Fix a Sensitive Arc Fault Circuit Breaker

How to diagnose and fix an arc fault circuit interrupter (AFCI) problem.

Most of the time you can find the cause of nuisance tripping of an arc fault circuit interrupter (AFCI) and correct the problem without calling an electrician.

By the DIY experts of The Family Handyman Magazine

Solve an AFCI tripping problem

If you have a problem with an AFCI (arc fault circuit interrupter) shutting off in you main electrical panel, you’re not alone. Arc fault circuit interrupters are prone to “nuisance tripping,” which is probably what you’re experiencing. AFCIs are designed to sense an arc, which is an electrical “leak” caused when a hot wire touches a neutral or ground but doesn’t trigger the circuit breaker. Although current-sensing circuitry enables AFCIs to detect arcing conditions, unintended trickles of current may also cause the breaker to shut off (AFCIs are very sensitive!).

To solve the nuisance tripping problem, start with things you can do yourself. Unplug or turn off surge protectors plugged into bedroom outlets, fluorescent lights with electronic ballasts, and lighting controls with LED displays that are on the AFCI circuit. They sometimes allow current “leakage” that can trip the AFCI. Damage or deterioration to wires or cords (which can happen when furniture is pushed against plugs in an outlet) also causes arcing faults and will trip the circuit. If you identify one of these sources, you’ll have to replace the electrical item.

If unplugging electrical and electronic devices doesn’t solve the problem, hire an electrician to install a new AFCI breaker in the electrical panel. There’s no reliable method for testing AFCIs (the test button isn’t always accurate). If the nuisance tripping stops, then the old one was probably defective.

If the breaker still trips, the electrician then needs to track down the cause by going into each switch, receptacle and light box to look for a wiring problem. Wires are often folded (jammed) into boxes quickly, and if the wrong two wires make contact, they can trip an AFCI.

The National Electrical Code required AFCIs for receptacle outlets in bedrooms beginning Jan. 1, 2002 (local jurisdictions may have additional requirements). Don’t confuse AFCIs with ground fault circuit interrupters (GFCIs), which are designed to protect against shocks (not arcs).

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