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6.3 GFCI Protection — Article 210.8

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Alaska Journeyman Electrician Study Guide Exam

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1 Chapter 1: Alaska Certificates of Fitness, Law & Exam Logistics

1.1 The Alaska Certificate of Fitness System 1.2 Journeyman Eligibility: 8,000 Hours and How Alaska Counts Them 1.3 Trainee, Residential Wireman, Lineman, Provisional & Reciprocal Certificates 1.4 The Journeyman Examination: Format, Scheduling, Open-Book Rules & Retakes 1.5 Adopted Codes, Fees, Renewal, Inspection & Enforcement

2 Chapter 2: Using the 2020 NEC

2.1 Article 90: Purpose, Scope, Arrangement & Enforcement 2.2 Navigating the Code Book: Structure, Index & Tabbing Strategy 2.3 Article 100 Definitions You Must Know Cold 2.4 Electrical Theory for the Exam: Ohm's Law, Power & Three-Phase

3 Chapter 3: General Requirements — Article 110

3.1 Approval, Listing, Interrupting Rating & Terminations 3.2 Temperature Limitations of Terminations — 110.14(C) 3.3 Working Space, Access, Egress & Illumination — 110.26(A) through (D) 3.4 Dedicated Equipment Space, Guarding & Over-1000-Volt Installations

4 Chapter 4: Conductors and Ampacity — Article 310

4.1 Conductor Types, Insulation Markings & Table 310.16 4.2 Ambient Temperature Correction and Alaska's Cold 4.3 Adjustment for More Than Three Current-Carrying Conductors 4.4 Putting It Together: Full Conductor-Sizing Problems 4.5 Parallel Conductors, Dwelling Service Sizing & Conditions of Use

5 Chapter 5: Wiring Methods and Materials — NEC Chapter 3

5.1 Article 300 General Requirements and Underground Cover 5.2 Thermal Movement: Expansion Fittings and Table 352.44 5.3 Boxes and Enclosures: Box Fill and Pull Box Sizing 5.4 Cable Assemblies: NM, MC, AC, SE, UF and TC 5.5 Raceways: RMC, IMC, EMT, FMC, LFMC, PVC and ENT 5.6 Conduit Fill: Chapter 9 Tables and Annex C 5.7 Cable Trays, Wireways, Busways, Gutters and Surface Raceways

6 Chapter 6: Branch Circuits and Feeders

6.1 Branch-Circuit Ratings, Conductor Sizing & Multiwire Circuits 6.2 Required Outlets and Receptacle Spacing in Dwellings 6.3 GFCI Protection — Article 210.8 6.4 AFCI Protection and Receptacle Requirements 6.5 Feeders and Outside Branch Circuits — Articles 215 and 225 6.6 Grounded Conductor Identification, Switches & Panelboards

7 Chapter 7: Overcurrent Protection — Articles 240 and 242

7.1 Article 240 Fundamentals: Ratings, Locations & Conductor Protection 7.2 Feeder Tap Rules — 240.21(B) 7.3 Transformer Secondary Conductors — 240.21(C) 7.4 Fuses, Circuit Breakers, Series Ratings & Article 242 Surge Protection

8 Chapter 8: Services and Load Calculations

8.1 Service Conductors, Clearances and Service Equipment 8.2 Service Disconnects, the 2020 Rule Change, SPDs and Service GFPE 8.3 Article 220 Part II: General Lighting, Receptacles and Demand Factors 8.4 The Standard Dwelling Calculation — Article 220 Part III 8.5 Optional Dwelling and Multifamily Calculations 8.6 Commercial and Industrial Load Calculations 8.7 Neutral Load Calculations and Harmonics — 220.61

9 Chapter 9: Grounding and Bonding — Article 250

9.1 System Grounding, 250.24 and the Main Bonding Jumper 9.2 The Grounding Electrode System — 250.50 through 250.53 9.3 Grounding Electrode Conductor Sizing and Installation 9.4 Bonding: Services, Metal Piping, Structural Metal and Other Systems 9.5 Equipment Grounding Conductors: Types, Sizing and Continuity 9.6 Separately Derived Systems and Separate Buildings 9.7 Ground-Fault Protection of Equipment and Grounding of Specific Equipment

10 Chapter 10: Equipment for General Use — NEC Chapter 4

10.1 Flexible Cords, Cables and Fixture Wires 10.2 Switches, Receptacles and Industrial Control Panels 10.3 Luminaires, Lampholders and Recessed Installations 10.4 Appliances and Fixed Electric Space Heating 10.5 Deicing, Snow Melting, Pipeline and Vessel Heating 10.6 Motors Part I: Full-Load Current, Conductors and Overload Protection 10.7 Motors Part II: Short-Circuit Protection, Controllers, Disconnects and HVAC

