1)What is the proper way to wire for AFCI? It says it cannot have shared neutral, otherwise, it will trip the AFCI. What do they mean by shared neutral? Does that mean we cannot have a 12/3 use and must wire with a 12/2 instead? Can we wire a 12/2 with lights & receptacles under same AFCI circuit? Will AFCI work? What happend to old panel box that was installed years ago? I don't think they have dedicated neutral? How will AFCI work in those panels?
2) Is it a violation to wire lights, smoke detector & receptacles under the same circuit, assuming the load is sufficient?
the AFCI won't work on a multimire branch circuit, such as a 12/3 run to the attic to feed a couple of bedrooms, etc. It senses the imbalance between the ungrounded and the nuetral. If you are using existing circuits, why are you arc faulting ?Are you bringing something up to current code? If you run new circuits, the AFCI will work fine for lights and receps. as long as it is a 2 wire cicuit. Nothing comes to mind about the smoke being on it's own, but there maybe a stipulation for it in the Firm Alarm code.the code section on AFCI also says all Outlets in the room. def. of an outlet is: a point on the wiring system at which current is taken to supply utlization equipment. sounds to me like they want everything in the room arc faulted.
Couple of comments: They now make AFCI circuit breakers suitable for use on multiwire branch circuits. Another comment would be why would one use #12 awg for wiring a bedrom? I don't think anyone should be concerned about putting anything on an AFCI protected circuit. If I have an arcing condition that an AFCI can detect, I want to know about it and have the breaker trip :-)
George, good info on the multiwire AFCI. Haven't seen one yet. Isn't that why they developed AFCI technology, to detect arcing faults that a breaker would not? I personally use #12 AWG for everything, lights and receps in a house.