection circuit breaker, the maximum wiring length from the overcurrent device to the first outlet is 50 feet for 14 AWG; standard AFCI protection does not carry this length restriction.
NEC 210.12(A)(3)(b)Grounded Conductor ContinuityvsMetal Enclosure/Raceway Continuity
The continuity of a grounded conductor shall not depend on connection to a metal enclosure, raceway, or cable armor; these are separate systems and cannot substitute for proper grounded conductor continuity.
NEC 200.2(B)Key Terms
Purpose of the NEC (NEC 90.1/90.2(A)) NEC 90.2(A)
The practical safeguarding of persons and property from hazards arising from the use of electricity; the Code is not intended as a design specification or instruction manual for untrained persons.
NEC Code Structure (NEC 90.3) NEC 90.3
The NEC is divided into an introduction and nine chapters; Chapters 1–4 apply generally to all installations, while Chapters 5, 6, and 7 apply to special occupancies or conditions.
Mandatory Rules — 'Shall' (NEC 90.5(A)) Article 90.5(A)
Mandatory NEC rules are characterized by the terms 'shall' or 'shall not' and identify actions that are specifically required or prohibited.
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 outer finish, continuous gray outer finish, or three continuous white or gray stripes along their entire length.
Grounded Conductor Continuity (NEC 200.2(B)) NEC 200.2(B)
The continuity of a grounded conductor shall not depend on connection to a metal enclosure, raceway, or cable armor.
Multiple Neutral Conductors — Grouping (NEC 200.4(B)) NEC 200.4(B)
Where more than one neutral conductor is in an enclosure, grounded circuit conductors of each circuit shall be identified or grouped to correspond with their ungrounded conductors using wire markers, cable ties, or similar means.
Multiwire Branch Circuit Disconnecting Means (NEC 210.4(B)) NEC 210.4(B)
Each multiwire branch circuit shall be provided with a means that simultaneously disconnects all ungrounded conductors at the point where the branch circuit originates.
Small-Appliance Branch Circuits (NEC 210.11(C)(1)) NEC 210.11(C)(1)
Two or more 20-ampere small-appliance branch circuits shall be provided for all receptacle outlets in dwelling units as specified by NEC 210.52(B).
GFCI Protection — Dwelling Unit Locations (NEC 210.8(A)) NEC 210.8(A)
GFCI protection is required for all 125-volt through 250-volt receptacles in dwelling unit bathrooms, garages, outdoors, crawl spaces, basements, kitchens, laundry areas, boathouses, bathtub/shower areas, and indoor damp/wet locations.
Branch-Circuit Conductor Ampacity — Continuous Loads (NEC 210.19(A)(1)) NEC 210.19(A)(1)
The minimum branch-circuit conductor ampacity shall be not less than the noncontinuous load plus 125 percent of the continuous load.
Household Range Branch-Circuit Rating (NEC 210.19(C)) NEC 210.19(C)
Branch circuits supplying household ranges rated 8¾ kW or more shall have a minimum branch-circuit rating of 40 amperes.
Conduit Fill — More Than 2 Conductors (Chapter 9, Table 1) Table 1
When more than two conductors or cables are installed in conduit or tubing, the total cross-sectional area shall not exceed 40 percent of the internal cross-sectional area of the conduit.
Flexible Cord — Prohibited Use (NEC 400.12) NEC 400.12(1)
Flexible cords shall not be used as a substitute for the fixed wiring of a structure.
Equipment Grounding Conductor Color — Flexible Cords (NEC 400.23) NEC 400.23
Equipment grounding conductors in flexible cords must be identified by a continuous green color or continuous green with one or more yellow stripes, and this color coding shall not be used for any other purpose.
Portable Power Feeder Cable — Minimum Conductor Size (NEC 400.44(A)) NEC 400.44(A)
Conductors for portable power feeder cables over 2000 volts shall be 6 AWG copper or larger and shall employ flexible stranding.
AFCI — Maximum Wiring Length to First Outlet (NEC 210.12(A)(3)(b)) NEC 210.12(A)(3)(b)
When using an outlet branch-circuit-type AFCI with a supplemental arc protection circuit breaker, the maximum length of 14 AWG branch-circuit wiring from the overcurrent device to the first outlet shall not exceed 50 feet.
Formulas to Know
Branch-Circuit Conductor Ampacity (Continuous + Noncontinuous Load)
Minimum Ampacity = Noncontinuous Load (A) + (Continuous Load (A) × 1.25)Conduit Fill — More Than 2 Conductors
Total conductor cross-sectional area ≤ 0.40 × Internal cross-sectional area of conduitVolt-Amperes (Apparent Power)
VA = Volts × AmperesAmperes from VA and Voltage
Amperes = VA ÷ VoltsOhm's Law — Current
I (Amperes) = V (Volts) ÷ R (Ohms)Ohm's Law — Voltage
V (Volts) = I (Amperes) × R (Ohms)Power (Watts)
P (Watts) = V (Volts) × I (Amperes)Minimum Branch-Circuit Rating — Continuous Load Only
Minimum Rating = Continuous Load (A) × 1.25