Ground Fault Circuit Interrupter's

Ground Fault Circuit Interrupters (GFCI) are the outlets that typically have black and red test buttons on them. GFCI outlets are intended to shut down the electricity to that outlet and other protected outlets when a shock hazard is detected in the electrical system. These safety outlets should be present near all sources of water and near metal-encased appliances that do not have electric motors (such as a cook top, oven, coffee maker, toaster, etc.). GFCI-protected outlets are outlets that are "downstream" of GFCI outlets, meaning that they are on the same circuit as a GFCI outlet and being "monitored" by that GFCI. If there is no electricity to a protected outlet, the GFCI outlet at a separate location might have tripped and disconnected electricity to the circuit. Typical areas where you might find GFCI or GFCI-protected outlets include garage, laundry, kitchen, bathrooms, and exterior locations. Usually the kitchen GFCI outlet will control any other outlets in the kitchen (sometimes more than one GFCI outlet is present in the kitchen). Sometimes all the bathroom outlets are placed on the same circuit, with only one GFCI outlet protecting the outlets in all the bathrooms. Occasionally a GFCI outlet in the garage will protect outlets in various bathrooms. Such garage installations can be inconvenient, particularly in multi-story buildings.

How does a GFCI outlet operate?

This is the simplified "layman's terms" version:

Picture a little electrician living in the GFCI. He watches the electricity come in over one shoulder and go out over the other shoulder. If there's no difference, he just sits there. If a difference is created, (you drop your shaver or hair dryer into the tub or sink), he immediately shuts down the electricity attempting to keep you from being shocked. He is very sensitive and can detect the slightest difference.

The problem with this little electrician is that he likes fishing. One of these days, he is going to get up and go fishing. When he does, he isn't coming back. The only way you're going to know if he is still in there is to test the outlet or breaker every 30 to 45 days.

How do I test them?

To test the GFCI outlet, first plug a nightlight or lamp into the outlet. Turn the light on, and then press the "TEST" button on the GFCI outlet. The GFCI outlet's "RESET" button should pop out, and the light should go out. If the GFCI outlet is functioning properly, meaning that the light does go out, press the "RESET" button to restore power to the outlet. If the "RESET" button pops out but the light does not go out, either the GFCI outlet is not working properly or it is incorrectly wired. Call a qualified electrician to evaluate the problem.
You should test the GFCI outlets as soon as you move in to a house, noting at the same time any protected outlets that may be present and which GFCI outlets control those protected outlets; typically the protected outlets should be labeled as such. Although they are proven life-saving devices, GFCI's are known to fail on a regular basis and should be tested monthly to ensure that they are functioning properly. If GFCI outlets trip regularly, consult a qualified electrician immediately to determine why the tripping is occurring.

Nuisance tripping of GFCI devices was common several years ago; however, nuisance tripping issues have been corrected on all current generation GFCI devices and the reliabilty of the devices has increased.  Nuisance tripping no longer occurs even for sump pump circuits, hair dryers, and refrigeration circuits.  If a GFCI device is tripping continually, a safety problem exists and a qualified electrical contractor should be consulted.

I never had those in my house!

Some of the currently required locations for GFCI's may not have been required when your house was constructed, however, it is recommended that all outlets needing ground fault protection, as recognized by the newest national safety standards be upgraded. We also recommend that a licensed electrician complete this upgrade. Safety standards and codes are set for a reason; they save lives! These safety codes are always being improved upon as knowledge increases and technology improves.

The following dates indicate when nationally accepted minimum safety standards required GFCI protection. The local minimum safety standards may have adopted this protection at an earlier or later date.




  • 1971 Receptacles within 15 feet of pool walls
  • 1971 All equipment used with storable swimming pools
  • 1973 All outdoor receptacles
  • 1974 Construction Sites
  • 1975 Bathrooms, 120-volt pool lights, and fountain equipment
  • 1978 Garages, spas, and hydro massage tubs
  • 1978 Outdoor receptacles above 6ft. 6in. grade access exempted
  • 1984 Replacement of non-grounding receptacles with no grounding conductor allowed
  • 1984 Pool cover motors
  • 1984 Distance of GFCI protection extended to 20 feet from pool walls
  • 1987 Unfinished basements
  • 1987 Kitchen countertop receptacles within 6 feet of sink
  • 1987 Boathouses
  • 1990 Crawlspaces (with exception for sump pumps or other dedicated equip.)
  • 1993 Wet bar countertops within 6 feet of sink
  • 1993 Any receptacle replaced in an area presently requiring GFCI
  • 1996 All kitchen counters - not just those within 6 feet of sink
  • 1996 All exterior receptacles except dedicated de-icing tape receptacle
  • 1996 Unfinished accessory buildings at or below grade
  • 1999 Exemption for dedicated equipment in crawlspace removed
  • 2005 Laundry and utility sinks
  • Exemptions and additions continue with each revision of the National Electric Code.  This list should not be considered final or definitive.