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

Passing score

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%

Electrical Services, Service Equipment, and Separately Derived Systems 8 Q · 13%

Electrical Feeders 3 Q · 5%

Branch Circuit Calculations and Conductors 10 Q · 17%

Electrical Wiring Methods and Electrical Materials 9 Q · 15%

Electrical Equipment and Devices 10 Q · 17%

Motors and Generators 4 Q · 7%

Electrical Control Devices and Disconnecting Means 3 Q · 5%

Special Occupancies, Equipment, and Conditions 8 Q · 13%

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 400.50

Type 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 400.50

Mandatory 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 90.3

NEC 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 90.3

Continuous 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 Load

Minimum Conductor Ampacity – Multiple Receptacles for Portable LoadsAmpacity ≥ Branch-Circuit Rating

Minimum Branch-Circuit Rating – Household Range ≥ 8¾ kWBranch-Circuit Rating ≥ 40 A

Minimum Free Conductor at BoxFree Length ≥ 150 mm (6 in.) from raceway/cable sheath emergence point

Minimum Burial Depth – General Location Direct-Buried CableCover ≥ 600 mm (24 in.)

Minimum Burial Depth – Residential GFCI-Protected ≤120 V Direct-Buried CableCover ≥ 300 mm (12 in.)

Minimum Edge Distance – Bored Holes in Wood MembersEdge of hole to edge of wood ≥ 32 mm (1-1/4 in.)

Maximum Vertical Support Interval – 18 AWG–8 AWG Copper in Vertical RacewaySupport interval ≤ 100 ft

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