11 Chapter 11: Transformers, Generators and Special Occupancies

11.1 Transformers — Article 450 11.2 Generators, Storage Batteries and Energy Storage Systems 11.3 Hazardous (Classified) Locations — Articles 500 through 506 11.4 Garages, Hangars, Fuel Dispensing, Bulk Storage and Spray Application 11.5 Health Care Facilities — Article 517 11.6 Agricultural Buildings, Manufactured Homes, RV Parks and Marinas 11.7 Assembly, Theaters, Carnivals, Temporary Installations and Pools

12 Chapter 12: Special Equipment, Special Conditions and Exam Strategy

12.1 Signs, Cranes, Elevators, Electric Vehicle Charging and Welders 12.2 Solar Photovoltaic, Interconnection and Stand-Alone Systems 12.3 Wind Electric Systems and Fire Pumps 12.4 Emergency, Legally Required Standby, Optional Standby and COPS 12.5 Class 1, 2 and 3 Circuits, Fire Alarm, Optical Fiber and Communications 12.6 Cold-Climate Practice in Alaska: Code Basis and Engineering Judgment 12.7 Exam-Day Strategy: Navigation, Calculation Workflow and Time Management

6.3 GFCI Protection — Article 210.8

Key Takeaways Explain This Topic AI

A Class A ground-fault circuit interrupter trips when the ground-fault current is 6 milliamperes or higher and does not trip below 4 milliamperes.

NEC 210.8(A) requires GFCI protection for 125-volt through 250-volt receptacles supplied by single-phase branch circuits rated 150 volts or less to ground in eleven listed dwelling-unit locations, including all basements.

NEC 210.8(A)(7) requires GFCI protection for receptacles located within 6 feet of the top inside edge of the bowl of a sink.

NEC 210.8(B) extends GFCI protection to non-dwelling single-phase receptacles rated 150 volts or less to ground and 50 amperes or less, and three-phase receptacles rated 150 volts or less to ground and 100 amperes or less.

NEC 210.8(F) requires GFCI protection for outdoor outlets for dwellings supplied by single-phase branch circuits rated 150 volts or less to ground and 50 amperes or less, other than those covered by 210.8(A)(3).

Last updated: August 2026

What a GFCI Actually Does

A ground-fault circuit interrupter compares the current leaving on the ungrounded conductor with the current returning on the grounded conductor. In a healthy circuit they are equal. If some current is returning by another path — through a person, through water, through a damaged raceway — the difference appears as an imbalance, and the device opens the circuit.

A Class A GFCI is defined by UL 943 to trip when the ground-fault current is 6 milliamperes or higher and not to trip when the ground-fault current is less than 4 milliamperes . That range is set below the level at which a typical adult loses the ability to let go of an energized object.

Distinguish this from ground-fault protection of equipment (GFPE) , which operates at much higher levels — commonly 30 milliamperes for heating equipment, and up to 1200 amperes for the service GFPE required by 230.95. GFPE protects equipment and property , not people.

  • Device Typical trip Protects
  • Class A GFCI 4–6 mA People
  • GFPE (special-purpose) commonly 30 mA Equipment, fire prevention
  • Service GFPE (230.95) up to 1200 A, 1 second max at 3000 A Equipment, arcing burndown
  • 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 installed in the following locations shall have GFCI protection for personnel:

  • # Location Notes
  • (1) Bathrooms

(2) Garages and accessory buildings with a floor at or below grade level not intended as habitable rooms and limited to storage, work areas, and similar use

  • (3) Outdoors Exception for snow-melting or deicing equipment supplied by a dedicated branch circuit per 426.28
  • (4) Crawl spaces at or below grade level
  • (5) Basements 2020 change: all basements, finished and unfinished
  • (6) Kitchens
  • (7) Sinks — where receptacles are installed within 6 feet of the top inside edge of the bowl of the sink
  • (8) Boathouses
  • (9) Bathtubs or shower stalls — where receptacles are installed within 6 feet of the outside edge
  • (10) Laundry areas
  • (11) Indoor damp and wet locations

The basement change in the 2020 edition is significant: earlier editions limited the requirement to unfinished portions of basements. In the 2020 NEC, all basement receptacles in the listed voltage range require GFCI protection.

