AFCI clarification in 2011 NEC

[titan1021]

Just looking for some clarification on NEC 210.12 (B) Branch Circuit Extensions or Modifications-Dwelling Units

(2) A listed outlet branch-circuit type AFCI located at the first receptacle outlet of the existing branch circuit.

Does the above have to be installed utilizing the method described in 210.12 (A) - Exception No. 1 or can it just be installed at the first receptacle regardless of the existing construction type.

It seems unreasonable to expect someone to install conduit and metal boxes to accommodate an AFCI receptacle in existing construction, yet it wouldn't surprise me given other silly things that are called for throughout the code.

Thanks.

 

[luckylerado]

IMO for modifications of an existing circuit, at the first receptacle regardless of the existing construction type meets the requirement.

Not for a new branch circuit.

 

[jumper]

406.4(D)(4) allows replacement with no mention of existing wiring method.

 

[titan1021]

Thanks for input guys.