MTW as a ch3 wiring method

[Todd0x1]

310.10 Uses Permitted. The conductors described in 310.104
shall be permitted for use in any of the wiring methods covered
in Chapter 3 and as specified in their respective tables or as
permitted elsewhere in this Code.

MTW has the application provision of Machine tool wiring in 310.104.

310.10 is a little confusing. Does covered in ch3 AND as specified in tables mean you can only use it per its applicaiton provisions? Or is it the other way around and you can use any of the 310.104 conductors in any ch3 application?

 

[hbiss]

MTW is THWN with added oil resistance. Many types of conductors are dual rated MTW.

you can use any of the 310.104 conductors in any ch3 application?

Generally yes.

-Hal

 

[winnie]

310.10 is a little confusing. Does covered in ch3 AND as specified in tables mean you can only use it per its applicaiton provisions? Or is it the other way around and you can use any of the 310.104 conductors in any ch3 application?

My understanding is that you can only use conductors per their application provisions, but as @hbiss points out many conductors bear multiple ratings, and you can use whichever rating applies.

If you had wire that was only rated MTW, then IMHO it could only be used for machine tool wiring.

-Jon

 

[petersonra]

Mtw is allowed by UL to be used in virtually any of the special programs they have set up for custom and semi custom items such as mcc, switchboards, and control panels, to name just a few. It is usually also rated as awm.

It is more like tew than thwn.