Exam Cheat Sheet · Quick Reference

Texas - Residential Appliance Installer

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

70%

Exam time

240 min

Administered by

PSI Services Contractor

Format

Reference materials allowed

Texas State Portion 80 questions

Definitions, Calculations, and Theory 12 Q · 15%

Code DefinitionsGeneral Electrical Calculations

GFCI Protection and Equipment Grounding and Bonding 15 Q · 19%

GFCI ProtectionEquipment Grounding and BondingEquipotential Bonding

Electrical Wiring Methods and Electrical Materials 10 Q · 12%

RacewaysBoxes and EnclosuresCables, Flexible Cords, and Conductors

Electrical Equipment and Devices 15 Q · 19%

Receptacles, Switches, and DevicesAppliancesWorkspace ClearanceUtilization Equipment

Motors 5 Q · 6%

Electric Motors

Electrical Control Devices and Disconnecting Means 5 Q · 6%

Controllers, Switches, and Disconnects

Swimming Pool, Spas and Fountain Equipment 18 Q · 22%

Pool Equipment HeaterPool CoverPool LuminairesPumpsVertical ClearanceHorizontal ClearanceHot Tubs and SpasFountain Equipment

Key Distinctions

Mandatory NEC Rules ('shall'/'shall not')vsPermissive NEC Rules

Mandatory rules use 'shall' or 'shall not' and identify actions specifically required or prohibited, while permissive rules allow but do not require certain actions.

NEC 90.5(A)

Grounded Conductor Terminal Color (White/Silver)vsEquipment Grounding Conductor Color (Green/Green-Yellow)

Grounded (neutral) conductor terminals are identified by white or silver color, while equipment grounding conductors in flexible cords are identified by continuous green or green with one or more yellow stripes.

NEC 200.9

GFCI Requirements — Dwelling Units (NEC 210.8(A))vsGFCI Requirements — Other Than Dwelling Units (NEC 210.8(B))

Dwelling units require GFCI for 125V–250V receptacles in bathrooms, garages, outdoors, crawl spaces, basements, kitchens, and laundry areas; non-dwelling locations require GFCI for rooftops, outdoors, and other specified areas, with amperage limits of 50A single-phase and 100A three-phase.

NEC 210.8(A)

Conduit Fill — 2 Conductors (31%)vsConduit Fill — 3 or More Conductors (40%)

When only 2 conductors are installed in a conduit, maximum fill is 31% of cross-sectional area, whereas 3 or more conductors allows up to 40%.

Table 1, Chapter 9

Standard Conduit Fill (≤40%)vsNipple Conduit Fill (60%)

Standard conduit fill is limited to 31–40% depending on conductor count, but conduit nipples not exceeding 600 mm (24 in.) between boxes are permitted to be filled to 60% of total cross-sectional area.

Table 1, Chapter 9

NEC Chapters 1–4 (General)vsNEC Chapter 8 (Communications Systems)

Chapters 1–4 apply generally to all electrical installations, while Chapter 8 covers communications systems and is NOT subject to Chapters 1–7 except where specifically referenced in Chapter 8.

Article 90.3

NEC Chapters 1–4 (General)vsNEC Chapters 5, 6, and 7 (Special)

Chapters 1–4 apply to all installations broadly, while Chapters 5, 6, and 7 apply to special occupancies, equipment, or conditions and may supplement or modify Chapters 1–4.

Article 90.3

GFCI Exception — Premises Security System ReceptaclesvsGFCI Exception — Weight-Supporting Ceiling Receptacles (WSCR)

A receptacle supplying only a permanently installed premises security system may omit GFCI to prevent nuisance tripping from disabling security; listed WSCRs used with compatible WSAFs may also omit GFCI unless they include an integral general-purpose convenience receptacle.

NEC 210.8(A) Exception No. 2

SI (Metric) Units — Measurement of Preference in NECvsInch-Pound Units — Secondary Measurement in NEC

SI units appear first in the NEC as the measurement system of preference per 90.9(A), with inch-pound units immediately following in parentheses, and when a difference exists between the two, the inch-pound measurement governs.

NEC 90.9(A), 90.9(B)

Grounded Conductor Continuity (Must Be Direct)vsGrounded Conductor via Metal Enclosure/Raceway (Not Permitted)

The continuity of a grounded conductor must be maintained through direct electrical connections and shall not depend on connection to a metal enclosure, raceway, or cable armor.

NEC 200.2(B)

Screw Shell Device — Grounded Conductor TerminalvsScrew Shell Device — Ungrounded Conductor Terminal

For screw shell devices, the terminal connected to the screw shell is designated for the grounded conductor, ensuring correct polarity.

NEC 200.10(C)

GFCI for Receptacles (210.8)vsGFCI for Lighting Outlets in Crawl Spaces (210.8(C))

NEC 210.8 requires GFCI for receptacles in numerous specified locations, while 210.8(C) separately requires GFCI for lighting outlets not exceeding 120 volts installed in crawl spaces.

NEC 210.8(C)

Key Terms

Purpose of the NEC (NEC 90.2(A)) NEC 90.2(A)

The primary purpose of the National Electrical Code is 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 Code Arrangement — General Chapters (Article 90.3) Article 90.3

NEC Article 90.3 establishes that Chapters 1 through 4 apply generally to all electrical installations, Chapters 5–7 cover special occupancies/equipment/conditions, Chapter 8 covers communications systems independently, and Chapter 9 consists of applicable tables.

