Bundling M.C

[Big Guns]

What article is bundling MC under, I need to know how many MCs I can bundle together above a ceiling with tie wire. I checked article 310 also installation of MC, I cant find it but Ive seen it before.

 

[Dennis Alwon]

Art. 310.15(B)(2)exception 5

310.15(B)(2) Adjustment Factors.
(a) More Than Three Current-Carrying Conductors in a Raceway or Cable. Where the number of current-carrying conductors in a raceway or cable exceeds three, or where single conductors or multiconductor cables are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.) and are not installed in raceways, the allowable ampacity of each conductor shall be reduced as shown in Table 310.15(B)
Exception No. 5: Adjustment factors shall not apply to Type AC cable or to Type MC cable without an overall outer jacket under the following conditions:
(1) Each cable has not more than three current-carrying conductors.
(2) The conductors are 12 AWG copper.
(3) Not more than 20 current-carrying conductors are bundled, stacked, or supported on ?bridle rings.?

 

[qcroanoke]

What article is bundling MC under, I need to know how many MCs I can bundle together above a ceiling with tie wire. I checked article 310 also installation of MC, I cant find it but Ive seen it before.

330.80 refers you to 310.15
Which would lead me to believe 310.15 (B) (2) is what you are looking for.

^^^ And what Dennis said!

 

[infinity]

Just a note the quote that Dennis posted truncated the last sentence in part (3). It should read

" A 60 percent adjustment factor shall be applied where the current-carrying conductors in these cables that are stacked or bundled longer than 600 mm (24 in.) without maintaining spacing exceeds 20."

This may come in handy if you're not using multi-outlet branch circuits.