What Is a GFCI and Do I Need GFCI Outlets in My Home?

A current that strays from an appliance or a wire or that contacts water can deliver a jolt that causes serious injury or even death. Each year in the U.S., more than 4,000 people are wounded by an electrical shock, and another 400 are killed. Electrical fires further result in an estimated $1.6 billion in annual property damage.

For this reason, today’s National Electrical Code (NEC) requires ground-fault circuit interrupter (GFCI) devices to protect us from possible electrical-current hazards. Efficient and inexpensive, they are mandatory in all new homes and in renovations of older homes in Oswego, Yorkville, Naperville, Aurora and Plainfield.

GFCIs detect imbalances in currents and respond to them by rapidly shutting off the power to prevent a shock. To achieve this, they measure the current on the hot side of the source to the output current on the neutral side. A difference of even a few milliamps in current indicates leakage, prompting the GFCI to react within 20 to 30 milliseconds.

As but one example, if you are cutting a roast with an electric knife near a sink where another person is washing dishes and the appliance slips from your hand into the sink, the GFCI outlet will cut the power before stray current can cause potential harm.

GFCI protection is provided either at the outlet, which you can identify by the “Test” and “Reset” buttons, or at the distribution panel through a GFCI circuit breaker, which guards all outlets on the circuit it controls. Other outlets can be protected downstream of the local outlet type with push buttons by wiring the added outlets to the load side of the local GFCI device.

With this in mind, it is not always possible to tell if an outlet is GFCI protected or not simply by looking at it. If an outlet doesn’t seem to be providing power, be sure to check the circuit breakers as well as any GFCI outlets with push buttons in the area.

Where GFCI Outlets Are Needed in the Home

The NEC requires GFCI outlets in any location where an outlet is six feet or closer to a plumbing fixture or other moisture source in residential dwelling units, including but not limited to:

  • kitchens and bathrooms
  • garages and accessory buildings
  • all exterior outlets
  • crawlspaces
  • unfinished basements
  • laundry, utility and wet bar–sink areas
  • pool, spa and hot-tub outlets
  • boathouses

A few exceptions to requirements for GFCI devices can include:Local building authorities may also have their own electrical-safety requirements beyond the NEC’s, so compliant, responsible outlet installation and wiring will always include verification of local codes.

  • freezer and refrigerator outlets, which can trip without your knowledge
  • exterior outlets that are not readily accessible and are supplied by a dedicated branch circuit for electric snow-melting or de-icing equipment
  • in unfinished basements, outlets that supply power only to a permanently installed fire- or burglar-alarm system, that are not readily accessible or that are on a dedicated branch circuit and labeled for use with plug-in equipment such as a sump pump

Testing Your GFCI Outlets at Home

On occasion, a GFCI outlet can fail, leaving the circuit without power or without protection from ground faults. That’s why it is important to test your GFCI outlets at intervals, ideally once a month.

To test your GFCI outlets for proper function:

  • Press the “Test” button, which should turn off the circuit.
  • Make sure the power is off by plugging something in (lamp, radio, etc.); then unplug it.
  • Press the “Reset” button, which should turn the circuit back on.
  • Check the power by plugging your device back in.

If any of your GFCI outlets fail this test, promptly alert a professional electrician.

Your Local Resource for GFCI Information and Installation

Trinity Electrical Services provides professional electrical knowledge and support for homeowners in Oswego, Yorkville, Naperville, Aurora and Plainfield. If you would like to further discuss what a GFCI outlet is, why you need them in your home or how you can have one installed or replaced, contact us at (630) 499-1492. We’ll be glad to assist you.

Trinity Electrical Services is also a resource for other Chicagoland suburbs such as Plano, Montgomery, Batavia, North Aurora and Sugar Grove.


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