I don't know how they can say there is no such thing as a series arc.
The information does not pertain to the short arc that occurs when a circuit is broken. An series arc cannot be sustained at normal dwelling unit voltages. The poor connection of high resistance fault or glowing connection is not really a series arc as it is not an arcing fault. It is just a high resistance point where high heat is produced by the flow of current. The resistance limits the current to a point far below the trip point of the OCPD. I think that the AFCI people went to great lengths to prove that there are no sustainable series arcs at dwelling unit voltages because most were calling the high resistance connection a series arc and they know that their device cannot directly detect such a fault.
Don