The expansion from 125-volt to 125-volt through 250-volt is the other major 2020 change. A 240 V receptacle for a dryer or a garage compressor in a listed location now requires GFCI protection.

Other Than Dwelling Units — 210.8(B)

All single-phase receptacles rated 150 volts to ground or less, 50 amperes or less , and three-phase receptacles rated 150 volts to ground or less, 100 amperes or less , installed in the following locations shall have GFCI protection:

Bathrooms

Kitchens — 2020 broadened this beyond commercial kitchens to any area with a sink and permanent facilities for food preparation and cooking

  • Rooftops
  • Outdoors
  • Sinks — where receptacles are installed within 6 feet of the top inside edge of the bowl of the sink
  • Indoor damp or wet locations
  • Locker rooms with associated showering facilities
  • Garages, service bays, and similar areas other than vehicle exhibition halls and showrooms
  • Crawl spaces at or below grade level
  • Unfinished portions or areas of the basement not intended as habitable rooms
  • Laundry areas

The ampere thresholds are the point to memorize: 50 A single-phase, 100 A three-phase .

Boat Hoists, Appliances and Crawl Space Lighting

210.8(C) Boat Hoists. GFCI protection shall be provided for outlets not exceeding 240 volts that supply boat hoists installed in dwelling unit locations.

210.8(D) Specific Appliances. GFCI protection shall be provided for the outlets that supply the following appliances rated 150 volts or less to ground and 60 amperes or less, single- or three-phase: automotive vacuum machines, drinking water coolers and bottle fill stations, high-pressure spray washing machines, tire inflation machines, vending machines, sump pumps , dishwashers , and electric ranges, wall-mounted ovens, and counter-mounted cooking units where the receptacle or outlet is in a listed location.

The dishwasher entry is a notable 2020 addition — a hardwired dishwasher outlet in a dwelling now requires GFCI protection.

210.8(E) Equipment Requiring Servicing. GFCI protection shall be provided for the receptacles required by 210.63 — the HVAC servicing receptacle.

210.8(F) Outdoor Outlets. All outdoor outlets for dwellings, other than those covered in 210.8(A)(3), that are supplied by single-phase branch circuits rated 150 volts or less to ground, 50 amperes or less, shall have ground-fault circuit-interrupter protection for personnel. Note that this says outlets , not receptacles — a hardwired outdoor heat pump or mini-split outlet falls under it. An exception in the 2020 text addresses lighting outlets other than those covered in 210.8(C).

Reading the Rule Precisely

Several traps recur:

Outlet versus receptacle. 210.8(A) and (B) apply to receptacles . 210.8(D), (E) and (F) apply to outlets , which includes hardwired equipment.

Measured from where. The sink rule measures 6 feet from the top inside edge of the bowl — not from the faucet, cabinet edge, or countertop edge.

Voltage to ground. A 240 V two-pole circuit from a 120/240 V system is 120 V to ground , so it is within the 150-volt-to-ground scope.

The location determines the requirement, not the load. A receptacle in a garage supplying a freezer needs GFCI protection; the 2020 edition removed the old dedicated-equipment exceptions for garages and basements.

Where Protection May Be Provided

GFCI protection may be provided by a GFCI receptacle , a GFCI circuit breaker , or a listed GFCI deadfront device feeding downstream outlets. 210.8 requires the protection to be readily accessible in the general text of the section for many applications — check the specific subsection language.

406.4(D)(2) requires that where a receptacle is replaced at a location now required to have GFCI protection by 210.8, the replacement receptacle shall be GFCI protected . This applies even in an existing installation wired under an earlier Code.

Nuisance Tripping and Long Runs

GFCI devices respond to leakage , and every conductor has some. Very long runs, wet raceways, and motor loads with capacitive filters all contribute. In cold climates, a heat-trace circuit is a classic source: moisture ingress in a damaged cable produces steady leakage that eventually reaches the trip threshold.

The Code's answer for deicing and snow-melting equipment is not to remove protection but to use the right kind : 426.28 requires ground-fault protection of equipment for fixed outdoor electric deicing and snow-melting equipment, and 427.22 does the same for fixed electric heating equipment for pipelines and vessels. Those are GFPE devices at a higher trip level, not Class A GFCIs. The receptacle exception in 210.8(A)(3) for snow-melting and deicing equipment on a dedicated branch circuit per 426.28 exists for exactly this reason.

Do not respond to nuisance tripping by removing required GFCI protection. Investigate the leakage, verify the equipment grounding conductor is intact, check for moisture in boxes and raceways, and separate long runs onto their own devices.