OK Electrician cheat sheet

Article 100: "Listed" means equipment included in a list published by an organization acceptable to the AHJ that maintains periodic inspection of production and whose listing states the equipment meets a recognized standard or has been tested and found suitable.

Table 110.26(A)(1) working-space depth, 0-150 V to ground: 3 ft for Conditions 1, 2 and 3; for 151-600 V to ground: 3 ft (Condition 1), 3.5 ft (Condition 2), 4 ft (Condition 3).

110.26(A)(2) width of working space: not less than 30 in., or the width of the equipment, whichever is greater; 110.26(A)(3) height: 6.5 ft from grade, floor or platform.

110.26(E) dedicated equipment space: 30 in. deep from the front face, the width of the equipment, and 6 ft above the equipment or to the structural ceiling, whichever is lower.

110.26(C)(2): equipment rated 1200 A or more and over 6 ft wide requires one entrance at each end of the working space.

110.24(A): service equipment in other than dwelling units must be field-marked with the maximum available fault current and the date the calculation was performed.

110.14(D): conductor terminations must be tightened to the torque value marked on the equipment or given in the manufacturer's instructions.

110.3(B): listed or labeled equipment must be installed and used in accordance with any instructions included in the listing or labeling.

110.12: electrical equipment must be installed in a neat and workmanlike manner; unused openings in enclosures must be effectively closed.

300.4(A)(1): bored holes in wood members must be at least 1 1/4 in. from the nearest edge, or the cable must be protected by a steel nail plate at least 1/16 in. thick.

Table 300.5 minimum cover for direct-buried cables: 24 in. general; 18 in. for 120 V, 20 A residential circuits; 12 in. for 120 V, 20 A residential circuits with GFCI protection.

334.30: nonmetallic-sheathed cable secured within 12 in. of each box and at intervals not exceeding 4.5 ft.

Table 352.30: Schedule 40 PVC conduit supported at 3 ft intervals for 1/2 in. through 1 in., and 5 ft for 1 1/4 in. through 2 in.

358.30: EMT secured within 3 ft of each box and at intervals not exceeding 10 ft.

Table 314.16(B) box fill allowance per conductor: 18 and 16 AWG = 1.75 cu. in.; 14 AWG = 2.0; 12 AWG = 2.25; 10 AWG = 2.5.

314.28(A): straight-pull box dimension at least 8 times the trade size of the largest raceway; angle pulls at least 6 times the largest raceway plus the other raceways in the same row.

310.15(B)(3)(a) adjustment for more than three current-carrying conductors in a raceway: 4-6 = 80%, 7-9 = 70%, 10-20 = 50%.

300.22: only Types MC, AC, MI, or flexible metal conduit may be installed in ducts or plenums used for environmental air.

240.4(D) small-conductor overcurrent limits: 18 AWG = 7 A, 16 AWG = 10 A, 14 AWG = 15 A, 12 AWG = 20 A, 10 AWG = 30 A.

240.6(A) standard ampere ratings include 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, 400, 500, 600, 800, 1000, 1200 A.

240.21(B)(1) 10-ft tap rule: tap conductor ampacity at least one-tenth the rating of the overcurrent device ahead of it, no splices, terminated in a single circuit breaker or fuse.

250.52(A) grounding electrodes: metal water pipe with at least 10 ft in direct earth contact; rod or pipe at least 8 ft long; ground ring of at least 20 ft of bare 2 AWG copper; concrete-encased electrode of 20 ft of 1/2 in. rebar or 4 AWG copper.

250.53: rod, pipe and plate electrodes must be at least 6 ft apart; a single rod must be supplemented by an additional electrode unless it has a resistance of 25 ohms or less.

250.66: the grounding electrode conductor to a rod, pipe or plate electrode is not required to be larger than 6 AWG copper; for service conductors over 1100 kcmil copper the maximum required is 3/0 copper.

Table 250.122 copper equipment grounding conductors: 20 A circuit = 12 AWG, 100 A = 8 AWG, 200 A = 6 AWG, 400 A = 3 AWG.

250.122(B): where ungrounded conductors are increased in size, the equipment grounding conductor must be increased proportionally.

250.24(A)(1): the grounded service conductor is connected to the grounding electrode conductor at the service; 250.24(A)(5) prohibits regrounding it on the load side of the service disconnect.

210.52(A)(1): in dwelling units, receptacle outlets along walls must be installed so no point on the wall line is more than 6 ft from a receptacle, which limits spacing to 12 ft maximum.

210.52(C)(1): dwelling kitchen countertops require at least one receptacle, with no point along the counter wall line more than 24 in. from a receptacle.

210.8(A): GFCI protection is required for 125 V, 15 and 20 A receptacles in dwelling bathrooms, garages, outdoors, kitchens, laundry areas, unfinished basements, crawl spaces, and within 6 ft of sinks.

210.12(A): arc-fault circuit-interrupter protection is required for 120 V, 15 and 20 A branch circuits supplying dwelling unit living areas, bedrooms, halls, closets and similar rooms.

210.11(C): at least two 20 A small-appliance branch circuits, one 20 A laundry branch circuit, and one 20 A bathroom branch circuit are required in dwelling units.

230.79(C): the service disconnecting means for a one-family dwelling must have a rating of not less than 100 A, three-wire.

230.24(B) overhead service conductor clearances: 10 ft above sidewalks and grade, 12 ft above residential driveways, 18 ft above public roads and other areas subject to truck traffic.

210.63: a 125 V receptacle outlet must be provided within 25 ft of heating, air-conditioning and refrigeration equipment for servicing.

210.19(A) Informational Note: branch-circuit voltage drop should not exceed 3 percent, with a total of 5 percent for feeder plus branch circuit.

