We have probably all heard the terms GFCI and AFCI when it comes to electrical safety, but what do the letters stand for? And how do these letter-heavy, acronym-named devices help keep us safe?

GFCIs

GFCIs, or ground fault circuit interrupters, help protect against electrical shock and electrocution. It is important to test and reset the red outlet (GFCI) buttons monthly to ensure they are working properly. GFCIs are typically installed in outlets or circuits close to water sources in and outside of the home.

When they are in working order, GFCIs help prevent shock by detecting current variations along the electrical path. If a person’s body starts to receive a shock because of current variations, the GFCI senses this and cuts off the power.

According to the National Electrical Code, a “ground fault” is a conducting connection (whether intentional or accidental) between any electric conductor and any conducting material that is grounded or that may become grounded.

In other words, a ground fault happens when an electrical circuit malfunctions, causing the electrical current to seek a path to ground other than through the intended wires. A human or animal in the wrong place at the wrong time could become that “path to ground” or conduit of electricity.

AFCIs

AFCIs, or arc fault circuit interrupters, are required by the National Electrical Code for some, but not all, electrical circuits in the home. The device breaks the circuit when it determines a dangerous electrical arc, which is a discharge between two electrodes that can cause intense heat or light. The extreme heat of an arc can cause a fire, so that is why AFCIs are required by code.

Most people associate arcs with welding, but they can happen in the home or when the conductors on a power line are interrupted, such as when a tree falls on it or a car strikes a utility pole and the line falls.

Much like a GFCI is to a ground fault, the AFCI breaks the circuit when it detects an arc or abnormalities in the flow of electricity. That safeguard or break in circuit helps prevent a fire or other arc-related electrical damage. The temperatures of an arc can exceed 10,000 degrees.

An AFCI can distinguish between insignificant, harmless arcs and the undesirable kind that could start a fire or cause damage. Benign or uneventful arcs can be an everyday byproduct of using switches and plugs in good working order.

What are arcs and ground faults, again?

So, in review, an arc fault is the unintended result of current flowing through an unplanned path. A significant arc can cause burning particles that can easily ignite the materials around it, drywall, insulation or wood.

And a ground fault? A ground fault happens when stray electricity takes an unintentional pathway and the current flows directly to the earth, into the ground. If you become part of that path, the result could be shock or electrocution.