Are you having trouble with the arc-fault circuit interrupters (AFCI) shutting off in your main electrical panel? AFCIs are prone to “nuisance tripping”. They’re designed to sense an arc, which is an electrical “leak” caused when a hot wire touches a neutral or ground wire, but doesn’t trigger the circuit breaker.
Causes for the electrical interruption may include:
- An overload–when electrical usage would have begun to overheat a circuit’s wires.
- A short circuit–very high current resulting from a fault on the circuit.
- An overheating breaker– when the breaker itself has poor contacts or connections.
- A ground-fault–smaller leakage off of the intended circuit. In this I include shock hazards, neutral to ground faults, and the differing current on the neutral wire when it is being shared by another circuit.
- An arc-fault–sparking happening on the circuit or its lights or appliances.
Most of the time you can find the cause and correct the problem without having to call an electrician.
Tips for troubleshooting an arc-fault interrupter
- Don’t confuse AFCIs with ground-fault circuit interrupters (GFCIs), which are designed to protect against shocks (not arcs). To tell whether immediate tripping is from a ground-fault versus a short circuit, you might have to temporarily replace the AFCI breaker with a standard breaker (putting the solid white wire from the AFCI’s terminal into the panel’s neutral/ground bar). If the standard breaker holds, then the problem is more likely to be a ground-fault than an arc-fault.
- In the case of an arc-fault device introduced into an existing home, a common cause of tripping will be that the neutral of the circuit is mixed somewhere with the neutral of another circuit. The two common places this mixing of neutrals would occur are at a 2-gang or 3-gang switch box where both circuits are present, or in a 3-way switch system where the neutral for the light(s) has been borrowed (improperly) from the other circuit.
- As long as you do not leave it in place beyond your troubleshooting, a standard breaker could be put in the panel in place of the AFCI. You might then be able to hear, see, or smell signs of heat or arcing. Blinking lights on the circuit would give additional clues.
- In most homes (most don’t have AFCIs), when arcing at connection points has been happening for a while, it commonly shows itself as a partial outage of the circuit, from the arcing point on.
- Some appliance models have been known to trip an AFCI by their sensitivity to either arcing (in flat-screen TVs, vacuums, other appliances with motors) or to ground-faults (in treadmill, fluorescent lights).
- If this doesn’t solve the problem, hire an electrician to install a new arc-fault breaker in the electrical panel. If the nuisance tripping stops, then the old arc-fault breaker was probably defective.
- If the arc-fault 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.
According to 2014 code, anyone, including homeowners, replacing a receptacle in most rooms of a house will be required to make it arc-fault protected.
Need to call an electrician?
If your arc-fault circuit interruption is not responding to your troubleshooting efforts and it’s time to call an electrician, contact Roberts Electric. Our residential team is skilled at troubleshooting and fixing electrical problems.