Exam Cheat Sheet · Quick Reference

Texas - Journeyman Electrician - NEC Knowledge Portion

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

130 min

Administered by

PSI Services Contractor

Format

Reference materials allowed

Texas State Portion 59 questions

Definitions, Theory, and Plans 3 Q · 5%

Electrical Services, Service Equipment, and Separately Derived Systems 6 Q · 11%

Electrical Feeders 3 Q · 5%

Branch Circuits and Conductors 10 Q · 18%

Electrical Wiring Methods and Electrical Materials 10 Q · 18%

Electrical Equipment and Devices 10 Q · 18%

Motors and Generators 5 Q · 9%

Electrical Control Devices and Disconnecting Means 1 Q · 2%

Special Occupancies, Equipment, and Conditions 6 Q · 11%

Renewable Energy Technologies 2 Q · 4%

Key Distinctions

Class I, Division 1vsClass I, Division 2

Division 1 locations have flammable gases or vapors present under normal operating conditions, while Division 2 locations normally confine hazardous materials in closed containers that can escape only upon accidental rupture.

NEC 500.5(B)(2)

Grounded Conductor Identification (6 AWG or smaller)vsEquipment Grounding Conductor Identification

Grounded conductors 6 AWG or smaller must have a continuous white or gray outer finish (or three white/gray stripes), while green is reserved exclusively for equipment grounding conductors.

NEC 200.6(A)

Conductor Ampacity (Table 310.16)vsMaximum Overcurrent Protection (NEC 240.4(D))

A 12 AWG THWN copper conductor has a Table 310.16 ampacity of 25 amperes, but NEC 240.4(D) limits overcurrent protection for 12 AWG to 20 amperes.

NEC Table 310.16

Continuous Load Conductor SizingvsNoncontinuous Load Conductor Sizing

Conductors supplying continuous loads must be sized at 125% of the continuous load plus 100% of any noncontinuous load, whereas noncontinuous loads alone require only 100% of the load for ampacity.

NEC 210.19(A)(1)

Direct-Buried Cable — General LocationvsDirect-Buried Cable — GFCI-Protected Residential 120V ≤20A

General-location direct-buried cables require a minimum cover of 600 mm (24 in.), while residential branch circuits rated 120V or less with GFCI protection require only 300 mm (12 in.).

NEC Table 300.5(A)

Multiwire Branch Circuit Neutral IdentificationvsMultiwire Branch Circuit Disconnecting Means

Neutral conductors must be identified or grouped with their corresponding ungrounded conductors at least once per enclosure, while the disconnecting means must simultaneously open all ungrounded conductors at the origin.

NEC 200.4(B), 210.4(D)

Standard Branch-Circuit Ratings (Multioutlet)vsIndividual Branch-Circuit Ratings

Multioutlet (other-than-individual) branch circuits are limited to standard ratings of 10, 15, 20, 30, 40, and 50 amperes, while individual branch circuits are not restricted to these standard ratings.

NEC 210.18

Flexible Cord EGC Sizing (NEC 400.23)vsRaceway/Cable EGC Sizing (NEC 250.122 Table)

Equipment grounding conductors in flexible cords may be as small as 18 AWG per NEC 400.23, whereas NEC 250.122 Table normally requires a minimum of 14 AWG for raceway/cable installations.

NEC 400.23

Motor FLC from NEC Table 430.248vsMotor Nameplate Current

NEC 430.6(A)(1) requires branch-circuit sizing for single-phase AC motors to use Table 430.248 full-load current values, not the motor nameplate markings.

NEC 430.6(A)(1) and Table 430.248

Vertical Raceway Support — Copper 18 AWG–1/0 AWGvsVertical Raceway Support — Aluminum/Copper-Clad Aluminum

Copper conductors 18 AWG through 1/0 AWG in vertical raceways must be supported at maximum 30 m (100 ft) intervals, while aluminum or copper-clad aluminum conductors in the same size range are permitted up to 60 m (200 ft) intervals.

NEC Table 300.19(A)

Grounded Conductor ID — Same Voltage SystemvsGrounded Conductor ID — Multiple Voltage Systems in Same Raceway

A single white or gray finish satisfies identification for grounded conductors on one voltage system, but when conductors of different nominal voltage systems share a raceway each grounded conductor must additionally be identified by its nominal voltage system.

NEC 200.6(A)

Flexible Cord Splice RulevsParallel Conductor Raceway Rule

Flexible cords must be installed in continuous lengths without splice or tap (NEC 400.13), whereas conductors run in parallel are permitted provided each raceway contains all circuit conductors of that set.

