NEC 200-225, 242 — Wiring & Protection (Washington)

NEC 200-225, 280-285 — Wiring & Protection (Washington Journeyman)

Learning Objectives

1.1 Grounded Conductors: Use and Identification (Article 200)

An insulated grounded conductor needs insulation rated, other than color, for any ungrounded conductor of the same circuit at 1000 volts or less (200.4), and grounded conductors must connect to the supply system grounded conductor so that a common grounded system is maintained (200.5). Section 200.6 governs use rather than color: a neutral shall not serve more than one branch circuit, more than one multiwire branch circuit, or more than one set of ungrounded feeder conductors unless permitted elsewhere. White, gray, or white- or gray-striped insulation is restricted to grounded conductors unless 200.8(C) permits reidentification, and green is never permitted (200.8).

200.7(A) applies to 6 AWG and smaller, 200.7(B) to 4 AWG and larger:

The tracer threads of 200.7(A)(4) carry no required color: they identify the source of manufacture. A 4 AWG grounded conductor takes a continuous white or gray outer finish per 200.7(B)(1) or 200.7(B)(2), never stripes or tracers.

1.2 GFCI Protection (210.8)

Section 210.8 requires ground-fault circuit-interrupter protection for personnel on receptacles in the locations listed. For dwellings, 210.8(A) covers 125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground in bathrooms; garages; accessory buildings; outdoors; crawl spaces at or below grade level; basements; kitchens; areas with sinks and food- or beverage-preparation provisions; within 1.8 m (6 ft) of the top inside edge of a sink bowl; boathouses; bathtubs or shower stalls within 1.8 m (6 ft) of the outside edge; laundry areas; and indoor damp or wet locations.

Countertop receptacles in a dwelling-unit kitchen require GFCI protection: the trigger is the countertop surface, not a measured distance from the sink. The 1.8 m (6 ft) measurement used for sink bowls, bathtubs, and shower stalls is the shortest path the power supply cord would follow without piercing a floor, wall, ceiling, or fixed barrier. Bedrooms, hallways, and living rooms are not GFCI locations, so a receptacle question about them is an AFCI question under 210.12. Section 210.8(B) covers non-dwelling locations including rooftops, service bays, and locker rooms, and 210.8(C) through 210.8(F) add crawl-space lighting, specific appliances, and dwelling outdoor outlets.

1.3 AFCI Protection (210.12)

Section 210.12 applies to 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices in dwelling-unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, and similar areas. It is not limited to bedrooms, does not exclude lighting outlets, and applies at 15 amperes as well as 20 amperes. The permitted means in 210.12(A) include a listed combination-type AFCI at the origin of the branch circuit to protect the entire circuit, and a listed branch/feeder-type AFCI at the origin with a listed outlet branch-circuit-type AFCI at the first outlet box. A standard breaker with a GFCI receptacle, or a GFCI breaker, provides no arc-fault protection at all.

1.4 Branch Circuits Required in Dwelling Units (210.11, 210.23)

210.11(C)(1), small appliances. Two or more 20-ampere small-appliance branch circuits shall serve the receptacle outlets specified by 210.52(B) (kitchen, pantry, breakfast room, dining room, and similar areas) with no other outlets, and none may serve more than one kitchen.

210.11(C)(2), laundry. At least one additional 120-volt, nominal, 20-ampere branch circuit shall supply the laundry area receptacle outlet(s) with no other outlets, and it may not be combined with a small-appliance circuit.

210.11(C)(3), bathrooms. One or more 120-volt, nominal, 20-ampere branch circuits shall supply bathroom receptacle outlets and any countertop and similar work surface outlets with no other outlets, so a 15-ampere circuit or a share with the laundry circuit is not permitted. Where the circuit supplies a single bathroom, other equipment outlets in that same bathroom are permitted per 210.23(B)(1) and 210.23(B)(2), but never a second bathroom, the kitchen, or the garage.

210.11(C)(4), garages. At least one 120-volt, nominal, 20-ampere branch circuit shall supply the required garage receptacle outlets, with an outlet in each vehicle bay not more than 1.7 m (5 1/2 ft) above the floor.

Section 210.23(B) limits a 20-ampere circuit to 80 percent of its rating for cord- and plug-connected equipment, and to 50 percent for fastened-in-place equipment where lighting is also supplied.

1.5 Branch-Circuit Conductor Sizing and Voltage Drop (210.19)

Section 210.18 sets the standard ratings at 10, 15, 20, 30, 40, and 50 amperes and forbids a 10-ampere circuit to supply receptacle outlets. Branch-circuit conductors must have an ampacity not less than the larger of the noncontinuous load plus 125 percent of the continuous load (210.19(A)(1)) or the maximum load to be served after applying adjustment and correction factors (210.19(A)(2)). Where the assembly, including the branch-circuit overcurrent protective devices, is listed for operation at 100 percent of its rating, the ampacity may be the sum of the loads instead.

