A ground fault circuit breaker is properly called a ground-fault circuit-interrupter breaker, or simply a GFCI breaker. It installs into a home’s service panel, or breaker box to provides GFCI protection for the entire branch circuit it serves. This installation is commonly used as an alternative to installing GFCI receptacles (outlets) in specific locations where they are required by the local electrical code. GFCI protection aims at protecting users against accidental shock during circuit failures.
Building codes in most areas now require an additional type of protection against sparking for all general-use outlet circuits, known as AFCI protection. While GFCI protection aims to prevent shock, AFCI protection guards against sparking and resulting fire. Where you need to give a circuit both AFCI and GFCI protection, there are special dual-purpose AFCI/GFCI circuit breakers available, which is installed in the same way as a GFCI-only breaker.
Before You Begin
Service panels and breakers are made by many different manufacturers, and they are not universally compatible. When installing a new breaker, the breaker must match the brand and type of panel you have. Consult the breaker and/or panel manufacturer for recommendations.
The new breaker also must carry the appropriate voltage and amperage ratings for the circuit it will protect. Most standard branch circuits are rated for 120 volts and either 15 or 20 amps. Make sure the new breaker has an amperage size appropriate for the circuit: 15 amps for circuits wired with 14-gauge wire, 20 amps for circuits wired with 12-gauge wire.
Installing a circuit breaker involves working near equipment carrying potentially deadly voltage. While the main circuit breaker and all of the branch circuits in the service panel will be shut off for the GFCI breaker installation, the incoming conductors from the utility service and the lugs (terminals) where the conductors connect to the panel remain live at all times. Never touch the service lines or the lugs while working in the service panel.
Standard vs. GFCI Breakers
Both standard and GFCI breakers are single-pole breakers that occupy one slot on a service panel and connect to the “hot” circuit wire, usually a black wire. The main difference between the two types of breakers involves the neutral connection. With a standard breaker, the neutral circuit wire (usually white) connects to the neutral bus bar on the service panel; it does not connect to the breaker. But with a GFCI or AFCI/GFCI breaker, the neutral circuit wire connects instead to a neutral terminal on the breaker. The GFCI or AFCI/GFCI breaker also has short, coiled, white neutral wire preinstalled on the breaker; this pigtail connects to the neutral bus bar in the service panel.
It’s critical that you connect the hot circuit wire to the “hot” or “load” terminal on the GFCI breaker and the neutral circuit wire to the neutral terminal. Mixing these up reverses the polarity of the circuit and may mean the breaker does not provide GFCI protection to the circuit—even if the breaker’s test button works normally.
When to Call a Professional
Although the technical skills required for installing a GFCI or AFCI/GFCI circuit breaker are fairly simple, the potential for fatal shock means this is a project that you should not attempt if you aren’t entirely confident of your DIY electrical skills. And in some areas, local codes do not allow unlicensed homeowners to do this work.
Call a licensed electrician if your code requires it, or if you’re not completely confident in your abilities. This is a basic, affordable service call that should take the electrician less than an hour to complete.
Watch Now: How to Install a Circuit Breaker
Source: The Spruce