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We had a whole-house remodel done a couple of years ago with all new wiring and a new sub panel stuffed with AFCI breakers. This was all done by a (supposedly) competent licensed electrician.

We've had more than a few of these breakers trip in the time we've been in the house, always indicating an "Arc" fault. Two frequently-used circuits in particular - one circuit servicing our kitchen island (one available outlet, a built-in microwave and a beverage cooler), the other circuit servicing various kitchen outlets - have been constant problems. Using the microwave frequently causes the breaker for that circuit to trip, and If my wife uses her mixer in her baking center on "high" that inevitably causes that breaker to trip. I've replaced both breakers with new ones, but that hasn't improved the situation. Since the microwave was an older one that we salvaged from the old house, I replaced it with a brand-new model and that too hasn't helped either.

What I'd like to do is to replace the breakers for those two circuits with CFCI breakers. These breakers have a "pigtail" to be attached to the neutral buss, the same as the AFCI breakers they'd be replacing. I know that setup isn't "code" in our area but the real question is "would this work OK?"
 

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Before you do that it would help to check the connections on the circuit. An arc could be as simply as a loose connection.
 

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Although AFCI breakers are becoming required in more and more types of residential circuits they are notorious for nuiscance tripping. Some people say the new ones are less prone to it but I don't buy that. There is also limited evidence that AFCIs actually reliably provide the arc fault protection that they claim to.

Most electricians hate them too, but are compelled to install them or else put their license and career in jeopardy. You can't blame the electrician for following the code.

As long as you are the property owner and understand the liabilities associated with introducing such a code violation into your own panel I would say just replace them with straight GFCI. Keep the AFCI breakers on a shelf and put them back if you decide to sell the home.
 

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I agree with Jim. Check for loose connections.

Also, not quite sure your reasoning for replacing AFCI breakers with GFCI breakers. These provide two totally different types of protection to the circuit.

If the AFCI breakers are tripping they are trying to tell you something.

AFCI = Arc Fault Circuit Interrupter
GFCI = Ground Fault Circuit Interrupter

The circuit servicing one receptacle, the microwave and the drink cooler may be tripping due to the appliances pulling more power than the circuit can handle. If the microwave is running and the drink cooler compressor kicks on it may be tripping the breaker because the circuit is overloaded. So if the breaker is a gFCI or AFCi it will still trip in this case.

You may want to watch what appliances you use at the same time which are on the same circuit to prevent an overload on that circuit.

But being they are AFCI breakers they should tell you what is causing them to trip. Most have some type of indicator light on them. The LED on the breaker should flash or light up indicating the cause for the trip.

As far as the circuit with the mixer what other appliances are on that circuit that may be running at the same time. Again, it may be a circuit overload.

Whether it results are a circuit overload or Arc Fault (given the breakers are not faulty) changing one AFCI breaker for another or a GFCI will not solve your issue. Another AFCI breaker will also trip and if it is an arc fault putting in a GFCI breaker instead is not going to solve your arcing problem.

Your microwave may be too old which is causing the breaker to trip. It may be time for a new microwave. I had the same problem with a microwave of mine. I even had it on a dedicated 20amp circuit and it still tripped here and there until I replaced it. It has not tripped in the two years since I replaced it.
 

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Just replace all your breakers 2 at a time to 60A breakers. Just change 'em all to 60A plain breakers. They'll never trip!

Why don't you do that? Because you understand why that would be dangerous. You don't understand AFCIs, so it makes sense to you to rip em out. See the fallacy? "what is safe" isn't decided by "what you know". Facts don't care what you think they are.

AFCIs detect arc faults, or wire arcing. They were originally required for bedrooms to protect electric blankets. But the science showed that what actually happened is they detected faulty wiring in the walls that was arcing and starting a fire. Thus, Code widened the requirements to high-use circuits likely to have that problem. (but not on circuits which required GFCI also, because there were supply issues with GFCI+AFCI combo devices).

There are 5 kinds of arc faults. 3 of them, "parallel arc faults", are limited shorts between 2 of the 3 wires (hot, neutral, ground) which for some reason aren't extreme enough to trip the breaker. The other 2, "series arc faults", are a hot or neutral wire having a loose connection causing arcing. Current is limited by the load, so it will never trip a plain breaker or GFCI. Any of these can set a junction box on fire.

How do AFCIs detect them?

  • Hot-ground and neutral-ground parallel arc faults also happen to be ground faults. So any arc-fault breaker that requires the neutral wire, uses a "weak GFCI" to look for differences in hot-neutral current. This type of trip is troubleshot just like a GFCI trip. You are looking for leaks to ground, often via faulty appliances.
  • Hot-neutral parallel arc faults, and series arc faults, are more complicated. For this, the AFCI uses a Digital Signal Processor to look for certain waveforms - it "sounds like" that crinkle-crunch sound you know if you've ever plugged in headphones into a flaky socket, or hooked up stereo speakers with the power on. That is due to loose wires or rarely, hot and neutral getting just close enough to short "a little".

Most modern breakers can give you a readout of which thing exactly they are tripping on and that's rather useful for troubleshooting. For instance Eaton BRAFGF breakers have 7 report codes which narrow it down pretty well.

Square D's newest breakers (white and purple button) use a thing called "Time Saver Diagnostics" (go ogle that if relevant).

See if your model of breaker has this kind of code.


You might try an Eaton BRAFGF for testing but it should certainly not be left permanently in a non-BR panel. The bus stabs are not the right shape, and it can cause (one guess) arcing. Eventually they'll move that innovation into the Eaton CL line; those are legal in GE, Siemens and HOM, Crouse Hinds etc.
 

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The early ones were problematic. I had tons of nuisance trips with the original MOD1 GE AFCIs. I replaced them with the later MOD3 (that's a GE term by the way) and the nuisance tripping went away.
 
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