Voltage drop. The Informational Note to 210.19 recommends a voltage drop not exceeding 3 percent at the farthest outlet, with a maximum total on both feeders and branch circuits not exceeding 5 percent; see 215.4(A)(2) Informational Note No. 2 for the feeder portion.

1.6 Receptacle Outlets in Dwelling Units (210.52)

Section 210.52 governs 125-volt, 15- and 20-ampere receptacle outlets, counting only outlets not part of a luminaire or appliance, not switch-controlled, not inside cabinets, and not more than 1.7 m (5 1/2 ft) above the floor.

Wall spaces, 210.52(A)(1) and (A)(2). No point measured horizontally along the floor line of any wall space may be more than 1.8 m (6 ft) from a receptacle outlet. A wall space is any space 600 mm (2 ft) or more in width, unbroken along the floor line by doorways, fireplaces, fixed appliances, and fixed cabinets; a wall space 1.8 m (6 ft) wide is satisfied by one outlet.

Countertops and islands, 210.52(C). Outlets for countertop and work surfaces 300 mm (12 in.) or wider shall be installed so that no point along the wall line is more than 600 mm (24 in.) horizontally from an outlet, so a 3.0 m (10 ft) countertop needs at least two, and countertop outlets do not count as the wall-space outlets required by 210.52(A). Under 210.52(C)(2) islands and peninsulas are conditional: an outlet, if provided, must follow 210.52(C)(3) and 210.52(C)(4), and if none is provided, provisions must be installed for future addition of one.

Bathrooms, garages, hallways. At least one outlet shall be installed in a bathroom within 900 mm (3 ft) of the outside edge of each sink (210.52(D)); each garage requires an outlet in each vehicle bay, not more than 1.7 m (5 1/2 ft) above the floor (210.52(G)(1)); and a hallway 3.0 m (10 ft) or more in length requires at least one outlet (210.52(H)).

1.7 Feeder Conductor Size and Feeder Overcurrent Protection (215.4, 215.5)

215.4(A)(1), conductors. The minimum feeder conductor ampacity is the noncontinuous load plus 125 percent of the continuous load. For 80 amperes continuous and 20 amperes noncontinuous at an assembly not listed for 100 percent operation, 20 + (1.25 × 80) = 120 amperes; 100 omits the factor and 125 applies it to the 100-ampere total. Where the assembly is listed for operation at 100 percent of its rating, the ampacity may be the sum of the loads. Keys that predate the 2026 edition cite this rule as _215.2_; the current text carries it in 215.4(A)(1).

215.5, overcurrent protection. The device rating shall not be less than the noncontinuous load plus 125 percent of the continuous load, so 40 amperes continuous plus 30 amperes noncontinuous requires 30 + (1.25 × 40) = 80 amperes; where the assembly is listed for operation at 100 percent of its rating, the device rating may be the sum of the loads. Working backward, a feeder with an ampacity of 200 amperes supplying 150 amperes of continuous load passes, because 125 percent of 150 amperes is _187.5_.

Neighboring rules used as distractors. Service-entrance conductors are governed by 230.42, an ampacity not less than the maximum calculated load to be served, and the load calculations sit in Article 120 of the NEC 2026, which older keys cite as Article 220 with the lighting-load rule at _220.12_. Article 120 calculates, 215.4 and 215.5 size the feeder and its device, and 230.42 sizes the service, while 215.6 requires a feeder supplying branch circuits that need equipment grounding conductors to include or provide one.

1.8 Outside Branch Circuits and Feeders (225.14, 225.17, 225.18, 225.19)

Spacings and supports. Open conductors shall be separated from open conductors of other circuits or systems by not less than 100 mm (4 in.) (225.14(A)). Conductors on poles not placed on racks or brackets require a separation of not less than 300 mm (1 ft) and a horizontal climbing space of 750 mm (30 in.) for power conductors below communications conductors; where power conductors are alone or above communications conductors, the climbing space is 600 mm (24 in.) at 300 volts or less and 750 mm (30 in.) above 300 volts. Under 225.17 only the conductors specified within the section may be attached to the mast, which must be installed per 225.17(A) and 225.17(B) with adequate strength, or braced or guyed, to withstand the strain.

Clearances from buildings (225.19). The vertical clearance above a roof is not less than 2.6 m (8 ft 6 in.), maintained for a distance not less than 900 mm (3 ft) in all directions from the edge of the roof. Clearances from signs, chimneys, antennas, tanks, and other nonbuilding structures shall not be less than 900 mm (3 ft) (225.19(B)), and horizontal clearances from open-conductor spans to buildings shall not be less than 900 mm (3 ft) (225.19(C)).

