Part of the problem Pros have involves answering questions for homeowners. Here's a question that comes up a lot: what are GFCI outlets, and where do they go? (Or why do we need them?) We brought in a few resident experts to help answer that question. We also dig into why you need a GFCI receptacle, breaker or receptacle in your home.
Table of contents
- Let's start with what is a GFCI receptacle?
- About ground fault
- Types of GFCI Devices
- Where to install GFCI
- Connect GFCI outlet
- Not too difficult, right?
Let's start with what is a GFCI receptacle?
GFCI stands for Ground Fault Circuit Interrupter. These are also called GFIs, or Ground Fault Interrupters. The GFCI precisely monitors the balance of current flowing through the circuit. If power goes where it shouldn't, in short, a GFCI cuts power instantly.
GFCIs prevent fatal electrical shock by eliminating the continuous current draw in the event of a short circuit. This is very different from receptacles such as arc fault circuit interrupters or Leviton AFCI receptacles. These can track down and stop slow electrical "leaks," such as those caused by puncturing wires through bedroom walls.
About ground fault
In and around the home, ground faults most commonly occur around water or moisture. Water and electricity are incompatible, and there are many places where both are close at hand, both inside and outside the home.
For the safety of your family, all switches, receptacles, circuit breakers and circuits in these rooms and areas of the home should be GFCI protected. What is a GFCI receptacle? It could be just what keeps your family safe in the event of a tragic electrical accident.
A ground fault represents any electrical path between a current source and a grounded surface. A ground fault occurs when AC current "leaks" and escapes to ground. How this happens is important. If your body provides a path for this leak to the ground, you could be injured, burned, severely shocked, or electrocuted. Since water is a very good conductor of electricity, ground faults are more likely to occur in areas near water. Water provides a conduit for electricity to "escape" and find an alternate route to the ground.
Types of GFCI Devices
While you may have come here asking what a GFCI receptacle is, there are actually three basic types of GFCI devices:
GFCI outlet
The most common GFCIs in residential use are GFCI receptacles. This inexpensive device replaces a standard socket (outlet). Fully compatible with any standard receptacle, it protects other receptacles "downstream" (any receptacle that receives power from a GFCI receptacle). This also explains the change from GFI to GFCI – referring to protected "circuits".

GFCI receptacles are generally "fattier" than standard receptacles and take up more space in a single or dual gang electrical box. New technology like the Leviton SmartlockPro Slim GFCI takes up less space than ever before. Wiring a GFCI receptacle is no big deal, but you need to do it correctly for the downstream protection to be effective.
GFCI circuit breaker
Professionals use GFCI breakers more frequently because they allow builders and electricians to use standard (inexpensive) outlets and install only one GFCI breaker in the panel box. A GFCI breaker has the advantage of protecting every fixture on the circuit—lights, outlets, fans, etc. They also provide overload and simple short circuit protection.

Portable GFCI for Outdoor Use
This is an outlet strip or other device that provides GFCI-rated protection in portable equipment. If you need GFCI protection for your appliance, but can't find a protected outlet, this will give you the same protection.

Where to install GFCI
Since about 1973, most outdoor receptacles built to comply with the National Electrical Code require GFCI protection. In 1975, NEC expanded it to include bathroom containers. In 1978, a garage wall outlet was added. Until around 1987, regulations did not include kitchen containers. Many homeowners find themselves redoing electrical equipment to comply with current laws. All outlets in crawl spaces and unfinished basements also require GFCI outlets or circuit breakers (since 1990).
Apparently, newer GFCI breakers make retrofitting a home with GFCI protection much easier than replacing every outlet in the system. For fuse-protected homes (seriously consider upgrading your box), stick with GFCI outlets. For upgrades, we recommend focusing on the most critical areas, such as bathrooms, kitchens, crawl spaces, and outdoor spaces.
Connect GFCI outlet
We have a separate article on wiring GFCI receptacles, but most savvy consumers will be able to wire them themselves as long as they follow the instructions. Just make sure to turn off power to the circuit breaker completely before starting. If you're at all unsure how to do this, hire a professional.
To test a GFCI outlet after installation, plug something into the outlet (such as a radio or light) and turn it on. Press the "TEST" button on the GFCI to make sure the "RESET" button pops out and the unit turns off. If the "RESET" button pops out but the light does not go off, the GFCI is not wired properly. If the "RESET" button does not pop out, the GFCI is defective and should be replaced. Press the "RESET" button to reactivate your circuit. You can also buy an inexpensive GFCI compliant circuit tester.
Not too difficult, right?
Ground fault circuit interrupters should be present in any home. When rewiring or updating your home to meet code, pay attention to where you place your GFCI outlets or circuit breakers. This affordable product can provide your family with a very beneficial level of security.