We have three bedrooms which are on 3 arc fault breakers (home built in 2007). For the past couple of months, two of these three breakers have been tripping when there's a slight load on OTHER circuit. A hair dryer in the kitchen, washing machine running a load, oven preheating.

The oven control board actually did go out. But twice, the oven was heating up or in the process of cooking, and a bedroom arc fault breaker tripped. Oven went out, and we saw it happening when using a hair dryer in the kitchen. We can't reproduce it, as it's only happened a handful of times over the past two months.

An older master electrician came out this morning and said that nothing was loose in the breaker boxes and we'd have to go to each receptacle and connection in those circuits because it's likely a loose wire causing the trips. Does that make sense? Would that be the case for two rooms at the same time? Could our oven control board going out have caused the initial problems and now it's a loose wire? I don't really know which direction to go now.

By the way, the electrician was super nice and didn't charge me a dime since he couldn't do much.

If the odd symptoms of problems on other circuits are affecting separate AFCI breakers, and there is no apparent normal reason for the AFCI to trip, the reason can be one of several odd, abnormal reasons.

I know that does not help much. If all is wired correctly, a problem on any circuit cannot cause a CB to trip on another circuit.

There must be some miswire, improper grounding at the panel or in any circuit, criss-crossed wiring, the possibilities are numerous.

What are your capabilities? This can be a long tedious task to check connections as the electrician suggested, or go through the entire system looking for a needle in the haystack.

Well, I DO know that I cannot pay an electrician to sit at my house for 2 or 3 days looking for loose wires. :) I'm not completely ignorant, but I'm not afraid to give anything a shot. I know when to draw the line, but I think I'm perfectly capable of checking all my 110v receptacles for loose wires. Sounds like I just need to check all the grounds and neutrals for tight connectivity? I just went around with the notorious blow dryer trying to recreate it and trying to map out my circuit. I also verified the dryer wasn't on the same circuit as the bedroom when the last trip happened. How can I determine if they're sharing a common neutral? Is that even the next step? Thanks in advance for the help.

I understand. I charge $65.00 per hour, adds up quickly. Largest reason I choose to not do residential work. Even thou my tech's are excellent, some problems can be difficult to find.

That was one issue I meant to mention, shared (common) neutrals, that can be the source of problems if loose or mis-wired. The one that needs to be considered is the neutral from the utility, the service drop from a utility pole to a home and through the meter to the panelboard. Often times the connection at the pole or the service riser can be loose, but the symptoms are not the same as yours, lights thruout the home can dim and get bright. This condition can cause higher than normal voltages be impressed on lights, causing burnouts, and burn out appliances.

Homes are often wired with several circuits that share a neutral. This is determined by looking in the panel for cables with black, red, and white wires, and the black and red on separate single pole breakers. These two 120 volt circuits share a neutral.

Single pole AFCI breakers do not work with shared neutrals.

Other circuits that are intended to be separate circuits that cause AFCI breakers to trip indicate a mis-wire somewhere in the wiring or at the panel.

You can check the connections at all the receptacles, but not just the neutrals and grounds, need to check the live wire also.

Neutrals and grounds cannot connect anywhere in the wiring, only at the Main Panel that contains the Main Breaker. If the Main Breaker is outside at the meter, the Main Panel will, or should, have two terminal strips, one for the white neutrals, which will be insulated and isolated from ground wires, and a separate terminal strip, (we call them bars, neutral and ground bars) only for bare or green equipment grounds.

The grounding of the service is easy but can be easily done incorrectly.

I need to provide the obvious caution, that working on a panelboard must be done with the power off,if the Main Breaker is in that panel there is still two live conductors and terminals at the Main Breaker that is a danger. Safety codes do not allow electricians to work of live equipment unless suited with the proper protective gear. To suit up one man costs about $1000.00. So I do not know how you plan to work on your panel safely. Even opening a live panel just to look requires being suited up.

You can shut off circuit breakers to work on circuit wiring and opening devices. Best to trace the problem circuit from panel to the end looking for every junction box and splice point to be sure there are no mis-wire or criss-crossed wiring.

You may find a junction box with several circuits that may have loose or burned splices that are shorting out each other.

As I mentioned, your having some odd symptoms, therefore the problem is not typical, or something I can pinpoint.

Let us know who you make out.

Our main panel has three 2-pole breakers: Main, Range, A/C. It doesn't have the bars you mention that it should. Those are located at the indoor panel off that Main breaker. He checked all connections on the main panel for tightness and also said that is IS NOT an arc fault issue or bad breakers.

If I remember correctly, the first few times it happened, the A/C was turning off. I'm pretty sure when the unit kicked off was when the first two episodes happened where one of the AFCI's tripped. Have they just become more sensitive over time? Doesn't that cause a voltage drop throughout the house like when lights dim when A/C kicks on (ours don't dim). Would that point to a bad breaker? Why would two AFCI's go out at the same time? That's why I'm defending the "bad breaker" solution. Don't they have 10-year warranties?

I purchased a receptacle tester and have checked most receptacles in the home already and it checks out fine so far. I was even told by the local electrician to wiggle the tester around in the outlet and see if an AFCI trips. That would identify a loose connecter in that circuit. I'm out of ideas, so I guess I'll go back to trying to reproduce the problem...