AFCI vs GFCI

There are two main types of safety devices that inspectors look for: Arc-Fault Circuit Interrupters (AFCIs) and Ground Fault Circuit Interrupters (GFCIs). Both provide different types of protection: the AFCI generally protects against fire and the GFCI against electrocution.

Arc Fault Circuit Interrupters
AFCIs work by continuously monitoring the electrical waveform and promptly interrupting the circuit if a wave pattern that is characteristic of a dangerous arc that can cause a fire. The best way to think about them is like they are small lightning bolts. Much like lightning, arcs create a large amount of heat that can ignite a fire behind the walls of a home. 

AFCIs can be found in both the receptacles on the wall and inside the electrical panel. They can usually be identified with either the term “AFCI” written on them or by a white curly wire in the panel. Starting in 2002, bedrooms were required to have AFCI protection, and it has been expanded multiple times to include most electrical circuits. There are several exceptions that any licensed electrical contractor is aware of (such as bathrooms), and I won’t bore you with quoting the long and confusing Canadian Electric Code. Bottom line is that AFCIs are expensive but serve a valuable role in preventing electrical fires.  

Ground Fault Circuit Interrupters
GFCIs can look very similar to AFCIs (and to make it more confusing it is possible to have GFCI AND AFCI protection in the same area) but serve a different purpose. A GFCI looks for differences in current between the hot and neutral conductors. What exactly does that mean? If the current in the neutral is lower than the hot, it means electricity is travelling where it should not be going. Often this means it is passing through a human body. A GFCI detects this almost instantly and stops the circuit, potentially saving a life.

The language surrounding where GFCIs are required is confusing but the simplest way to look at it is that any electrical outlets within 5-6 feet of a water source need GFCI protection. Water and electricity do not mix, and the combination can be fatal without the safety of a GFCI.

An Important Note
Home inspectors are not electricians or code compliance officers. While I have a working knowledge of electrical codes, I do not cite current codes in my reports. There are two reasons for this:

• Code requirements are constantly changing.
• New requirements are usually NOT retroactive.

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In other words, if the home predated AFCI and GFCI requirements you do not have to add them to be code compliant unless you perform major renovations. Having said all that, my focus is on safety, and regardless of what the codebooks say dangerous electrical currents do not care when your home was built. Therefore, I always recommend upgrading your electrical system to the latest safety requirements for you and your family’s protection. These two devices serve different purposes, but both are valuable safety features that should not be ignored.