Texas Residential Appliance Installer

Key Concepts

Purpose, arrangement, and language of the Code - The purpose of the 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 (90.2(A)). - Compliance plus proper maintenance results in an installation "essentially free from hazard but not necessarily efficient, convenient, or adequate for good service or future expansion of electrical use" (90.2(B)). - The Code is divided into the introduction and nine chapters. Chapters 1–4 apply generally; Chapters 5, 6, and 7 cover special occupancies, special equipment, or other special conditions; Chapter 8 (communications systems) is not subject to Chapters 1 through 7 except where specifically referenced in Chapter 8; Chapter 9 consists of tables applicable as referenced (90.3). - Mandatory rules use "shall" or "shall not" (90.5(A)); permissive rules use "shall be permitted" or "shall not be required" (90.5(B)). Informational notes and informative annexes are informational only and not enforceable (90.5(C), 90.5(D)). - The Code is intended for mandatory application by governmental bodies with legal jurisdiction and for use by insurance inspectors (90.4(A)). - Measurement: metric (SI) is the system of preference (90.9(A)); SI appears first…

Texas Residential Appliance Installer · 15 questions (19% of exam)

Key Concepts

GFCI Protection (210.8) - A listed Class A GFCI shall provide protection for personnel, installed in a readily accessible location (NEC 210.8). Distance from receptacles is measured as the shortest path the power supply cord would follow without piercing a floor, wall, ceiling, or fixed barrier (210.8). - Dwelling units (210.8(A)): all 125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground in bathrooms, garages/accessory buildings at or below grade, outdoors, crawl spaces, basements, kitchens, laundry areas, boathouses, indoor damp/wet locations; within 1.8 m (6 ft) of the top inside edge of a sink bowl; within 6 ft of a bathtub or shower stall; and within 1.8 m (6 ft) of the rim or conductive support framing of open aquatic vessels such as aquariums and bait wells (210.8(A)(14)). - Exception No. 1: receptacles not readily accessible on a circuit dedicated to snow-melting, deicing, or pipeline/vessel heating (426.28 or 427.22). Exception No. 4: factory-installed receptacles not readily accessible mounted internally to bathroom exhaust fan assemblies. - Other than dwelling units (210.8(B)): single-phase circuits **150 V or less to ground, 50 A or…

Key Concepts

Protection of cables and raceways in wood framing - Holes bored through joists, rafters or wood members must have the edge of the hole not less than 32 mm (1¼ in.) from the edge of the member; where that cannot be maintained, protect with a steel plate at least 1.6 mm (1/16 in.) thick — 300.4(A)(1). - Same 32 mm / 1.6 mm rule applies where cables or raceways run parallel to framing members or furring strips — 300.4(D). - Steel plates are not required for rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit or electrical metallic tubing in notches — 300.4(A)(2), Exception No. 1; the bored-hole exception also lists rigid PVC conduit and RTRC — 300.4(A)(1), Exception No. 1. - Under metal-corrugated sheet roof decking, a cable, raceway or box must have not less than 38 mm (1½ in.) from the lowest surface of the decking to the top of the cable, raceway or box — 300.4(E).

Texas Residential Appliance Installer — 15 questions (19% of exam)

Key Concepts

Receptacles, Switches, and Devices

• Reconditioned wiring devices shall not be permitted to be installed. Reconditioned receptacles, attachment plugs, cord connectors, and flanged surface devices are prohibited (NEC 406.2/406.3). This extends to snap switches as wiring devices.
• Push-in (screwless) terminals: Receptacles using screwless terminals of the conductor push-in type construction shall be installed on not greater than 15-ampere branch circuits and connected with 14 AWG solid copper wire only, unless listed and marked for other conductors (NEC 406.3(D)).
• Aluminum conductors: Receptacles rated 20 amperes or less designed for direct connection of aluminum conductors shall be marked CO/ALR (NEC 406.3(C)). Terminals of 15- and 20-ampere receptacles not marked CO/ALR are for copper and copper-clad aluminum only (NEC 406.3(D); see also 406.10).
• Bathtub/shower zone: Receptacles shall not be installed inside a tub or shower or within a zone measured 900 mm (3 ft) horizontally from any outside edge of the bathtub or shower stall (NEC 406.9(C)).
• Noninterchangeability: Devices shall not accept plugs of different voltage or current ratings; however, **20-ampere T-slot receptacles or cord connectors are permitted to accept 15-ampere attachment plugs of the…

Key Concepts

Conductor sizing (Part II, Article 430) - Conductors supplying a single continuous-duty motor must have an ampacity of not less than 125% of the motor full-load current (FLC) as determined by 430.6(A)(1) — NEC 430.22. - Use the table FLC values (Table 430.247–430.250), not the nameplate amperes, for conductor ampacity, switch ratings, and branch-circuit short-circuit/ground-fault (SCGF) device ratings — 430.6(A)(1). Nameplate current is used for separate motor overload protection — 430.6(A)(2). - Wye-start, delta-run: line-side conductors at 125% of FLC; conductors between controller and motor at not less than 72% of FLC (58% × 1.25) — 430.22(C). Part-winding: 62.5% between controller and motor — 430.22(D). - Feeders for several motors: 125% of the highest-rated motor FLC + the sum of the FLC of all other motors, plus 100% of noncontinuous and 125% of continuous non-motor loads — 430.24. The highest-rated motor is determined from the table FLC — 430.17. - Voltage drop: the recommended total from service equipment to motor terminals is 5% (3% for the branch-circuit portion alone) — 430.24 Informational Note.

Residential Appliance Installer

Key Concepts

Service disconnecting means ratings (NEC 230.79) - Installations supplying only limited loads of a single branch circuit: not less than 15 amperes — 230.79(A) - Installations of not more than two 2-wire branch circuits: not less than 30 amperes — 230.79(B) - One-family dwelling: not less than 100 amperes, 3-wire — 230.79(C)

Simultaneous disconnection of ungrounded conductors - Each multiwire branch circuit must have a means that simultaneously disconnects all ungrounded conductors at the point where the branch circuit originates — NEC 210.4(B) - If two or more branch circuits supply devices or equipment on the same yoke or mounting strap, a means to simultaneously disconnect the ungrounded supply conductors must be provided at the point at which the branch circuits originate — NEC 210.7

Accessibility and height (NEC 240.24(A)) Circuit breakers and switches containing fuses shall be readily accessible and installed so the center of the grip of the operating handle, when in its highest position, is not more than 2.0 m (6 ft 7 in.) above the floor or working platform. Overcurrent devices shall not be located in the vicinity of easily ignitible material (240.24(D)), in bathrooms, showering facilities, or locker rooms…

Key Concepts

Listing & general. All electrical equipment covered by Article 680 must be listed (680.2, shown as 680.6 in the 2023 text). Feeders/branch circuits in corrosive or wet locations need an insulated copper EGC, not smaller than 12 AWG (680.7(A)).

Clearances in any direction — Table 680.9(A). Measured from maximum water level: - Insulated cables, 0–750 V to ground, on a solidly grounded bare messenger/neutral: 22.5 ft (6.9 m) to water level; 14.5 ft (4.4 m) to observation stand, tower, or diving platform. - All other conductors 0–15 kV: 17 ft (5.2 m) to observation stand/tower/diving platform. - All other conductors over 15 through 50 kV: 27 ft (8.0 m) to water level. - Horizontal limit extends to the outer edge of those structures but not less than 10 ft (3 m) (Table 680.9(A), Row C). - Communications, radio, and TV coax: not less than 10 ft (3.0 m) above maximum water level (680.9(B)); applies to outdoor spas through 680.42.