Notice the AFCI device must also be installed in a box with only two 2-wire cables.
When I read these Eaton TRAFCI-15 Installation Instructions, the first thing that sticks out to me is, under
3. Should you install it?, at the very last bullet point is the quote, "If you do not fully understand these instructions, you should
seek the assistance of a qualified electrician." This sheet is a generalized instruction, and the inference is that a qualified electrician knows more than contained within this document. Therefore, it is not the COMPLETE instruction. (Thanks M.D. for jogging my brain.
)
Along this same line, the second image below in
6. Identify cable / wires says to contact a "qualified electrician" when there are
more than two wires (not including the grounding wire)
And, most importantly, at the very beginning of this Installation document is the "CAUTION! Must be installed in accordance with national and local electrical codes."
And in this lower right box, just above, titled
Placement in circuit I note that "
circuit", as well as "
branch" are not defined in NEC Article 100 Definitions. Therefore, I think it is a mistake to read "The OBC Type AFCI must be placed as the first outlet in the
circuit. Always place OBC Type AFCI in postistion [sic.] A. All outlets of the protected
branch, including lighting and receptacle outlets, must be connected to the load side of the AFCI," as "The OBC AFCI must be the
first outlet of the branch circuit."