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.
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.
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.
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.
