“Exercising” circuit breakers in a residential panel means manually switching them off and then back on, one at a time. Circuit breaker manufacturers and the NFPA recommend exercising circuit breakers once a year. It helps keep the contacts clean and also spreads the internal lubrication around, to ensure that the mechnism will move freely to shut off the circuit when an electrical fault occurs. Exercising does not shorten the lifespan of the breaker. 

    But we recommend that you briefly shut down as many appliances as possible, especially major ones like a clothes dryers or air conditioners, before starting the process. This limits the internal flash at the contact points of the main breaker and dedicated appliance breakers.

    Corrosion and internal dust build-up over time can slow down or lock-up a circuit breaker that isn’t exercised once in a while. Corrosion problems will occur sooner at breakers in an exterior panel with weather exposure. An extreme example of dust contamination is shown below at an older panel (with the dead front removed). The panel was in a wall shared with an air handler closet on the other side, and air had been sucked around the breakers and through the panel into the adjacent return air plenum for years—with a thick line of dust build-up showing at the tiny gaps between breakers.

    Manufacturers and UL also recommend tripping AFCI and GFCI breakers monthly using the small test button on each breaker to verify that they are still functional. We have never met a homeowner that actually does this, but sure there are a few of them are out there somewhere. If you haven’t tested them all year, then your annual exercising of all the breakers in the panel would be a good time to also check the AFCI and GFCI devices.

    When you have not exercised your breakers at all for several years, you may find that some of the older AFCI breakers make a buzzing sound but are stuck and do not trip at first try with the test button. Exercising the breaker with the on/off switch, and then trying the test button again, will often return it to working order.

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Here’s links to a collection of our other blog posts about ELECTRIC PANELS: 

• What causes copper wires to turn green or black in an electric panel?  

• What is the maximum number of circuit breakers allowed in an electric panel?

• When should a corroded or damaged electric panel cabinet or disconnect box be replaced? 

• What is a tandem circuit breaker? 

• When did arc fault circuit interrupter (AFCI) breakers first become required?

• Can an electric panel be located in a closet? 

• Can an electric panel be located in a bathroom? 

• Can you add circuit breakers by different manufacturers to an electric panel if they fit?

• My circuit breaker won't reset. What's wrong?  

• What is a split bus electric panel?

• How do I identify a combination AFCI (CAFCI) circuit breaker? 

• What does a circuit breaker with a yellow or white test button indicate? 

• What is the maximum gap allowed between the front of a recessed electric panel box and the wall surface surrounding it? 

• What are the requirements for NM-cables entering an electric panel box?

• Why is a fuse box/panel an insurance problem for homebuyers? 

• Why is bundled wiring in an electric panel a defect?

• What is the difference between GFCI and AFCI circuit breakers? 

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• What happens when you press the "TEST" button on a circuit breaker in an electric panel?

• What is a Dual Function Circuit Interrupter (DFCI)? 

• What is the difference between a Combination Arc Fault Circuit Interrupter (CAFCI) and an Arc Fault Circuit Interrupter (AFCI) circuit breaker?  

• What is the difference between "grounded" and "grounding" electrical conductors? 

• What does it mean when a wire is "overstripped" at a circuit breaker?

• Why is an old fuse panel dangerous?  

• Who is the manufacturer of those "bad" electric panels?

• Why is the circuit breaker stuck in the middle? 

• What is a double tap at a circuit breaker?

• What is the right electric wire size for a circuit breaker in an electric panel?

• What is the life expectancy of a circuit breaker? 

• Why do some breakers in my electric panel have a "TEST" button on them?

• What is the right size electric panel for a house? 

• What do I need to know about buying a whole house surge protector? 

• What is the maximum allowed height of a circuit breaker (OCPD) above the floor?

• What is the maximum height you can mount an electric panel above the floor? 

• What is the code required clearance in front of an electric panel?

• What is the main bonding jumper and where do it find it in an electric panel? 

   Visit our ELECTRIC PANELS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.