iwire,
The fail safe is because these are electronic devices that will fail just like the GFCIs do. Yes, I know that both AFCIs and GFCIs require monthly testing. How many homeowners do this?? If the AFCI doesn't test ok, how many will put a new AFCI in?? The GFCI study that resulted in the new GFCIs that won't reset if the electronics have failed showed that in areas that have lightning up to 58% of the GFCIs are providing no protection.
As far as the cost benefit, Fred covered that well. We will never be able to afford or even want all of the safety devices that can be made. You could make collision proof cars with auto pilot and radar collision avoidance systems. This could save many many lives, but would cost millions per car. I don't know what cost is acceptable, that is why I'd like the government to do a cost benefit study like would be required if this was a federal rule.
Don
