The world of electricity is filled with acronyms and abbreviations. Very frequently two terms are confused with one another – these are GFCI and AFCI. Both refer to a special type of electrical protection in a plug, circuit or breaker.
Ground Fault Circuit Interrupters (GFCI) help prevent burns, electric shocks and electrocution. A GFCI has sensors that measure the current going out and the current coming back in. Normally, the current is balanced as it goes out and comes back in. However, if the current is out of balance, something is wrong. The GFCI senses any out of balance current/flow instantly shuts down the circuit, stopping the flow of electricity. Since water is an excellent electric conductor, GFCIs are important in areas where water and electricity could meet; current codes require that GFCI protection be present in kitchens, bathrooms, exterior plugs, laundry rooms, pool areas and garages. There are one of two ways to go about it: (1) install GFCI plugs in these areas, and/or (2) put these plugs and devices on a GFCI protected circuit, either with a GFCI plug as the first item on the circuit to protect everything downline (“virtual ground”), or have the circuit be controlled by a GFCI breaker.
Arc Fault Circuit Interrupters (AFCI) help prevent electrical arcing and fires. Electricity can leak out of damaged or decaying wires and start a fire, and these fires spread quickly in the wiring behind walls. AFCIs sense that electricity is leaking from the electric system and shuts electricity off before overheating happens.
It is much like a GFCI outlet, but it protects against an entirely different potential danger. Sometimes, certain types of electrical appliances will be used to convert electricity into heat. These devices can also cause heating where the device plugs into the wall. This is called arcing. You sometimes see it when you quickly unplug a heating appliance, like a clothing iron, from an outlet while it is switched on. Electrical arcs can also be caused by mice or squirrels who like to chew on electrical wiring.
An AFCI device will detect any ‘arcing’ (i.e. sparks, where electricity is being conducted through the air and converted to heat when you don’t want it to) and shut down the outlet before any damage can be done.
More recently, for new home building, there now exist combination GFCI/AFCI combination breakers which can be used for any circuit in your home, and they will detect both ground faults and arcs. They are much more expensive, as it is newer technology, but as codes and regulations change, so does the tech (and subsequent innovation) to make homes safer and installations more efficient, and thus the price will lower over time.
Basically, GFCIs prevent shocks, and AFCIs prevent fires. Both can be installed by a qualified electrician to make your home safer.
Are there any other electrical terms you need defined? Check out our handy page for common electrical lingo.