Is it necessary to convert to THHN, and if so why?

[Molo]

The question is about adapting from 12-2 MC cable to 800 series Legrand plastic wiremold and if we have to use THHN in the wiremold, and if so why?
-This will be done in the attic where the wiremold will be run into from the living space below.
-Legrand makes an adapter for this, but 3 wirenuts don't fit and we don't want to use wagos or similar.
-We considered using wiremold boxes mounted in the attic.

Question: can we strip the mc cable and leave enough wire to run into the wiremold until the first box? The mc cable would be connected to the adapter, but this would prevent us from having to convert to THHN.

https://www.legrand.us/wire-and-cab...metallic/400-800-entrance-end-fitting/p/810a2

Thank you

 

[wwhitney]

Typically the wires inside MC cable have their type printed on them (and that may be THHN). As long as the insulation on the individual wires is labeled with one of the recognized NEC types, you can transition from MC cable to wiremold without splicing, by stripping off enough of the MC armor to provide the length of individual conductors you require to reach the next box.

Cheers, Wayne

 

[Sponsor]

 

[Molo]

Typically the wires inside MC cable have their type printed on them (and that may be THHN). As long as the insulation on the individual wires is labeled with one of the recognized NEC types, you can transition from MC cable to wiremold without splicing, by stripping off enough of the MC armor to provide the length of individual conductors you require to reach the next box.

Cheers, Wayne

Thank you. Is the wire on the inside of MC cable different than THHN? If so, how is it different other than the label? I'm trying to determine if they act differently in wiremold...