Wiring and Protection (Oregon)

Wiring and Protection: Articles 200 to 250 (Oregon Journeyman)

Learning Objectives

1.1 Grounded Conductors: Identification (200.7)

For 6 AWG and smaller, 200.7(A) permits a continuous white outer finish, a continuous gray outer finish, three continuous white or gray stripes on insulation other than green, white or gray insulation with colored tracer threads identifying the source of manufacture, sunlight-resistant outdoor-rated photovoltaic cable permitted by 690.31(C)(1), Type MI cable marked white or gray at terminations, fixture wire identified per 402.8, and aerial cable identified by an exterior ridge. For 4 AWG and larger, 200.7(B) allows only a continuous white or gray finish.

Green, or green with yellow stripes, is never a grounded-conductor color: 250.119 reserves it for equipment grounding conductors, while red and black identify ungrounded conductors under 310.6(A)(3), and in dc systems over 60 volts 215.12(C)(3) assigns red to positive and black to negative polarity.

1.2 Branch-Circuit Loading and Required Circuits (210.11, 210.19, 210.20, 210.23)

Required dwelling circuits, 210.11(C). Two or more 20-ampere small-appliance branch circuits serve the kitchen, pantry, breakfast room, dining room, and similar areas; at least one additional 20-ampere branch circuit serves the laundry area; and at least one 20-ampere branch circuit supplies bathroom receptacle outlets, so a 15-ampere circuit will not do.

Conductors and devices, 210.19(A) and 210.20(A). Ampacity and the device rating shall each be not less than the noncontinuous load plus 125 percent of the continuous load, and the conductor ampacity not less than the load after adjustment and correction factors, unless the assembly is listed for 100 percent operation, where the sum governs. The factor attaches to the continuous load only: 24 amperes continuous requires 1.25 × 24 = 30 amperes, a standard rating under 240.6(A), and 22 amperes continuous gives 1.25 × 22 = _27.5_, so 30 amperes is the smallest standard device satisfying both sections.

Fixed equipment, 210.23. Under 210.23(B)(1) any one cord-and-plug-connected appliance not fastened in place is limited to 80 percent of the circuit rating, so 15 amperes permits 12 amperes and 20 amperes permits 16 amperes; fastened-in-place equipment combined with lighting is limited to 50 percent under 210.23(B)(2). Section 210.23(D) lets a 40- or 50-ampere branch circuit supply cooking appliances fastened in place and, outside dwellings, fixed lighting units with heavy-duty lampholders, while 210.23(E) keeps circuits over 50 amperes to nonlighting loads.

1.3 GFCI Protection for Personnel (210.8)

Section 210.8 requires a listed Class A ground-fault circuit interrupter installed in a readily accessible location. Section 210.8(A) covers all 125-volt through 250-volt receptacles in the listed dwelling-unit locations: bathrooms; garages; outdoors; crawl spaces at or below grade level; basements; kitchens and areas with sinks and food- or beverage-preparation provisions; within 1.8 m (6 ft) of a sink; boathouses; bathtubs and shower stalls; laundry areas; and indoor damp or wet locations. Rooftop receptacles are the one case where accessibility from grade is not required.

Bedrooms, living rooms, dining rooms, and hallways are not in the 210.8(A) list; they raise AFCI questions under 210.12. There is no distance qualification for bathroom or kitchen countertop receptacles, because the 1.8 m (6 ft) measurements apply to sink bowls, bathtubs, and shower stalls, and a dedicated circuit does not remove the requirement: the keys treat an unfinished-basement receptacle installed for a specific appliance as the exception case, while a basement receptacle in general requires GFCI protection.

1.4 AFCI Protection (210.12)

Section 210.12(A) requires arc-fault circuit-interrupter protection for 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices in kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, and laundry areas. It is not limited to bedrooms, does not exclude lighting outlets, and applies at 15 amperes as well as 20 amperes; a 240-volt dryer circuit is outside the voltage range, and a bathroom receptacle circuit is answered by 210.8 instead.

Permitted means include a listed combination-type AFCI at the origin of the circuit, and a listed branch/feeder-type AFCI at the origin combined with a listed outlet branch-circuit-type AFCI at the first outlet box. A standard breaker, a fuse, and a GFCI all fail to provide arc-fault protection, and because AFCI and GFCI are separate requirements a kitchen countertop circuit and a laundry receptacle need both.

1.5 Receptacle Outlets in Dwelling Units (210.52)

Section 210.52 covers 125-volt, 15- and 20-ampere receptacle outlets, counting only outlets not part of a luminaire or appliance, not switch controlled, not in cabinets, and not over 1.7 m (5 1/2 ft) high.

