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What is the average life expectancy of an AFCI or CAFCI circuit breaker?
Wednesday, December 11, 2019
How long does an AFCI breaker last?
An AFCI or CAFCI circuit breaker should last 30 to 40 years, with an average of 35 years. The only exception to this average lifespan is AFCI (Arc Fault Circuit Interrupter) breakers that were manufactured previous to 2008, when they were superseded by the code requirement for new CAFCI (Combination Arc Fault Circuit Interrupter) breaker. Our experience is the that older-style AFCI breaker had about a 12% failure rate, when tested with the test button, at less than 10 years. Not sure why. The Eaton CAFCI breaker shown above had already replaced one of the original AFCI breakers in the panel of a 2006 home when we inspected in it in 2015.
Because a breaker is a mechanical device, a humid outdoor location or the corrosive atmosphere of a room where pool chemicals are stored, for example, will shorten the lifespan. And, conversely, an indoor and dry location with only modest temperature variations will extend it. Also, frequent tripping due to repeated overcurrent or arc fault events will hasten failure.
The primary purpose of a circuit breaker is to protect your home from a fire caused by overheating of the wires because of too much current flowing through them. When the current flow exceeds its marked amperage rating, the breaker is supposed to trip, cutting off the electricity to the problem circuit. An AFCI or CAFCI breaker serves a dual purpose: it also trips when it recognizes any arcing or sparking in the wires due to fraying or other damage.
A malfunctioning breaker fails by doing nothing—NOT cutting off the electricity. There is no outward indication that anything is wrong until wire insulation starts melting and you smell smoke.
AFCI and CAFCI breakers have not been around long enough to warrant replacing them based on age, but the manufacturers recommend testing them with the test button monthly. If you think that a little obsessive/compulsive, maybe a couple of times a year would suffice.
The breaker switch itself should be “exercised” once a year by flipping each breaker on and off three times. Because appliances with compressor motors can be harmed by repeated power interruptions, you should first shut off or unplug any freezers, refrigerators or air conditioners in the home before using the test buttons or exercising the breaker switches.
Here’s a graph comparing the life expectancy of an AFCI breaker to other electrical components in a home.
Go to our blog post What is the average lifespan of the parts of a house? for rating of other house components. To understand the basis, potential use, and limitations of lifespan ratings, see our blog post How accurate are the average life expectancy ratings of home components? Are they actually useful?
Also, see our blog posts What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker? and When did arc fault circuit interrupter (AFCI) breakers first become required?
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Field Guide for Home Inspectors, a quick reference for finding the age of 154 brands of HVAC systems, water heaters, and electrical panels, plus 210 code standards for site-built and manufactured homes, and the life expectancy rating of 195 home components. Available at amazon.com for $19.95.
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Here’s links to a collection of our other blog posts about AFCI and GFCI RECEPTACLES AND CIRCUIT BREAKERS:
NOTE: These life expectancies are based on data provided by InterNACHI, NAHB, FannieMae, and our own professional experience. Because of the numerous variables that can affect a lifespan, they should be used as rough guidelines only, and not relied upon as a warranty or guarantee of future performance.
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