When electricity enters your home, it goes to a circuit breaker box (or fuse box in older homes), where it's divided into a number of circuits. Each circuit is protected by a breaker or fuse. Bedrooms, living rooms and family rooms where only lights, alarm clocks and other small electrical items are usually used are normally onKitchens, laundry rooms, bathrooms and dining rooms—places where you're more likely to use toasters, irons, hair dryers and other big-watt items—are usually served by heavier-duty, 20-ampMajor appliances like 5,000-watt electric water heaters and 10,000-watt electric ranges demand so much electricity that they take their own 30- to 50-amp dedicated circuit (See Fig. D in “Additional Information” below), protected by big, “double The circuit breaker, the wire and even the wire insulation are all designed to work as a system—and that systemTry to push more current through a circuit than it's designed for and things start happening

Wires heat up under the burden of carrying theWhen this happens, the insulation around the wire can degrade or even melt. melts, current is no longer confined within theThat's when fires start. Luckily, the circuit breaker senses the excess current and “trips” to stop the flow of On the night the lights went out at your house, you were fine with only the lights and coffee maker operating.An arc-fault circuit interrupter (AFCI) is a circuit breaker* located in your electrical panel that serves the functions of a normal breaker but also senses hazardous arcing on its circuit and will trip off for this. It can be identified by the special colored test-button near its handle. (Ground-fault breakers also have a button, so read with a magnifying glass to be sure which kind your breaker is.) *A different device is now allowed away from your breaker panel. It resembles the familiar GFCI receptacles. (Its installation is more strict, however.) It is called an "outlet/ branch-circuit type of AFCI" or simply AFCI outlet or AFCI receptacle.

AFCI breakers began to be required by Code in 2002 for new wiring supplying bedrooms. The areas to be protected were expanded in 2008 (where that national Code has been adopted locally) to most rooms of the home. heil heating and ac unitsThe areas left out of the requirement were garage, bathroom, kitchen, and laundry; ac unit popping noisethese were already required to have ground-fault protection for receptacles.how to find seer rating on ac unit It is relevant to AFCI circuit breaker troubleshooting that most AFCIs have a level of ground-fault protection built into them as well. (When this level becomes standardized to meet Code for GFCI protection, such AFCIs will make it possible to meet both AFCI and GFCI codes simultaneously.)

A standard breaker will trip for an overload, a short circuit, or overheating at itself (the first three causes below). To solve their tripping usually involves sorting out which of these three causes is at work. But with an arc-fault breaker, there can be two additional causes to add to the list (the fourth and fifth below): Which of the five causes has tripped an AFCI breaker can be quite important in how you go about solving the problem. Some AFCI brands may have an indicator on them that will show (if you haven't already reset!) whether the cause of the last trip was an arc-fault or not. But you will still need to know what to fix and where. The table below also shows some additional causes having to do with the breaker itself or with long-standing things about the wiring in the house.Text from this point on may have disappeared (just as the whole website could some day), but you can download the whole website for offline use (with no disappearing text) for $10. A F C I    S Y M P T O M

Trips within 5 sec. Trips in 1 min. to 1 month Trips when any small load runs on the circuit Trips when some-thing runs on another circuit Never trips, even when "TEST" is pushed Reduce wattage in use on circuit Replace AFCI and put in diff. location in panel (4) Neutral shared with another circuit AFCI's own white goes to neutral bar, circuit white to "load neut" NOTES to narrow down which cause: 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 often a ground-fault, less often 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 ["(4)" above].

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. Although I have never yet been called to find the location of an actual arc that was tripping an AFCI, here is what could be done. As long as you do not leave it in place beyond your time of vigilant searching, 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. I am comfortable suggesting what might sound like playing with fire, because few cases of arcing are ever able to start fires. In most homes (most don't have AFCIs), when arcing at connection points ("series" arcing) has been happening for a while, it does commonly show itself eventually as a partial outage of the circuit, from the arcing point on.

This can then be troubleshot more easily. Some appliance models, during their normal operation, have been known to trip an AFCI, by its sensitivity to either arcing (in flat-screen TV, vacuum, other motor) or to ground-faults (in treadmill, fluorescent lights). There may not be anything wrong with the appliance or breaker, unfortunately. If the AFCI breaker lets you reset it and does not repeat its tripping, you do not need to know or to worry about the cause. For the record, it was probably an overload or arc-fault that was only a one-time event. By the 2014 Code anyone (including homeowners) replacing a receptacle in most rooms of a house will be required to make it be arc-fault protected. This will have to be accomplished by installing a costly device there or earlier in the circuit. No more "if it's broken, just replace it." "I'm a retired police Lieutenant so writing a note to a detective is familiar to me. What wasn't familiar, (because I just found your site and bought your e-book), was how to troubleshoot an AFCI!