Walls, 210.52(A). No point along the floor line of any wall space may be more than 1.8 m (6 ft) from an outlet; wall space is any space 600 mm (2 ft) or more in width unbroken by doorways, fireplaces, and fixed cabinets or appliances, and foyers count under 210.52(A)(2)(2). Because 210.52(H) requires an outlet in a hallway 3.0 m (10 ft) or more long, the spacing rule places one within 6 ft of each end of a 12 ft hallway.

Rooms, 210.52(B). The rooms listed in 210.52(B)(1) take the wall-space outlets, and 210.52(B)(3) requires not fewer than two small-appliance branch circuits for their countertop receptacles, kept free of other outlets by 210.52(B)(2) except a receptacle installed solely for an electric clock.

Countertops, 210.52(C). Surfaces 300 mm (12 in.) or wider take outlets installed so that no point along the wall line is more than 600 mm (24 in.) horizontally from an outlet, and those outlets do not count as the wall-space outlets of 210.52(A). Exception No. 1 to 210.52(C)(1) removes the requirement directly behind a range, counter-mounted cooking unit, or sink; 210.52(C)(2) triggers islands and peninsulas at a 300 mm (12 in.) short dimension or a 600 mm (24 in.) long dimension; and 210.52(C)(3) permits an outlet in the countertop using a listed receptacle outlet assembly.

Other outlets. Section 210.52(D) requires one per bathroom within 900 mm (3 ft) of the lavatory edge; 210.52(E)(1) one on a balcony or porch accessible from inside the unit; 210.52(F) one for laundry; 210.52(G)(1) one in each basement used for storage; 210.52(G)(2) one in each attached garage and detached garage with power.

1.6 Lighting Load Calculations (120.41 and Table 120.42(A))

The NEC 2026 moved load calculations into Article 120, so the rules older keys cite as Article 220, with the unit load in _220.12_, now appear as 120.41 for dwellings and 120.42 for other occupancies. Section 120.41 sets the minimum unit load for one-family, two-family, and multifamily dwellings at not less than 22 volt-amperes/m², which is 2 volt-amperes/ft², covering lighting and receptacle outlets, so a 4,000 ft² dwelling carries 8,000 VA before demand factors.

Section 120.42(A) requires a unit load not less than that specified in Table 120.42(A) for the occupancy, times the floor area under 120.5(C). Representative values: office, fire station, and police station 1.3 volt-amperes/ft²; automotive facility, dormitory, restaurant, and school/university 1.5 volt-amperes/ft²; retail 1.9 volt-amperes/ft²; penitentiary and transportation 1.2 volt-amperes/ft²; gymnasium 1.7 volt-amperes/ft². An 8,000 ft² office at 1.3 volt-amperes/ft² gives 10,400 VA, while 1.4 or 1.5 volt-amperes/ft² yields 11,200 VA.

1.7 Feeder Conductor Ampacity (215.1, 215.4, 215.6)

Section 215.1 fixes the scope: Article 215 covers installation, overcurrent protection, minimum size, and ampacity of conductors for feeders not over 1000 volts ac or 1500 volts dc, while feeders over 1000 volts ac fall under Article 266.

Under 215.4(A)(1) the minimum feeder conductor ampacity shall be not less than the noncontinuous load plus 125 percent of the continuous load. Exception No. 1 permits the sum of the loads where the assembly, including the feeder overcurrent devices, is listed for 100 percent operation, and Exception No. 2 permits the same sum where the feeder is connected at both its supply and load ends to separately installed pressure connections covered in 110.14(C)(2) and no portion extends into an enclosure containing the feeder terminations. Section 215.4(A)(2) requires the same noncontinuous load plus 125 percent of the continuous load after adjustment or correction factors are applied.

Worked minimums: 40 amperes continuous plus 30 noncontinuous gives 30 + (1.25 × 40) = 80 amperes, while 80 plus 30 at a listed 100 percent assembly gives 110 amperes, 70 plus 50 gives 120 amperes, 50 plus 40 gives 90 amperes, and 60 plus 40 with pressure connections gives 100 amperes.

Section 215.6 requires a feeder supplying branch circuits that need equipment grounding conductors to include or provide one to which the branch-circuit conductors connect, and a grounded conductor is not a substitute for it.

1.8 Feeder Overcurrent Protection (215.5)

Section 215.5 requires the feeder overcurrent protective device rating to be not less than the noncontinuous load plus 125 percent of the continuous load, with an exception allowing the sum of the loads where the assembly, including the feeder overcurrent devices, is listed for 100 percent operation.

Distractor arithmetic is predictable: applying the factor to the entire load gives 70 × 1.25 = _87.5_ or 90 × 1.25 = _112.5_, applying it to the continuous load alone gives _62.5_, and stacking it on an already-increased continuous load gives 30 + (1.25 × 50) = _92.5_ or 125 percent of a 30-ampere load, _37.5_; none of these values appears in the code.

