Ground-fault circuit-interrupter (GFCI) protection has been in the National Electrical Code^® (NEC^®) for 50 years.  Many thought there could not possibly be any additional locations where GFCI protection was needed, but the 2011 edition shows that there are still areas that can benefit from this protection. Actually, new GFCI requirements have been added in every edition since 1971, but most people are only aware of those specified in 210.8. This article looks back at the history of GFCI requirements. Although Articles 210, 590 and 680 — those that have the longest history — are the focus, other notable requirements are included. Also, Code terminology has changed over the years; the terms used will be from the edition referenced.

The Protection Technique Arrives.

The first mention of ground-fault protection occurred in the 1962 NEC with the introduction of Article 680 for swimming pools. It is generally accepted that electricity and water are not a good combination, and there was a concern for the shock hazard associated with underwater lighting. An approved fail-safe ground detector device could automatically de-energize the circuit for underwater lighting operating at greater than 30 volts. This fail-safe ground (not yet called GFCI) detector was not the only allowable method; an approved grid structure or similar safeguard was an alternative.

A 1965 modification to the Code required all underwater lighting fixtures to perform reliably under any likely combination of fault conditions to prevent a shock hazard. Four methods could accomplish this requirement, including the use of “differential type circuit protection”, the precursor to the term “ground-fault circuit interrupter.”

What Is GFCI?

The definition of Ground-Fault Circuit Interrupter appeared in Article 680 (in the 1968 edition) as “a device whose function is to interrupt the electric circuit to the load when a fault current to ground exceeds some predetermined value that is less than that required to operate the overcurrent protective device of the supply circuit.” GFCI was still only one of the protection methods permitted for underwater fixtures. An interesting requirement was that conductors on the load side of the GFCI device were to be kept entirely independent of all other wiring and electrical equipment.

It was not until 1971 that GFCI protection became a “required” protection method. Even though underwater lighting fixtures were the first allowed this protection they were not the first required to have it. A failed grounding connection presents an electrical hazard, particularly with the number of handheld power tools and extension cords used around a construction site. So the first GFCI requirement (first simply because it occurred in Section 210-7) was for all single phase, 15- and 20-ampere receptacles used at a construction site. A few sections further, GFCI protection was required for all outdoor 120-volt, 15- and 20-ampere receptacles in residential occupancies, essentially for the same reason as for construction sites. This section also specifically permitted GFCI protection for “other circuits, occupancies and locations” if added protection was desired. In Article 680, protection included all electrical equipment used with storable pools and all receptacles within 15 feet of an indoor pool . The expansion of GFCI protection had begun.

Section 210-8 Arrives

The section titled “Ground-Fault Circuit Protection” debuted in 1975 for residential occupancies and construction sites. That year, because of the potential shock hazard, residential bathroom receptacles joined the list of locations requiring GFCI protection. At construction sites, the provision now applied only to 120-volt receptacles not part of the permanent wiring; but with prevalence of generators, an exception was granted for receptacles on portable generators of 5 kW or less. The GFCI requirements around pools continued to expand to lighting fixtures and outlets within 16 feet of the pool. Many pools were being added to dwellings in the 70s, so a retroactive provision covered existing fixtures and outlets within 5 feet of a newly installed pool. Finally after 12 years of using various protection methods, GFCI protection became the only method permitted for re-lamping underwater lighting fixtures. In 1975, mobile homes and recreational vehicles (Articles 550 and 551) began to parallel the GFCI requirements for residential occupancies, and GFCI protection came to health care facilities (Article 517).

Ground-fault circuit-interrupter protection requirements took time to expand. Concerns about the new technology, false tripping, financial burden, and the lack of data were cited as reasons. Still, 210-8(a) of the 1978 NEC added GFCI requirements to garages of dwelling units, partially due to concern with the amount of grounded (concrete) surface, and the fact that many hand-held tools did not have an equipment grounding conductor (for the younger crowd who have only used double-insulated ABS tools, metal used to be the hand-held power tool housing material of choice). Data regarding a grounding system that was verified as being intact supported the addition of an exception to the 210-8(b) construction site requirements. This exception introduced the assured grounding program as an alternative to GFCI protection. GFCI protection also became a requirement for marina receptacles (Article 555).

More Exceptions

Exceptions for garage receptacles that were not accessible — or were used for appliances in a dedicated space — first appeared in 1981. Thirty years ago, many appliances had high leakage currents, and ones with motors often were capable of tripping a GFCI device; therefore, fixed appliance locations were exempted. Non-accessible receptacles — such as on the ceiling for a garage door opener — were likewise exempted, with the expectation that the receptacle would not be used with extension cords or hand-powered tools.

In the 1984 edition, 210-8(b) was changed to address hotel and motel bathrooms, because those bathrooms present the same hazards as dwelling bathrooms. Construction projects are temporary conditions, so the GFCI requirements for these areas previously in 210-8(b) were relocated to Article 305, Temporary Wiring.

The GFCI requirements expanded in 1987 to additional dwelling unit receptacles. The Code required the installation of at least one receptacle in a basement. With the concrete and portable tool use in this area, GFCI protection became a requirement for that one receptacle. The intent of the wording “above the countertop and within 6 feet of a kitchen sink” was clarified to exempt appliances (disposal, refrigerator, etc.) from the GFCI requirement. Additionally, dwelling boathouses (due to the nature of the location and the use of portable tools) became another protected location. The receptacles in commercial garages (Article 511) were included for the same reasons as those in a dwelling unit garage.

