Exam Cheat Sheet · Quick Reference
Texas - Maintenance 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, Calculations, Theory, and Plans
5 Q · 8%
Branch-circuit, feeder, and service load calculations using demand factors and unit loadsGrounding and bonding requirements including electrode systems, conductor sizing, and bonding jumpersOvercurrent protection device ratings, locations, and conductor protection rulesNEC code arrangement, mandatory vs. permissive language, and authority having jurisdiction enforcementGFCI and AFCI protection requirements by location and occupancy typeDwelling unit and non-dwelling receptacle and lighting outlet placement requirementsService entrance conductor sizing, clearances, disconnecting means ratings, and overcurrent protectionUnits of measurement, voltage standards, and rounding rules for electrical calculations
Electrical Services, Service Equipment, and Separately Derived Systems
8 Q · 13%
Service conductor types, sizing, and ampacity requirements (overhead and underground)Service disconnecting means: location, rating, number, and groupingOvercurrent protection for service conductors and equipment (including ground-fault protection)Grounding and bonding of service-supplied AC systems (grounding electrode system, main bonding jumper, grounding electrode conductor sizing)Separately derived systems: grounding, bonding, and system bonding jumper requirementsService entrance conductor wiring methods, clearances, and physical protectionSwitchboards, switchgear, and panelboards used as service equipment (ratings, overcurrent protection, grounding, markings)Surge-protective devices and emergency disconnects for services
Electrical Feeders
3 Q · 5%
Minimum feeder conductor ampacity for continuous and noncontinuous loads (125% rule)Feeder overcurrent protection requirements and ratingsFeeder load calculations including demand factors for dwelling units, multifamily, and commercial occupanciesFeeder conductor size and ampacity correction/adjustment factorsGround-fault protection of equipment for feeders rated 1000 amperes or moreFeeder equipment grounding conductor and grounded conductor requirementsSurge-protective device (SPD) requirements for feeders supplying dwelling and sleeping unitsFeeder conductor identification for grounded, ungrounded, and equipment grounding conductors
Branch Circuit Calculations and Conductors
10 Q · 17%
Minimum conductor ampacity and sizing for branch circuits (continuous vs. noncontinuous loads, 125% rule)Overcurrent protection ratings and sizing for branch circuits (Articles 210.20, 240.4, 240.6)Conductor ampacity tables and correction/adjustment factors (Tables 310.16, 310.17, ambient temperature and bundling derating)GFCI protection requirements by location for dwelling and non-dwelling occupancies (Article 210.8)AFCI protection requirements by occupancy and location (Article 210.12)Branch circuit load calculations for dwelling and non-dwelling units (Articles 220.41, 220.42, demand factors)Multiwire branch circuit requirements including disconnecting means and line-to-neutral loads (Article 210.4)Branch circuit ratings, permissible loads, and receptacle ratings by circuit size (Articles 210.18–210.24)
Electrical Wiring Methods and Electrical Materials
9 Q · 15%
Conductor ampacity tables and temperature rating correction factorsPhysical protection of cables and raceways through and parallel to framing membersUnderground installation requirements and minimum burial depthsPermitted and prohibited uses of cable types (NM, NMC, AC, MC, MI, SE, USE, UF)Securing and supporting intervals for cables and racewaysConductor insulation types, markings, and application requirementsWiring in ducts, plenums, and air-handling spacesProtection against corrosion and dissimilar metals in raceways and fittings
Electrical Equipment and Devices
10 Q · 17%
Switch types, ratings, and permitted uses (Articles 404.14, 404.11)Receptacle installation requirements, grounding, and replacement rules (Article 406)Panelboard, switchboard, and switchgear installation and overcurrent protection (Article 408)Motor circuit conductors, overload protection, and disconnecting means (Article 430)Luminaire installation locations, support, grounding, and wiring requirements (Article 410)Air-conditioning and refrigerating equipment branch circuits, disconnecting means, and overload protection (Article 440)Transformer installation, overcurrent protection, and vault requirements (Article 450)Generator installation, overcurrent protection, and disconnecting means (Article 445)
Motors and Generators
4 Q · 7%
Motor branch-circuit conductor sizing and ampacity requirements (430.22, 430.24)Motor branch-circuit short-circuit and ground-fault protective device ratings and types (430.52, Table 430.52(C)(1))Motor overload protection requirements and trip current percentages (430.32)Motor disconnecting means types, location, and current rating requirements (430.102, 430.109, 430.110)Motor controller ratings, markings, and application requirements (430.83, 430.8)Generator installation requirements including overcurrent protection, conductor ampacity, and disconnecting means (445.12, 445.13, 445.18)Motor nameplate markings and locked-rotor code letters (430.7, Table 430.7(B))Several motors on one branch circuit and feeder protection requirements (430.53, 430.62)