1.9 Feeder and Service Ground-Fault Protection (215.9, 215.10, 230.95)

Read 215.9 and 215.10 apart, because the titles look alike. Section 215.9 permits a feeder to be protected by a listed ground-fault circuit interrupter for personnel in a readily accessible location in lieu of the interrupters specified in 210.8, while 215.10 carries ground-fault protection of equipment; keys quoting the dc rule as 215.9(B) describe what the 2026 text places in 215.10(B).

Under 215.10(A), each feeder disconnect rated 1000 amperes or more on solidly grounded wye systems of more than 150 volts to ground but not exceeding 1000 volts phase-to-phase shall be provided with ground-fault protection of equipment in accordance with 230.95. Under 215.10(B) the same 1000-ampere threshold applies on solidly grounded dc systems of more than 150 volts to ground but not exceeding 1500 volts dc line-to-line. Exception No. 1 removes both where the disconnecting means serves a continuous industrial process in which a nonorderly shutdown will introduce additional or increased hazards.

1.10 Feeder and Branch-Circuit Conductor Identification (215.12)

Section 215.12(A) sends the insulated grounded conductor of a feeder to 200.7 for identification, and 215.12(C)(2) addresses premises wiring supplied from more than one nominal voltage system: each ungrounded feeder conductor shall be identified by phase or line and by nominal voltage system at all termination, connection, and splice points. Identification by phase alone or by voltage alone is incomplete, and the requirement is not waived because the systems run in separate raceways.

Section 215.12(C)(3) covers dc systems over 60 volts: conductors 6 AWG or smaller carry a continuous red outer finish for positive polarity and a continuous black outer finish for negative polarity, while conductors 4 AWG or larger are identified by polarity at all termination, connection, and splice points by marking tape or tagging. White identifies grounded conductors under 200.7 and green equipment grounding conductors under 250.119.

1.11 Outside Branch Circuits and Feeders (225.31, 225.33, 225.35, 225.36, 225.37)

Disconnecting means and location, 225.31. Means shall be provided to disconnect all ungrounded conductors supplying or passing through the building or structure, and 225.31(B) permits that means either inside or outside the building served, or where the conductors pass through it. Inside, it must be readily accessible nearest the point of entrance of the conductors; outside, on or within sight of the building per 110.29. Older keys cite this rule as _225.32(B)_, while the 2026 text carries it in 225.31(B); the 3.0 m (10 ft) measurement in distractors belongs to services, where 230.70(A)(1) applies.

Disconnect count and access, 225.33(A) and 225.35. The disconnecting means for each supply may consist of not more than six switches or six circuit breakers mounted in a single enclosure, in a group of separate enclosures, or in or on a switchboard or switchgear. Each occupant of a multiple-occupancy building shall have access to the occupant's supply disconnecting means, and only where building management provides electric supply and electrical maintenance under continuous supervision may a disconnecting means supplying more than one occupancy be accessible to management alone.

Type and identification, 225.36 and 225.37. The disconnecting means shall be a circuit breaker, molded case switch, general-use switch, snap switch, or other approved means; cord-and-plug connections, pull-out fuse blocks, and terminal lug assemblies do not qualify. A building with any combination of feeders, branch circuits, or services passing through or supplying it requires a permanent plaque or directory at each disconnect location denoting the other circuits and the areas served.

1.12 Overcurrent Protective Devices: Rating and Location (240.4, 240.6, 240.21, 240.24)

Section 240.4 requires conductors to be protected against overcurrent in accordance with their ampacities, so the device rating may not exceed the conductor ampacity except where a permitted exception applies. Section 240.6(A) lists the standard ampere ratings: 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 400, 500, 600, and 1000 to 1200 amperes. Because 65 and 75 are not standard ratings, a load of 68 amperes on conductors with a 75-ampere ampacity takes 70 amperes, and a 60-ampere circuit with 6 AWG copper at 65 amperes of ampacity takes 60 amperes.

Section 240.21 places overcurrent protection where conductors receive their supply, subject to its tap rules, and 240.24 requires readily accessible devices and prohibits bathrooms of dwelling units and clothes closets., and 110.14(C)(2) pressure connections trigger Exception No. 2 to 215.4(A)(1).

1.13 Equipment Grounding Conductors (250.4, 250.110, 250.119, 250.122, 250.146)

The equipment grounding conductor provides a low-impedance path for fault current so that overcurrent protective devices operate, and 250.4(A)(5) requires it to be capable of safely carrying the maximum ground-fault current likely to be imposed on it. It does not carry current in normal operation, is not the grounded conductor, and is not a voltage-drop remedy; 250.4(B)(4) requires continuity without relying on a metal enclosure. Section 250.110 requires exposed metal parts of fixed equipment likely to become energized to be connected to an equipment grounding conductor, and 250.119 assigns green, or green with yellow stripes, to that conductor.

