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Supporting MC Cable in Acoustical Ceiling

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Armydad

New User
Location
Pompano Bch, Fl
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Electrical Contractor
Recently been called out over improper support of our MC Cable, We have our own ceiling wires supporting our light fixtures and they are also painted for easy identification, we attached our MC to our independent light fixture wire and was told that was a violation and are required to add a additional wire to support the MC...
 
tom baker

tom baker

First Chief Moderator & NEC Expert
Staff member
Location
Bremerton, Washington
Occupation
Master Electrician
Not required. The NEC has clarified that the MC fitting is considered support. This change was submitted by the armored cable mfgs association many code cycles ago.
I dont have the code section available right now.
 
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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
I think the OP is referring to mc not related to or not related to the fixture. But I don’t know of anything prohibiting it. It’s independent of the ceiling support.
 
augie47

augie47

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Staff member
Location
Tennessee
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State Electrical Inspector (Retired)
I see it done that way often and had not given it a 2nd thought, however there is wording in 300.11 that might give credibility to such a call:
" Where independent support wires are used, they shall be secured at both ends". .
" An independent means of secure support shall be provided and shall be permitted to be attached to the assembly"
 
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jusme123

Senior Member
Location
NY
Occupation
JW
tom baker said:
Not required. The NEC has clarified that the MC fitting is considered support. This change was submitted by the armored cable mfgs association many code cycles ago.
I dont have the code section available right now.
Click to expand...
330.30(D)(3) last sentence
 
M

macmikeman

Senior Member
Location
Planet macmikeman
I often support mc cables not from the existing ceiling suspension wires, but from the same hook they are hanging from that penetrates the concrete of the floor above. I know it's a grey area , but I have read the code about it often enough to be able to argue this fine point of chicanery with precision and win . The code states that you are not allowed to support cables from the existing suspension wires. It does not say you are not allowed to support from a hooked "nail" shot into the ceiling that is meant to support said ceiling wires. Other times I will set a quarter/20 threaded rod and drop anchor and use a bunch of K-12'S or K-16's hanging off that 1/4" rod, with maybe a mineralac hanger at the bottom of it all for one more cable run. Wires have to be secured to the grid. As far as I know, hanging rods do not.
 
LarryFine

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
macmikeman said:
Other times I will set a quarter/20 threaded rod and drop anchor and use a bunch of K-12'S or K-16's hanging off that 1/4" rod, with maybe a mineralac hanger at the bottom of it all for one more cable run. Wires have to be secured to the grid. As far as I know, hanging rods do not.
Click to expand...
I have been called on that. "Supported and secured" includes lateral support, too.
 
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