400.8: flexible cord may not be used as a substitute for fixed wiring, run through holes in walls or ceilings, concealed behind building surfaces, or installed above suspended ceilings.

404.8(A): switches and circuit breakers used as switches must be located not more than 6 ft 7 in. above the floor or working platform.

406.12: tamper-resistant receptacles are required in dwelling units; 406.9 requires weather-resistant receptacles in wet and damp locations.

410.16: luminaires in clothes closets must maintain at least 12 in. clearance from the nearest point of the storage shelf.

422.13: the branch circuit for a storage-type water heater rated 20 gallons or more must be rated at least 125 percent of the appliance's nameplate rating.

424.3(B): branch-circuit conductors and overcurrent devices for fixed electric space-heating equipment must be sized at 125 percent of the nameplate rating.

440.14: the disconnecting means for air-conditioning and refrigerating equipment must be within sight of and not more than 50 ft from the equipment.

Table 450.3(B): for transformers rated 1000 V or less, the primary overcurrent device is set at 125 percent of primary current when the secondary is protected at 125 percent, and may be increased up to 300 percent for primary-only protection.

Article 500: Class I = flammable gases or vapors; Class II = combustible dust; Class III = ignitable fibers or flyings; each class is divided into Division 1 (normal) and Division 2 (abnormal) conditions.

511.3: in commercial garages, the area up to 18 in. above the floor is a Class I, Division 2 location, along with areas near fuel-dispensing or repair points.

517.13: health care facility patient care areas require a redundant ground path, typically an insulated copper equipment grounding conductor installed in metallic raceways.

680.22(A)(1): receptacles supplying a permanently installed swimming pool must be not less than 6 ft from the pool edge, and all receptacles between 6 ft and 20 ft require GFCI protection.

680.26(B): equipotential bonding is required for conductive pool shells and for perimeter surfaces extending at least 3 ft horizontally from the inside wall of the pool.

690.8(A): photovoltaic source-circuit current is calculated as 125 percent of the short-circuit current, and conductor ampacity must be at least 125 percent of that value.

690.12: rapid shutdown must reduce conductors outside the array boundary to 30 V or less within 30 seconds after shutdown is initiated.

Article 700 covers emergency systems, Article 701 legally required standby systems, and Article 702 optional standby systems, each with different capacity and testing requirements.

590.6: all 125 V, 15 and 20 A receptacle outlets used during construction must have ground-fault circuit-interrupter protection.

430.6(A)(1): motor full-load current for sizing conductors, feeders and protection is taken from Tables 430.247 through 430.250, not from the motor nameplate.

430.22: branch-circuit conductors supplying a single motor must have an ampacity of at least 125 percent of the motor full-load current rating.

Table 430.52: branch-circuit short-circuit protection may be 175 percent of motor FLC for an inverse-time breaker, 175 percent for a dual-element fuse, and 300 percent for a non-time-delay fuse.

430.32: overload protection is set at 125 percent of nameplate current for motors with a 1.15 service factor or 40 degrees C rise, and 115 percent for all other motors.

430.24: feeder conductors supplying several motors must have an ampacity of at least 125 percent of the largest motor FLC plus 100 percent of all other motor loads.

430.102(B): a motor disconnecting means must be located within sight of the motor and of the driven machinery.

440.22(A): short-circuit protection for an air-conditioning compressor may not exceed 175 percent of rated-load current, increased to 225 percent if the unit will not start.

440.32: branch-circuit conductors supplying a single hermetic refrigerant motor-compressor must have an ampacity of at least 125 percent of the rated-load current.

Article 725 divides remote-control and signal circuits into Class 1, Class 2 and Class 3; Class 2 and 3 circuits are limited-energy circuits governed by the power limits in Tables 725.121.

725.136: Class 2 and Class 3 conductors must be separated from Class 1 and power conductors by at least 1/4 in., a barrier, or a listed raceway or cable assembly.

Article 760 distinguishes power-limited fire alarm (PLFA) circuits from non-power-limited fire alarm (NPLFA) circuits, which follow Article 300 wiring methods.

800.133(A)(1): communications cables must be separated by at least 2 in. from power conductors, Class 1 circuits, and NPLFA conductors unless a permanent barrier separates them.

250.94: an intersystem bonding termination must be provided at the service to bond communications, antenna, and other system grounding conductors.

800.100: communications circuits entering a building must have a listed primary protector installed as near as practicable to the point of entry.

Article 770 covers optical fiber cables and requires separation from power conductors similar to communications cable rules.

Article 810: outdoor radio and television antennas must be bonded to the building grounding electrode system, and masts must maintain the required clearances from power conductors.

Electrical licensing in Oklahoma is administered by the Construction Industries Board under the Oklahoma Electrical Licensing Act, Title 59 of the Oklahoma Statutes, Sections 1680 through 1697.

Rules implementing the Act are published in the Oklahoma Administrative Code under Title 158, the Construction Industries Board rules.

Electrical contracting requires a licensed electrical contractor; electrical work must be performed by licensed journeymen or by registered apprentices under supervision.

Apprentices must be registered with the Board and may perform electrical work only while under the supervision of a licensed journeyman or contractor.

Journeyman and contractor applicants must pass the Board-approved licensing examination and meet the required experience or training qualifications.

Licenses are renewed on a recurring cycle established by Board rule, subject to continuing education and fee requirements.

Local authorities having jurisdiction issue permits and perform inspections; the state code adopted by Board rule applies where local amendments do not govern.

Unlicensed electrical work may result in Board discipline, administrative penalties, and misdemeanor prosecution under the Oklahoma Electrical Licensing Act.