Mustang125
Member
- Location
- New Hampshire
I understand you can't bundle more than 5 MC together. But I can't find if you are allowed to bundle your fire alarm MC with your regular circuits?
Using 12/4 MC copper and 3 CCC's per cable, the cap would be 6. With 4 CCC's per cable, i.e. where the neutral is counted as a CCC, the cap would be 5 cables "bundled" together. There's your magic number.(4) Adjustment factors shall not apply to Type AC cable
or to Type MC cable under the following conditions:
a. The cables do not have an overall outer jacket.
b. Each cable has not more than three current-carrying
conductors.
c. The conductors are 12 AWG copper.
d. Not more than 20 current-carrying conductors are
installed without maintaining spacing, are stacked, or are
supported on “bridle rings.”
Your kidding? Haha wow, I have been with my company for 8 years now and we have about 40 guys, and every single person and job I have been to we have never tiewraped more than 5 MCs together, beside derating can you think of a reason? Maybe 5 is the amount before you have to derate? If I remember right, an inspector even made us go above the ceiling in an existing space where all the MCs where entering the electric room, and separate them into groups of 5 or 6 I think.... haha. But don't you have to start derating after 4 current carrying, so 2 MCs together would have to be derated?
I understand you can't bundle more than 5 MC together. But I can't find if you are allowed to bundle your fire alarm MC with your regular circuits?
Thanks for all the info guys. So basically, you could bundle 10- 12/2 MCs together without derating?
Depends on the total number of current-carrying conductors (20)... not the number of cables. I'd say someone made a generalization, to make a visual inspection easier in the field, to cover 310.15(B)(3)(a)(4).
Using 12/4 MC copper and 3 CCC's per cable, the cap would be 6. With 4 CCC's per cable, i.e. where the neutral is counted as a CCC, the cap would be 5 cables "bundled" together. There's your magic number.
Thanks for all the info guys. So basically, you could bundle 10- 12/2 MCs together without derating?