Installing Ground Fault Outlets - The Basics

A ground fault circuit interrupter, or GFCI, is an electrical device that is installed on a home’s branch circuit to help protect the individual from accidental electrocution. According to the U.S. Consumer Product Safety Commission, a properly installed ground fault outlet could prevent approximately two-thirds of the roughly 300 electrocutions that occur in American households each year. Before reading the instructions on how to properly install a ground fault outlet, use the information here to become more familiar with the device and how it works.

How Electrical Shock Occurs

Most electrical shock in the home happens around water and/or plumbing fixtures. The reason for this is that plumbing pipes are grounded. When an electrical appliance is leaking current, the current is basically escaping to ground although it doesn’t really have a set path. When someone touches the electrical appliance with one hand and touches a plumbing fixture (like a stainless steel sink) with their other hand, it gives the current a direct path to flow from the appliance, through individual, through the plumbing pipes and to ground.

Depending on the severity, the individual could suffer a startling shock, severe burns or electrocution. In some cases, the individual will be stuck in position, unable to break their hold on either the sink or the appliance.

How the GFCI Prevents Electrocution

A properly installed ground fault circuit interrupter constantly monitors the level of current that’s flowing through whatever circuit it is wired to. If the current fluctuates, even minutely, the ground fault circuit interrupter automatically stops the current from flowing through the circuit.

Here’s an example:

You place a toaster on your kitchen countertop and plug it in to the ground fault outlet. Unbeknownst to you, the toaster is faulty and a bare wire is touching the metal casing on the interior of the appliance, which electrifies the toaster’s metal fixtures. You place your toast in the toaster with your right hand while turning on the faucet with your left hand. When your right hand accidentally touches the exterior of the toaster, the current goes straight to ground and therefore trips the GFCI outlet instantaneously. You still may have felt a shock, but a fatal level of current was prevented.

Where Should Ground Fault Outlets Be Installed?

Ground fault outlets, in compliance with the National Electric Code, need to be installed in any damp or wet location. This includes garages, basements, bathrooms, kitchens, outdoors and crawl spaces.
This does not, however, mean that every outlet in the area needs to be changed over to a ground fault outlet. If the circuit is wired in series, meaning that the circuit is run from outlet to outlet, then only the first outlet in the series needs to be a ground fault circuit interrupter. All of the outlets wired beyond the GFI outlet will be protected.

An exception to the rule for GFI outlets in wet locations is the outlet that powers the garbage disposal. A garbage disposal motor causes a spike in amperage when it kicks on which will trip the GFI outlet every time, therefore, it needs to be wired directly or plugged into a regular outlet under the sink.

Part 1 | Part Two

Dave Donovan is a freelance copywriter living in Atco, NJ.  An electrician for 15 years, an injury forced him to pursue his true passion - writing.