I just replaced four 15 amp breakers to our bedrooms with new Arc Fault style units. Three of them are perfect. The fourth keeps tripping. The circuit goes to 6 outlets, 1 in one room, 5 in another. I was wondering if there is an easy way to solve what is going on. I plan to disconnect the white wire at the panel breaker and go to each outlet and try to figure which one is causing the problem. I did replace the breaker with a standard one and all appears OK. I am guessing that the neutral, white, and the ground are connected /touching somewhere. That's why it is OK with the regular breaker but not with the AFC breaker.
Thanks

 

Your home was misswired like mine and a couple of circuits shared the neutral somewhere. In my case, it was with a lighting circuit with 3-way switches. Does your AFCI trip when other circuits are OFF?

 

That would be my guess as well. AFCI breakers also have GFPE protection as well. This is what normally causes the tripping when an equipment grounding conductor and the grounded conductor touch. The tripping current for GFPE protection is normally around 30 milliamps.

Chris

 

There are only outlets on the circuit. I did notice that when I turned on an overhead light, the breaker tripped. My guess is that there is a neutral tied to another circuit neutral. When the other circuit is turned on, this problem circuit trips. I am not sure why the circuit that is being activated does not trip also. I guess that I have to take it wire by wire to try to isolated the problem.

 

First try the problem circuit with one of the known good AFCI breakers. It is not that rare to find an AFCI breaker that is broken brand-new out of box.

 

I had already tried a different breaker with no luck. The first outlet in the string had two small indentations in the white wire. It is a metal box in a plastered wall. The nick appeared to be almost thru the insulation but not a clean cut. I used electrical tape and repositioned the wire for a better fit in the box. All OK.
I sure do believe in the arc fault breaker. If that had been on the hot side with a regular breaker, there could have been problems just waiting to happen.
Thanks to all who shared their opinions on this matter.