1.9 Surge Arresters and Surge Protective Devices (Article 242)

Article 242 of the NEC 2026, Overvoltage Protection, consolidates what older editions split between Article 280 (surge arresters over 1000 volts) and Article 285 (SPDs at 1000 volts or less). Keys still cite the old numbers, so learn both: _280.24_ (location) is now 242.46, _280.25_ (grounding conductor) is 242.48 and 242.52, _285.3_ (listing) is 242.2, _285.4_ (location) is 242.22, _285.5_ (connection) is 242.30, and _285.12_ (conductor size) is 242.28.

Surge arresters. An arrester shall not be installed where its rating is less than the maximum continuous phase-to-ground voltage at the power frequency available at the point of application (242.40), and its duty cycle rating shall be not less than 125 percent of the maximum continuous operating voltage there (242.42). Exam keys state the older _280.24_ rule as location as close as practicable to the equipment protected, with connecting conductors not exceeding 1.8 m (6 ft), and the 242.48 routing rule as no longer than necessary and without unnecessary bends, with conductors not smaller than 6 AWG copper or aluminum (242.52). The grounding conductor must be as short as practicable and without sharp bends, which is what the older _280.25_ material expects: no maximum length applies, so options offering 3 m (10 ft) or 4.5 m (15 ft) as a maximum state values the code does not contain.

Surge protective devices. SPDs rated not over 1000 volts ac or 1500 volts dc shall be listed (242.2), and each SPD used at a point on a circuit shall be connected to each ungrounded conductor (242.20). It is permitted on the line or load side of the service disconnect and on the load side of a feeder disconnect (242.22). Conductors connecting the SPD to the line or bus and to ground shall be no longer than necessary and shall avoid unnecessary bends (242.24), and SPD conductors shall not be smaller than 14 AWG copper or 12 AWG aluminum (242.28) — a question keyed to the former _285.12_ expects 12 AWG copper or 10 AWG aluminum for connecting an SPD to a busbar.

Rating, marking, disconnect. An SPD shall not be installed where its rating is less than the maximum continuous phase-to-ground voltage available at the point of application (242.12) — the voltage-rating rule older material cites as _285.6_. It shall be marked with a short-circuit current rating (242.8) and indicate proper functioning (242.9). The marking list older keys associate with _285.7_ names the maximum continuous operating voltage, the nominal discharge current, and the voltage protection rating; both 215.18(E) and 230.67(E) require a nominal discharge current rating of not less than 10kA. No general requirement obliges an SPD to have a disconnecting means, which decides "which of the following is not a requirement" questions; a disconnect used only for surge-protective device(s) is not counted among the permitted service disconnects (230.71(A)(2)), and SPDs are required at services supplying dwelling units (230.67(A)).

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Summary

Article 200 fixes the identity of the grounded conductor: 200.4 covers insulation, 200.5 the connection to the grounded supply, 200.6 limits how a neutral may be used, 200.8 restricts white or gray to grounded conductors, and 200.7 splits identification by size — 200.7(A) for 6 AWG and smaller (white, gray, stripes on other than green insulation, tracer threads identifying the source of manufacture, photovoltaic cable permitted by 690.31(C)(1), Type MI terminations, an exterior ridge on aerial cable) and 200.7(B) for 4 AWG and larger, which takes a continuous white or gray outer finish. Article 210 supplies the circuit rules: 210.11(C) requires small-appliance, laundry, bathroom, and garage circuits; 210.8 requires GFCI protection in the listed locations while 210.12 requires AFCI protection on 120-volt, 15- and 20-ampere dwelling-unit circuits; 210.19 sizes conductors by the larger of the noncontinuous load plus 125 percent of the continuous load or the adjusted and corrected load, with the 100 percent rated assembly exception; and 210.52 fixes how many receptacle outlets walls, countertops, bathrooms, garages, and hallways need.

Article 215 applies the same arithmetic to feeders, with 215.4(A)(1) for conductors, 215.5 for the device, and 215.6 for the feeder equipment grounding conductor, and Article 225 takes the wiring outside: 225.14 sets 100 mm (4 in.) between circuits and 300 mm (1 ft) between conductors on poles with 600 mm (24 in.) or 750 mm (30 in.) of climbing space, 225.17 governs masts, and 225.18 and 225.19 set the 3.0 m (10 ft), 3.7 m (12 ft), 4.5 m (15 ft), 5.5 m (18 ft), and 7.5 m (24 1/2 ft) clearances above ground and the 2.6 m (8 ft 6 in.) roof clearance with its 900 mm (3 ft) requirement. Articles 280 and 285 have become Article 242: Part III governs surge arresters over 1000 volts, where the duty cycle rating is not less than 125 percent of the maximum continuous operating voltage, and Part II governs SPDs at 1000 volts or less, where listing, location, routing, conductor size, and connection carry the rules the older section numbers still describe.