Where should I NOT use a GFCI or AFCI?

Question

There is a lot of information out there about the benefits of GFCI and AFCI and the places where they must or should be used. But are there any circumstances where you're better off without them? If I won a free box of dual-function GFCI/AFCI breakers, would there be any reason not to use one for every circuit in my house?

Answer 1

For all new construction residential dwellings the answer is not too complicated.

For older homes with existing wiring the answer is not as easy. A qualified electrician would need to assess the wiring conditions and even then only by trail and error could they determine if ARC-fault protection would be able to work. In some cases using an ARC-Fault receptacle downstream may be an option, whereas a complete rewire of the existing branch circuit may be needed.

I've elaborated on the answer breaking it up into residential and commerical establishments for educational purposes.

Residential AFCI Requirements

• All habitable rooms that contain 120 volt 15 or 20 Amp branch circuits require ARC-fault protection. This includes kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, or similar rooms or areas.

• Exceptions:

  • Bathrooms, unfinished basements, garages, and outdoors.
  • Fire alarm system installed in accordance with 760.41( B) or 760.121( B) is installed in RMC, IMC, EMT, or steel-sheathed cable, Type AC or Type MC, meeting the requirements of 250.118, with metal outlet and junction boxes, AFCI protection shall be permitted to be omitted. (This is mainly in condominiums and not so much in traditional houses.)

  • Existing installations are not required to be updated with ARC-fault protection unless modification to the wiring is done.

    • Exception: AFCI protection shall not be required where the extension of the existing conductors is not more than 1.8 m (6 ft) and does not include any additional outlets or devices.

Residential GFCI Requirements

• All 125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms, even if the receptacle is part of the bathroom lights, or if you have a washing machine in the bathroom it too requires GFCI protection.
• Garages, sheds, and accessory buildings located at or below grade.
• All outdoor receptacles.
• All crawl space receptacles.
• All unfinished basements.
• All kitchen countertop areas.
• All dishwashers.
• All pool motors, spas, and pumps
• All receptacles within 6' of any sink.
• All boathouses
• All laundry areas
• Exceptions:
  • A receptacle supplying only a permanently installed fire alarm or burglar alarm system shall not be required to have GFCI protection.
  • Receptacles that are not readily accessible and are supplied by a branch circuit dedicated to electric snow-melting, deicing, or pipeline and vessel heating equipment shall be permitted to be installed in accordance with 426.28 or 427.22, as applicable.
  • Receptacles installed for disposals and trash compactors are not required to be protected by GFCIs. A receptacle( s) installed behind a refrigerator is installed to supply that appliance, not the countertop, and is not covered by the kitchen countertop GFCI requirement.

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Commercial ARC-fault Requirements

• Dormitory units are required to have ARC-fault protection.

Commercial GFCI Requirements

• All 125-volt, single-phase, 15- and 20-ampere receptacles installed in bathrooms, kitchens, rooftops and outdoors, 6' from a sink, indoor wet locations, locker rooms, garages, service bays, and similar areas.
• All vending machines.
• All pool motors, spas, and pumps.
• All electric drinking fountains.
• Exceptions:
  • In industrial laboratories, receptacles used to supply equipment where removal of power would introduce a greater hazard shall be permitted to be installed without GFCI protection.
  • For receptacles located in patient bed locations of general care or critical care areas of health care facilities other than those covered under 210.8( B)( 1), GFCI protection shall not be required.
  • Receptacles that are not readily accessible and are supplied by a branch circuit dedicated to electric snow-melting, deicing, or pipeline and vessel heating equipment shall be permitted to be installed in accordance with 426.28 or 427.22, as applicable.
  • In industrial establishments only, where the conditions of maintenance and supervision ensure that only qualified personnel are involved, an assured equipment grounding conductor program as specified in 590.6( B)( 2) shall be permitted for only those receptacle outlets used to supply equipment that would create a greater hazard if power is interrupted or having a design that is not compatible with GFCI protection.

Answer 2

GFCIs will often nuisance trip with certain types of loads. For example many motors will trip the GFCI even though there is no leakage to ground. This is why there is an exception for the refrigerator's outlet. It's a good idea to have that on a circuit of it's own with no GFCI.

A GFCI device doesn't generally measure leakage to ground, it compares the current on the hot leg to the current on the neutral leg. Normally the same amount of current should go out as comes back. The premise is, if more current is seen on the hot than the neutral, it is assumed that some current is leaking to ground rather than returning on the neutral - which could mean someone is getting electrocuted - so the device interrupts the current.

I have heard that in some countries (maybe Australia?) there are different grades of GFCI, some are rated for use with motors and inductive loads.

Now AFCI - that one I can't say, I haven't tested it myself firsthand, but a lot of knowledgeable people claim that unlike GFCI, AFCI devices just don't work as intended.