Electrical Control Devices and Disconnecting Means
3 Q · 5%
Switch connection requirements and grounded conductor rules (Article 404.2)Rating and use of switches for specific load types (Article 404.14)Motor disconnecting means location, type, and rating requirements (Article 430, Part IX)Service disconnecting means requirements including location, rating, and number of disconnects (Article 230, Part VI)Circuit breaker and switch enclosure requirements for damp/wet locations and accessibility (Articles 404.3, 404.4, 404.8)Motor controller types, ratings, and disconnecting means (Articles 430.83, 430.109, 430.111)Panelboard and switchboard overcurrent protection and disconnecting requirements (Article 408)Industrial control panel disconnecting means and overcurrent protection (Article 409)
Special Occupancies, Equipment, and Conditions
8 Q · 13%
Classification of hazardous locations by Class (I, II, III) and Division (1 and 2)Protection techniques for hazardous classified locations (explosionproof, dust-ignitionproof, intrinsic safety, purged/pressurized, etc.)Wiring methods permitted in Class I, II, and III Division 1 and 2 locationsSealing and drainage requirements for conduit and cable systems in hazardous locationsEquipment marking requirements including class, division, material group, and temperature class (T codes)Grounding and bonding requirements in hazardous classified locationsSpecial occupancy requirements for commercial garages, aircraft hangars, motor fuel dispensing facilities, and bulk storage plantsIntrinsically safe systems installation, separation, and identification requirements
Key Distinctions
Type SHD CablevsType G Cable
Type SHD is rated 2001–25,000 V with individually shielded power conductors, while Type G is rated only 2001–5000 V and lacks individual conductor shielding.
Table 400.50Type SHD CablevsType SH Cable
Type SHD has individual shields on each power conductor, whereas Type SH has only an overall (single) shield around all conductors.
Table 400.50Mandatory RulevsNon-Mandatory Rule
Mandatory rules use 'shall' or 'shall not' to require or prohibit specific actions, while non-mandatory (permissive/explanatory) rules do not carry that obligatory language.
NEC 90.5(A)NEC Chapters 1–4vsNEC Chapters 5–7
Chapters 1–4 apply generally to all installations, while Chapters 5–7 apply only to special occupancies, equipment, or conditions and may supplement or modify Chapters 1–4.
NEC 90.3NEC Chapter 8 (Communications)vsNEC Chapters 1–7
Chapter 8 covers communications systems and is NOT subject to Chapters 1–7 unless those chapters are specifically referenced within Chapter 8.
Article 90.3Continuous LoadvsNoncontinuous Load
Continuous loads require conductors sized at 125% of their amperage, whereas noncontinuous loads require conductors sized at only 100% of their amperage.
NEC 210.19(A)(1)Grounded Conductor 6 AWG or SmallervsGrounded Conductor 4 AWG or Larger
Conductors 6 AWG or smaller must have a continuous white or gray outer finish (or three stripes), while conductors 4 AWG or larger may alternatively be identified at terminations only with white or gray marking at the time of installation.
NEC 200.6(A)Direct-Buried Cable (General Location)vsDirect-Buried Cable (Residential GFCI-Protected, ≤120 V)
General-location direct-buried cables require a minimum cover of 600 mm (24 in.), while residential GFCI-protected branch circuits rated 120 V or less require only 300 mm (12 in.) of cover.
NEC Table 300.5(A)Multiwire Branch CircuitvsStandard (Two-Wire) Branch Circuit
A multiwire branch circuit must be provided with a means to simultaneously disconnect ALL ungrounded conductors at the origin, a requirement not imposed on standard two-wire circuits.
NEC 210.4(B)NEC Purpose (90.1)vsNEC Scope (90.2)
Article 90.1 defines the purpose (practical safeguarding of persons and property from electrical hazards), while Article 90.2 defines the scope (what installations the NEC does and does not cover).
NEC 90.2(A)NEC-Covered InstallationsvsNEC-Excluded Installations
The NEC covers most electrical installations including mobile homes and RVs, but explicitly excludes ships, watercraft other than floating buildings, railway rolling stock, aircraft, and most automotive vehicles.
NEC 90.2(D)Branch-Circuit Conductor Ampacity (Receptacles for Portable Loads)vsBranch-Circuit Conductor Ampacity (Household Ranges ≥8¾ kW)
Conductors supplying multiple receptacles for portable cord-and-plug loads must have ampacity not less than the branch-circuit rating, while ranges of 8¾ kW or more require a minimum branch-circuit rating of 40 amperes.
