AFCI Electrical Circuit Breakers

DANA WILSON HOME INSPECTION SERVICES

MASSACHUSETTS

A.F.C.I.

ARC FAULT CIRCUIT INTERRUPTERS

A.F.C.I. HISTORY: The code for 2002 included A.F.C.I. electrical breakers.

 LOCATIONS: All bedroom circuits for new wiring installations. Keep in mind; you have to apply the current code to replacements and upgrades.

UPDATES: By 2008 the areas to be protected were extended to most other rooms of the house.

EXCEPTIONS:  Areas that are required to have G.F.C.Is which are (unfinished basement walls, garages, exterior, kitchens, wet bars, bathrooms and laundry areas) are not required to have A.F.C.Is.

As a home inspector I often find electrical breakers buzzing, in the tripped position and/or I hear complaints like “why do the A.F.C.I. breakers in my house randomly trip” or “when I turn on lights, bathroom fans or an appliance my A.F.C.I. trips”.

Possible Causes for A.F.C.I. Breakers Tripping:

1. Overloaded -- electrical usage has begun to overheat circuit's wires.
2. Short Circuit -- high current resulting from a fault on the circuit.
3. Overheating Breakers -- poor contacts and/or connections at the breaker itself.
4. Ground-Faults -- smaller leakage off of the intended circuit. (Including shock hazards, neutral to ground faults, and the differing current on the neutral wire when it is being shared by another circuit.
5. Arc-Fault -- sparks happening on the circuit or its outlets (lights, receptacles, switches etc…)

Before you can fix a malfunctioning A.F.C.I. breaker or any other breaker for that matter you’ll have to determine if one of the five causes listed above is the problem.

Troubleshooting a malfunctioning A.F.C.I.:

If you can reset the A.F.C.I. breaker and does not trip, it was probably doing its job – protecting against an overload or arc-fault that was only a one-time occurrence.

Next thing is to replace the A.F.C.I. breaker with a new one.

OK, here’s where we get a little more technical. An electrician may temporarily replace the A.F.C.I. breaker with a standard breaker (as part of his trouble shooting methods). If the standard breaker does not trip, then the problem could be a ground-fault as opposed to an arc-fault. If this is the method he chooses, he does not leave your house, he does not leave the breaker in place for any length of time and he replaces the standard breaker with a new A.F.C.I before he leaves your home. However, while the standard breaker is in place he might be able to detect, hear, and/or see signs of something that is causing the breaker to randomly shut off, i.e. arcing; lights that flicker and/or other additional clues that he is trained to look for.

Electricians have devices that can be used to trouble shoot wiring problems. But, the old fashion way of figuring out whats on the particular circuit would be to open all the outlets and junction boxes and check if neutrals have been combined/crossed where they shouldn’t be; typically junction boxes and three way switches where there are two circuits (common scenario in older homes with older wiring and a new A.F.C.I. installed).

During normal use, some appliances have been known to trip an A.F.C.I. Because of the A.F.C.I.s sensitivity to arcing in flat-screen TVs, vacuum cleaners, ground-faults in treadmills and fluorescent lights etc…  The bad news is there might not be anything wrong with any of these appliances or the A.F.C.I. breaker; it might be doing it's job, sensing. 

GOOD LUCK – HOPE YOU FOUND THIS HELPFUL!
www.danawilsonhomeinspectionservices.com 
Dana Wilson, CMI ACI  MA Lic. 761
http://icedamming.blogspot.com/