Answer 3

National Electrical Code 2014 requires ground-fault protection for personnel in dwelling units for all 120 volt, single phase, 15 and 20 ampere receptacles installed in the following locations:

• Bathrooms.
• Garages
• Accessory buildings with floors at or below grade that are not intended as habitable rooms.
• Outdoors, except where receptacles on dedicated circuits are not readily accessible, and are used to supply snow-melting, deicing, or pipeline and vessel heating equipment.
• Crawl spaces
• Unfinished basements, unless the receptacle is on a dedicated circuit and used to supply a burglar alarm.
• Kitchens where the receptacles serve coutertop surfaces.
• Where a receptacle is within 6 ft. (1.8m) of sinks in other than kitchens.
• Boathouses
• Where receptacles are installed within 6 ft. (1.8m) of the outside edge of bathtub and shower stalls.
• Laundry areas

Arc-fault protection is required in dwelling units for all 120 volt, single phase, 15 and 20 ampere branch circuits supplying outlets and devices installed in:

• Kitchens
• Family rooms
• Dining rooms
• Living rooms
• Parlors
• Libraries
• Dens
• Bedrooms
• Sunrooms
• Recreation rooms
• Closets
• Hallways
• Laundry areas
• and all similar rooms and areas

I don't know where you shouldn't install them, I only know where you are required and not required to. I guess you shouldn't install them anywhere they're not required, or you'd be spending money you're not required to spend?

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According to the documentation for QO® and QOB Miniature Circuit Breakers, Qwik-Gard GFCIs should not be used as follows:

• Do not connect to swimming pool equipment installed before adoption of the 1965 National Electric Code
• Do not connect to electrical ranges or clothes dryers whose frames are grounded by a connection to the grounded circuit conductor.
• Do not use as a main circuit breaker in a panelboard or in reverse connected (backfed) applications.

Answer 4

A GFCI cannot be used where two circuits have a shared neutral line. It is rare, and probably violates all versions of the National Electric Code since 1970, or earlier, but I encountered a situation where I installed a GFCI circuit breaker in a bathroom outlet circuit in a house that was built around 1958. The GFCI kept tripping every hour or two for no apparent reason, so I removed it and replaced it with the original circuit breaker. Later, while performing remodeling that involved removal of drywall, the cause became apparent. Pinching pennies, the builder's electrician had connected the neutral wire to the refrigerator outlet in common with the neutral to the bathroom outlet, instead of running separate neutral and hot wires from the two circuit breakers in the main breaker panel to the two outlets. Each time the compressor motor in the refrigerator started, it created a current imbalance in the bathroom GFCI breaker, causing it to trip.

Answer 5

Do not install GFCIs for dedicated fridge outlets (the fridge does however need to be AFCI'ed - if it's new work).

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According to @Tester101's answer (drawing from the 2014 NEC) there are two exceptions.

GFCI required:

• Outdoors, except where receptacles on dedicated circuits are not readily accessible, and are used to supply snow-melting, deicing, or pipeline and vessel heating equipment.

• Unfinished basements, unless the receptacle is on a dedicated circuit and used to supply a burglar alarm.

From what I can tell (I do not have a copy of the 2014 NEC), these are the only two exceptions to the need of either a GFCI or an AFCI - for new work. Apparently, all other locations that do not require GFCIs, require AFCIs - for new work.

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IMO, you should not arbitrarily swap out outlets; old work only has to have complied with code at the time of installation. However, I see little reason not to swap out any and all convenience outlets to GFCI's (if you want to). Unless required by code for the new work I'm doing, there's no way I'd put hundreds of dollars worth of food on a GFCI outlet that's dedicated to a fridge.

Code jargon aside, the OP asked for any reason you wouldn't want either type of outlet installed. My number one concern about them failing is the spoiled food you'll have in your fridge while trying to better protect an outlet that you'd have to pull the fridge out to use otherwise.

IMO, this is the one place "you are better off without one."

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All statistics are to be taken with a grain of salt; mildly relevant:

Each year, there is an estimated average of 60 electrocutions associated with consumer products. –www.esfi.org

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CDC estimates that each year roughly 1 in 6 Americans (or 48 million people) get sick, 128,000 are hospitalized, and 3,000 die of foodborne diseases. –www.cdc.gov

Pick your poison.

Answer 6

Modern electrical code does not restrict installation of GFCI everywhere. All modern, quality equipment should not have enough leakage to trip GFCI.

You can't install GFCI if equipment you're using is old or poor quality and leakage current is enough to trip GFCI (constantly or intermittently). IMO it is better to fix or replace the equipment, but that's another story.

In summary, where fear of negative effects of accidental trip of GFCI circuit would outweigh benefits of this protection. Usual debate case that I've encountered: refrigerators, sump pumps, and other critical equipment. This is a matter of opinion, however, so you should make a decision for yourself. I'm just a dude with an internet connection.