Alright, call me late to the party, but ...
A new ad by AFC Cable brought this issue to the forefront: Just what is the difference between AC and MC? Apart from what's printed on the UL lable, that is.
This matters, because there are a few places in the NEC where one is acceptable, while the other is not. For example, if you ever find one of those mythical AFCI devices, and wish to use it in place of an AFCI breaker, you can use AC, but not MC. Health care locations are another such quagmire.
We have had "health care MC" around for a decade now (MC painted green), and Southwire has been marketing their "Simpull" MC (with a bare wire outside the mylar wrap, rather than the usual green wire) for half that time.
Now, it seems, AFC has done away completely with the inner mylar wrapping.
It seems that the 'definitions' I have had in my mind for these two products have been obsolete for some time. MC, contrary to what I thought, need not have a mylar wrapper ... and that bare ground they're putting in some MC pretty much duplicates the bond wire in AC.
Maybe it's time to combine these two sections, consolidate the UL standards, and eliminate the code restrictions on MC?