NEC 400.13

Key Terms

Continuous Load — 125% Conductor Sizing (NEC 210.19(A)(1)) NEC 210.19(A)(1)

Branch-circuit conductors must have an ampacity not less than the noncontinuous load plus 125% of the continuous load.

Small-Appliance Branch Circuits Required — Dwelling Units (NEC 210.11(C)(1)) NEC 210.11(C)(1)

Dwelling units must have two or more 20-ampere small-appliance branch circuits for receptacle outlets specified in NEC 210.52(B).

Maximum Dwelling-Unit Voltage for Cord-and-Plug Loads (NEC 210.6(A)) NEC 210.6(A)

In dwelling units, voltage shall not exceed 120 volts nominal between conductors supplying cord-and-plug-connected loads of 1,440 VA or less, or less than 1/4 hp.

Household Range Minimum Branch-Circuit Rating (NEC 210.19(C)) NEC 210.19(C)

Household ranges rated 8-3/4 kW or more require a minimum branch-circuit rating of 40 amperes.

AFCI Protection — Dwelling Unit Bedrooms (NEC 210.12(B)) NEC 210.12(B)

All 120-volt, single-phase, 10-, 15-, and 20-ampere branch circuits supplying outlets in dwelling unit bedrooms must be protected by any of the means described in NEC 210.12(A)(1) through (A)(6).

Multiwire Branch Circuit Simultaneous Disconnect (NEC 210.4(B)) 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 circuit originates.

Neutral Grouping in Enclosures (NEC 200.4(B) / 210.4(D)) NEC 200.4(B), 210.4(D)

Where multiple neutrals of different circuits share an enclosure, each grounded conductor must be identified or grouped with its corresponding ungrounded conductors at least once within that enclosure.

Free Conductor Length at Outlets (NEC 300.14) NEC 300.14

At least 150 mm (6 in.) of free conductor, measured from where it emerges from its raceway or cable sheath, must be left at each outlet, junction, and switch point.

Cable Protection in Bored Holes (NEC 300.4(A)(1)) NEC 300.4(A)(1)

Holes bored through wood members must be at least 32 mm (1-1/4 in.) from the edge of the wood member; otherwise, a steel plate or bushing is required.

All-Conductors-Same-Raceway Rule (NEC 300.3(B)(1)) NEC 300.3(B)(1)

All conductors of the same circuit must be in the same raceway, cable, or trench, except in approved parallel installations where each raceway contains all circuit conductors.

Single-Phase AC Motor FLC Table (NEC 430.6(A)(1)) NEC 430.6(A)(1) and Table 430.248

Full-load current values for single-phase AC motors must be taken from NEC Table 430.248, not from the motor nameplate.

Flexible Cord EGC Minimum Size (NEC 400.23) NEC 400.23

Equipment grounding conductors in flexible cords may be as small as 18 AWG copper, matching the cord's circuit conductors, rather than the 14 AWG minimum that NEC Table 250.122 would otherwise require.

Class I, Division 2 Location (NEC 500.5(B)(2)) NEC 500.5(B)(2)

A location where volatile flammable gases or vapors are normally confined within closed containers and can escape only upon accidental rupture or breakdown.

12 AWG THWN Ampacity (NEC Table 310.16) NEC Table 310.16

A 12 AWG copper THWN conductor has a table ampacity of 25 amperes at 30°C ambient; the 20-ampere value is the overcurrent protection limit under NEC 240.4(D), not the ampacity.

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 or gray outer finish, or three continuous white or gray stripes; green is not permitted.

Standard Branch-Circuit Ratings (NEC 210.18) NEC 210.18

Branch circuits other than individual branch circuits shall be rated at 10, 15, 20, 30, 40, or 50 amperes — 25 amperes is not a recognized standard rating.

Formulas to Know

Minimum Conductor Ampacity — Continuous + Noncontinuous LoadAmpacity ≥ (Noncontinuous Load) + 1.25 × (Continuous Load)

Branch-Circuit Overcurrent Device Size — Continuous LoadOCPD Rating ≥ 1.25 × (Continuous Load) + 1.0 × (Noncontinuous Load)

Single-Phase PowerP (W) = V (volts) × I (amps) × PF

Three-Phase PowerP (W) = √3 × V_L (volts) × I_L (amps) × PF

Voltage Drop (single-phase)VD = (2 × K × I × L) / CM [K = 12.9 for copper, L = one-way length in feet, CM = circular mils]

Percent Voltage Drop% VD = (VD / V_source) × 100

Ohm's LawV = I × R (also: I = V/R, R = V/I)

Motor Full-Load Current (single-phase) — sizing multiplierBranch-circuit conductor ampacity ≥ 1.25 × FLC (from Table 430.248)

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