Table 250.122 sizes the equipment grounding conductor by the rating of the overcurrent device ahead of the equipment: 60 amperes requires 10 AWG copper, 100 amperes 8 AWG, 200 amperes 6 AWG, 300 amperes 4 AWG, 400 amperes 1/0 AWG, and 600 amperes 2/0 AWG. Section 250.146(D) permits an insulated equipment grounding conductor run to an isolated receptacle, a design choice rather than feeder protection.

1.14 Grounding Electrode System and Conductors (250.50, 250.52, 250.53, 250.64, 250.66)

Section 250.50 requires all grounding electrodes described in 250.52(A)(1) through 250.52(A)(8) that are present at each building to be bonded together to form the grounding electrode system. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more is one of them under 250.52(A)(1), and 250.53(D)(2) requires a metal water pipe used as an electrode to be supplemented by an additional electrode. Section 250.52(A)(3) requires a concrete-encased electrode to have at least 6 m (20 ft) of bare copper conductor not smaller than 4 AWG.

Table 250.66 sizes the grounding electrode conductor on the largest ungrounded service-entrance conductor: copper service-entrance conductors of 2 AWG through 3/0 AWG require a 4 AWG copper conductor, the over 350 kcmil through 600 kcmil column requires 2/0 AWG, and the over 600 kcmil through 1100 kcmil column requires 3/0 AWG, placing an 800-ampere service with parallel 500 kcmil copper conductors per phase in the 3/0 AWG column. Two caps change the answer: 250.66(A) permits a conductor connected only to a rod, pipe, or plate electrode to be no larger than 6 AWG copper, so a 3/0 AWG service run to a ground rod takes 6 AWG copper, and 250.66(B) applies a comparable cap of 4 AWG copper to a concrete-encased electrode. Section 250.64(E) requires that a grounding electrode conductor installed in metal raceway be electrically bonded to that raceway at both ends.

1.15 Bonding Metal Water Piping (250.104)

Where metal water piping is present, 250.104 requires it to be bonded to the equipment grounding conductor or to the grounded conductor of the separately derived system supplying the building, with the jumper sized for the circuit likely to energize the piping; bonding the grounded conductor at every outlet is not required and would create parallel return paths. The transformer enclosure of a separately derived system is bonded whether indoors or outdoors, and a concrete-encased electrode is a grounding electrode question rather than a bonding requirement.

Code Navigation

Common Exam Traps

Practical Field Points

Summary

Articles 200 through 250 carry the wiring and protection rules an Oregon journeyman must navigate fastest. Article 200 settles conductor identity: 200.7(A) lists the permitted identifications for grounded conductors of 6 AWG and smaller, 200.7(B) limits 4 AWG and larger to a white or gray finish, and green belongs to the equipment grounding conductor under 250.119.

Article 210 governs branch circuits: 210.11(C) requires the small-appliance, laundry, and bathroom 20-ampere circuits; 210.19(A) and 210.20(A) apply the noncontinuous load plus 125 percent of the continuous load, so 22 amperes continuous gives _27.5_ and 24 amperes gives 30 amperes; and 210.23 caps cord-and-plug equipment at 80 percent and fastened-in-place equipment with lighting at 50 percent. Section 210.8 requires Class A GFCI protection in a readily accessible location while 210.12 requires AFCI protection on 120-volt, 15- and 20-ampere circuits, so kitchen and laundry circuits carry both, and 210.52 fixes the outlet counts and geometry, including the 1.8 m (6 ft) floor-line rule, the 300 mm (12 in.) countertop trigger, the 900 mm (3 ft) lavatory rule, and two small-appliance circuits. Article 120 holds the arithmetic: 120.41 sets dwellings at 2 volt-amperes/ft² and Table 120.42(A) sets non-dwelling unit loads, with 1.3 volt-amperes/ft² for offices turning an 8,000 ft² floor into 10,400 VA.

Article 215 applies the same factors to feeders through 215.4(A)(1), 215.4(A)(2), 215.5, and 215.6, and 215.10 requires ground-fault protection of equipment for feeder disconnects rated 1000 amperes or more on solidly grounded wye and dc systems per 230.95, unless the continuous industrial process exception applies. Article 225 governs outside feeders through 225.31(B), 225.33(A), 225.35, 225.36, and 225.37; Article 240 requires protection where conductors receive supply under 240.21, readily accessible devices under 240.24, and ratings from 240.6(A) under 240.4; and Article 250 closes the circuit with 250.4(A)(5), 250.110, Table 250.122, 250.50, 250.52(A)(1) with 250.53(D)(2), Table 250.66, 250.64(E), and 250.104.