NEC 210.19(C)Key Terms
Purpose of the NEC (NEC 90.1(A)) NEC 90.2(A)
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.
NEC Mandatory Rule (NEC 90.5(A)) NEC 90.5(A)
A rule that specifically requires or prohibits an action, always identified by the use of the terms 'shall' or 'shall not'.
NEC Chapter Structure (NEC 90.3) NEC 90.3
The NEC is organized into an introduction plus nine chapters; Chapters 1–4 apply generally, Chapters 5–7 cover special conditions, Chapter 8 covers communications, and Chapter 9 consists of tables.
Grounded Conductor Continuity (NEC 200.2(B)) NEC 200.2(B)
The continuity of a grounded conductor shall not depend on a connection to a metal enclosure, raceway, or cable armor.
Neutral Conductor Use Restriction (NEC 200.4(A)) NEC 200.4(A)
A neutral (grounded) conductor shall not be used for more than one branch circuit or more than one multiwire branch circuit unless specifically permitted elsewhere in the Code.
Same-Raceway Rule (NEC 300.3(B)) NEC 300.3(B)
All conductors of the same circuit, including the grounded conductor and equipment grounding conductors, must be contained within the same raceway, cable, or conduit unless otherwise permitted.
Induction Heating Prevention in Ferrous Raceways (NEC 300.20(A)) NEC 300.20(A)
When AC conductors are installed in ferrous metal enclosures or raceways, all phase conductors, the grounded conductor, and equipment grounding conductors must be grouped together to prevent heating by induction.
Minimum Free Conductor Length (NEC 300.14) NEC 300.14
At least 150 mm (6 in.) of free conductor, measured from where it emerges from the raceway or cable sheath, must be left at each outlet, junction, and switch point.
Edge Distance for Bored Holes (NEC 300.4(A)(1)) NEC 300.4(A)(1)
When cables pass through bored holes in wood members, the edge of the hole must be at least 32 mm (1-1/4 in.) from the edge of the wood member to protect against nail or screw damage.
Vertical Conductor Support Interval (NEC Table 300.19(A)) NEC Table 300.19(A)
Copper conductors 18 AWG through 8 AWG in vertical raceways must be supported at intervals not exceeding 100 feet.
GFCI Protection – Class A (NEC 210.8) NEC 210.8
A listed Class A GFCI device is required for personnel protection in locations specified by NEC 210.8, including bathrooms, kitchens, garages, and outdoor areas of dwelling units.
Standard Branch-Circuit Ratings (NEC 210.18) NEC 210.18
The NEC recognizes standard multioutlet branch-circuit ratings of 10, 15, 20, 30, 40, and 50 amperes.
Maximum Voltage – Dwelling Unit Branch Circuits (NEC 210.6(A)) NEC 210.6(A)
In dwelling units, voltage between conductors supplying cord-and-plug-connected loads of 1440 VA or less, or luminaires, shall not exceed 120 volts nominal.
Type SHD Portable Power Feeder Cable (NEC Table 400.50) Table 400.50
A portable power feeder cable rated 2001–25,000 V featuring three individually insulated, taped, and shielded round power conductors plus grounding conductors.
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, gray outer finish, or three continuous white or gray stripes; blue or black are not permitted.
Multiwire Branch Circuit Disconnect (NEC 210.4(B)) NEC 210.4(B)
Each multiwire branch circuit must have a means at its origin to simultaneously disconnect all ungrounded conductors.
Formulas to Know
Minimum Branch-Circuit Conductor Ampacity (Mixed Loads)
Ampacity ≥ (125% × Continuous Load) + (100% × Noncontinuous Load)Minimum Branch-Circuit Conductor Ampacity (Continuous Load Only)
Ampacity ≥ 125% × Continuous LoadMinimum Conductor Ampacity – Multiple Receptacles for Portable Loads
Ampacity ≥ Branch-Circuit RatingMinimum Branch-Circuit Rating – Household Range ≥ 8¾ kW
Branch-Circuit Rating ≥ 40 AMinimum Free Conductor at Box
Free Length ≥ 150 mm (6 in.) from raceway/cable sheath emergence pointMinimum Burial Depth – General Location Direct-Buried Cable
Cover ≥ 600 mm (24 in.)Minimum Burial Depth – Residential GFCI-Protected ≤120 V Direct-Buried Cable
Cover ≥ 300 mm (12 in.)Minimum Edge Distance – Bored Holes in Wood Members
Edge of hole to edge of wood ≥ 32 mm (1-1/4 in.)Maximum Vertical Support Interval – 18 AWG–8 AWG Copper in Vertical Raceway
Support interval ≤ 100 ft