Then UL revised the AFCI standard and the NEC is requiring the use of combination AFCIs for no reason???????????????? There is no technical justification for these changes??????????????
Don, The UL standard has not been revised. There are several different types of AFCIs and they have separate listings (I am sure that it will be quite confusing).
I posted the following in the MH forum:
Panel 2 has accepted the requirement to put AFCI protection for all 15 and 20 ampere circuits in a panelboard whenever it is replaced in an existing home. It has not accepted the requirement to put AFCI protection for all 15 and 20 ampere circuits in a new home.
The vote in the panel was indecisive in that there were a couple of abstentions and 2/3 of the members were not achieved. At this point, it is unknown whether or not the above requirements will get the 2/3 vote required to make it into the Code. If it does, it will require a higher level of protection for a one month old home if a panelboard is replaced or added than it will for a new home.
In addition, the AFCI protection will have to go to the "combination type" in 2008. The combination type will detect series faults. For what it is worth, the parallel faults have to exceed 75 amperes for the present AFCI breakers to "see" the fault and open the circuit.
