MWBC & AFCI?

[MannyBurgos]

has anyone had success with a multiwire branch circuit and afci of the receptacle type without isolating grounded conductors? One of my local jurisdictions just adopted 2011 and now requires cafci pretty much everywhere except kitchens, baths, etc. most of the houses down by me are pretty much wired with nm and bx. A lot of cloth wiring as well. I see this as a big problem for houses having the old cloth wiring. I want to know what are my options when we start replacing receptacles and service equipment. What do you all think?

 

[Ponchik]

It depends on the jurisdiction. Ask you AHJ to see if they will require AFCI when you do device change, when you do service change/upgrades or when you do circuit extensions. I know when you install a new circuit it HAS be AFCI protected (some exceptions do apply depending which code cycle you are on)

Otherwise AFCI are not a problem on the line side of the receptacle.

 

[GoldDigger]

Just as a two pole GFCI with a single neutral wire can be used with an MWBC, so a two pole AFCI can feed an MWBC without false tripping if the GF component of the breaker.

 

[MannyBurgos]

Thanks for the reply's. I understand that a 2 pole afci breaker will solve many of the mwbc problems but was wondering if anyone had any luck with the afci receptacle types used as a feed through device on mwbc's?