All receptacles in crawl spaces and “unfinished” basements appeared as 210-8(a)(4) in the 1990 edition, with exemptions for a single appliance, a laundry circuit, and a permanently installed sump pump. The substantiation for these exceptions was similar to that for the garage exemptions discussed above.

More Locations Get Protection

Section 210-8(a)(5) was modified in 1993 to apply to receptacles that serve — as opposed to being above — the kitchen countertop, and to add wet bar sinks. This edition introduced Section210-8(b), “Other than Dwelling Units” when the title was changed from ”Hotels and Motels.”  This title change added the GFCI requirement to the bathroom of every occupancy. The Code required HVAC service receptacle could be located on a roof, thus rooftop receptacles became 210-8(b)(2). To provide protection not initially installed, receptacles being replaced (210-7) were to be replaced with a GFCI receptacle, if GFCI protection was required by the current Code. The hazards at a construction site are the same whether the supply circuits are temporarily or permanently wired, so any receptacle used there required GFCI protection (Article 305).

In the 1996 NEC, dwelling unit grade-level unfinished accessory buildings, and every kitchen counter-top receptacle (not just those within 6 feet of the sink), were added to the list of locations requiring GFCI protection. Also added was the exception for snow-melting equipment receptacles that were not readily accessible. New Article 552 for park trailers tracked the GFCI requirements for mobile homes.

Many pool pumps at private clubs and apartment complexes are hard-wired, and these pools are often maintained by personnel not familiar with bonding and grounding requirements. The concern for protection of the public using these facilities warranted adding the GFCI requirement in the 1999 Code to 125- or 240-volt, 15- and 20-ampere pool pump motors, whether they were direct connected or cord-connected. This edition also brought another change to temporary installations (which were at that time in Article 305) when it expanded GFCI requirements to cover 125-volt, 30-ampere receptacles as well as any other receptacle used temporarily.

Kitchen receptacles in all non-dwelling units were added to 210.8(B) in 2002. The 5 kW or less generator receptacle exemption was dropped in this edition, thereby placing the GFCI requirement on all generators used at construction sites (moved to Article 527 at this point). Article 680 now addressed both dwelling and other than dwelling unit pump motors, but the requirement only applied to receptacles rated 120 through 240 volts, 15 or 20 amperes. Two new articles (647 and 682) added GFCI protection for receptacles for sensitive electronic equipment and for receptacles within the datum plane of bodies of water.

Sinks, Kitchens and Other Locations

Utility and laundry sinks very often do not have a countertop associated with them. Therefore, a 2005 revision removed the countertop criteria for wet bar, laundry, and utility sinks, thereby requiring GFCI protection for any receptacle within 6 feet of these dwelling unit sinks. “Commercial and institutional” were added as qualifiers for application of the GFCI requirements in other than dwelling unit kitchens. These kitchens were distinguished from others by adding what was to become the definition of a kitchen (“an area with a sink and permanent facilities for food preparation and cooking”). In 210.8(B), outdoor receptacles accessible to the public were required to have protection. Article 680 added all 125-volt receptacles within 20 feet of storable pools to the growing list of spaces requiring protection. This edition clarified that GFCI protection at temporary installations (finally Article 590) included both service and on-site generator supplied receptacles. Carnivals and fairs (Article 525) listed locations where GFCI is required, is not required, and is not permitted. Vending machines (Article 422) without integral GFCI had to be connected to a GFCI protected outlet.

Rules Tighten and Exceptions Disappear.

Initially a freezer may be plugged into a garage receptacle, but there is no assurance that a new owner will do the same; it is common to see extension cords plugged into the ceiling receptacle intended for a door opener. The new owner using these receptacles for power tools does not have the required protection. Neither of these conditions were anticipated when the exceptions appeared in 1981. The 2008 edition saw the 210.8(A) exceptions (except those for fire or burglar alarm systems) removed for garages and unfinished basements. This edition also tightened non-dwelling unit requirements to cover all kitchens and outdoor locations. It also covered all receptacles within 6 feet of any sink in non-dwelling units, with exceptions for industrial laboratories and patient care areas. The GFCI requirement for pool pumps reverted back to its earlier form — to cover cord-and-plug units as well as those with a direct connection. Ground-fault circuit-interrupter protection was included for all receptacles under new Article 626, Electrified Truck Parking Spaces.

Where Are We Today?

This brings us to 2011 where, rather than periodically adding locations where a sink might be present, receptacles within 6 feet of any sink (other than in a kitchen) require GFCI protection. There are three non-dwelling areas that were missing GFCI protection prior to the 2011 NEC: indoor wet locations such as inside a car wash , locker rooms with shower facilities. (wet persons using an electric hair dryer or shaver in this area needed protection), and garages [which may become wet with snow, rain, even spilled fluids, and in which portable tools and lighting or diagnostic equipment are used].  The garages covered by this new requirement are not the commercial garages covered under Article 511.  For temporary installations (Article 590), the GFCI requirement is also placed upon all 125-volt and 125/250-volt, 15-, 20-, and 30-ampere receptacles of a generator 15 kW or less.

After 50 years, it is impossible to know how many lives have been saved or injuries avoided since the introduction of GFCI requirements in the NEC. One thing for certain is that GFCI devices have helped accomplish the purpose of the NEC; the practical safeguarding of persons from hazards arising from the use of electricity.

Christopher D. Coache is Senior Electrical Engineer at NFPA where he is primarily involved with electrical codes and standards. He serves as staff liaison for NFPA 73, NFPA 110 and NFPA 111.  He has been involved in electrical safety for 25 years and has participated in the development of national and international standards.