I don't see how a lower voltage could cause greater incidence of arcing faults. Most are traced back to bad connections, not failures of the conductors. I am not going to say there is a proven benefit to AFCIs but in theory they do add a level of safety. I also know they were sold to NFPA by Cuttler Hammer with a lot of snake oil. In fact they hit the 99 code, to be implemented the 02 before C/H even had a working model in the market place. After almost 20 years of field experience and development, they do seem to be working as intended. The early ones were dodgy tho. Only one company I know of (SqD) actually recalled marginally performing units and I doubt half of them were actually replaced on the recall although I suspect many more were simply thrown away and replaced with a regular breaker. Some will argue they prevented "X" number of fires but that is like proving a negative. You just have to believe those fires didn't happen and they would have without the AFCI, then let your damage estimates run wild.