Mandatory Rule Language (Article 90.5(A)) NEC 90.5(A)

Per NEC Article 90.5(A), mandatory rules that identify actions specifically required or prohibited are characterized by the terms 'shall' or 'shall not.'

Metric System of Preference (NEC 90.9(A)) NEC 90.9(A), 90.9(B)

NEC 90.9(A) designates the International System of Units (SI) as the metric measurement system of preference, with SI units appearing first and inch-pound units in parentheses.

GFCI Protection Locations — Dwelling Units (NEC 210.8(A)) NEC 210.8(A)

NEC 210.8(A) requires GFCI protection for all 125V–250V receptacles rated 50A or less supplied by single-phase branch circuits rated 150V or less to ground in bathrooms, garages, outdoors, crawl spaces, basements, kitchens, areas within 6 ft of sinks, boathouses, bathtub/shower areas, laundry areas, and indoor damp/wet locations.

GFCI Protection — Non-Dwelling Units (NEC 210.8(B)) NEC 210.8(B)

NEC 210.8(B) requires GFCI protection for receptacles in non-dwelling locations including rooftops and outdoors, with limits of 50A for single-phase and 100A for three-phase branch circuits rated 150V or less to ground.

GFCI for Specific Appliances (NEC 210.8(D)) NEC 210.8(D)

NEC 210.8(D) requires GFCI protection for branch circuits or outlets supplying specific appliances rated 150V or less to ground and 60A or less, including dishwashers, electric ranges, wall-mounted ovens, clothes dryers, microwave ovens, and sump pumps.

Grounded Conductor Continuity (NEC 200.2(B)) NEC 200.2(B)

NEC 200.2(B) prohibits the continuity of a grounded conductor from depending on connection to a metal enclosure, raceway, or cable armor; continuity must be maintained through direct electrical connections.

Grounded Conductor Identification — 6 AWG or Smaller (NEC 200.6(A)) NEC 200.6(A)

NEC 200.6(A) requires grounded conductors of 6 AWG or smaller to be identified by a continuous white or gray outer finish.

Equipment Grounding Conductor — Flexible Cord (NEC 400.23) NEC 400.23

NEC 400.23 requires equipment grounding conductors in flexible cords to be identified by a continuous green color or continuous green with one or more yellow stripes, and these colors shall not be used for any other purpose.

Conduit Fill — Nipples (Table 1, Chapter 9, Note 4) Table 1, Chapter 9, Note (4)

Per NEC Chapter 9, Table 1, Note 4, conduit nipples not exceeding 600 mm (24 in.) between boxes are permitted to be filled to 60% of their total cross-sectional area.

Parallel Conductor Installation Exception (NEC 300.3(B)(1)) NEC 300.3(B)(1)

NEC 300.3(B)(1) permits conductors to be run in parallel per 310.10(G), with the requirement that all circuit conductors be in the same raceway applied separately to each portion of the paralleled installation rather than all conductors in a single raceway.

GFCI — Readily Accessible Location (NEC 210.8) NEC 210.8

NEC 210.8 requires a listed Class A GFCI to be installed in a readily accessible location so it can be reached quickly for operation, testing, renewal, or inspection without climbing over or removing obstacles.

Grounded Conductor Terminal Identification — Receptacles (NEC 200.10(B)) NEC 200.10(B)

NEC 200.10(B) requires receptacle terminals intended for the grounded conductor to be identified by a metal or metal coating that is white or silver in color, or by the word 'white' or the letter 'W' adjacent to the terminal.

GFCI for Crawl Space Lighting Outlets (NEC 210.8(C)) NEC 210.8(C)

NEC 210.8(C) requires GFCI protection for lighting outlets not exceeding 120 volts installed in crawl spaces to guard against ground faults in potentially damp environments.

NEC Scope — Exclusions (Article 90.2(B)) Article 90.2(D)

NEC Article 90.2(B) excludes from Code coverage installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, and automotive vehicles other than mobile homes and recreational vehicles.

Formulas to Know

Conduit Fill Area (Single Conductor)Max fill = 53% of conduit internal cross-sectional area (1 conductor)

Conduit Fill Area (2 Conductors)Max fill = 31% of conduit internal cross-sectional area (2 conductors)

Conduit Fill Area (3 or More Conductors)Max fill = 40% of conduit internal cross-sectional area (3+ conductors)

Conduit Nipple Fill (≤24 in.)Max fill = 60% of conduit internal cross-sectional area (nipple ≤ 600 mm / 24 in.)

Conductor Cross-Sectional AreaArea = π × (diameter / 2)²

Total Conduit Fill Area UsedTotal fill area = Sum of cross-sectional areas of all conductors installed

Fill Percentage CheckFill % = (Total conductor area ÷ Conduit interior area) × 100 — must not exceed allowed %

Ohm's Law — CurrentI (amperes) = V (volts) ÷ R (ohms)

Power FormulaP (watts) = V (volts) × I (amperes)

Branch Circuit LoadLoad (VA) = Voltage × Amperage; must not exceed 80% of breaker rating for continuous loads

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