Originally Posted by jas1999
Any ideas on what the issue could be?
According to a knowledgeable electrical inspector, teacher on the subject and consultant on the subject, "...there is convincing evidence that an AFCI tripping simply indicates that a ground fault or arc-fault exists and that the AFCI is doing its job." You can read the article here
. There is much more on the subject on Mike Holt's site if you are interested. Here
is a link to a Square D document on how to troubleshoot.
AFCIs trip on very specific circumstances indicative of an arc fault under the control of a microprocessor monitoring the line. They will trip on problems which will go unnoticed with a standard breaker. The also have a GFCI function built in. The problem causing the tripping could be a arc fault or a ground fault. Wiring problems are not unheard of in new houses. It is also possible the problem is in the equipment. That said, there does seem to be the odd case of nuisance tripping here and there.
Some people choose to treat the symptom by replacing the AFCI with a standard breaker. Hopefully it does not come back to bite them. It is also likely a violation of code because AFCIs are typically not installed unless required by code. Some people chose to diagnose the problem properly and treat the cause. Unfortunately, many electricians don't seem to be too good at doing this.
FWIW I have AFCIs in my house and have never had a nuisance trip.