Wiring question about recessed luminares

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wrestless

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Can you wire in and out of 1 2x4 drop in to another and so on with MC cable or do you have to have a splice box with a whip ? Any help with this ?
 
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jeremysterling

Senior Member
Location
Austin, TX
Of course, both replies to the OP are correct. The tricky part is properly supporting the MC. The 330.30(D) rules do not apply if the MC is longer than 6' (that is wirenut to wirenut), and if your troffers are separated by a four foot tile, I doubt your MC will be less than 6'.
 
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TNGuy81

Member
Location
Nashville TN
That is fine with MC cable in a drop ceiling and its not hard at all to support if its longer than 6' its not a prob. Use the caddy supports. I call them bat wings I dont know the real name of them but they look like batwings. They attach to the grid wire and hold the MC cable into place. I like also the quick connects the best vrs the ones with the set screws. They come with a insulated throat(red) which most think is suitable as a little red head (anti short bushing) but its not. You need to still use the L.R.T.'s when terminating the MC.
 
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T

TNGuy81

Member
Location
Nashville TN
lol yup! Little red things/thingies is exactly right!:) I always use the LRTs and every foreman I have worked for told me use them also. There is a reason they come with the a bag with the MC cable. It may not be "code" but its safe practice.
 
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iwire

iwire

Moderator
Staff member
Location
Massachusetts
jeremysterling said:
Of course, both replies to the OP are correct. The tricky part is properly supporting the MC. The 330.30(D) rules do not apply if the MC is longer than 6' (that is wirenut to wirenut), and if your troffers are separated by a four foot tile, I doubt your MC will be less than 6'.
Click to expand...

Where are you getting wirenut to wirenut?

330.30(D)(2)Is not more than 1.8 m (6 ft) in length from the last
point of cable support to the point of connection to
luminaires or other electrical equipment and the cable
and point of connection are within an accessible ceiling.
For the purpose of this section, Type MC cable
fittings shall be permitted as a means of cable support.
Click to expand...
 
H

haskindm

Senior Member
Location
Maryland
TNGuy81 said:
That is fine with MC cable in a drop ceiling and its not hard at all to support if its longer than 6' its not a prob. Use the caddy supports. I call them bat wings I dont know the real name of them but they look like batwings. They attach to the grid wire and hold the MC cable into place. I like also the quick connects the best vrs the ones with the set screws. They come with a insulated throat(red) which most think is suitable as a little red head (anti short bushing) but its not. You need to still use the L.R.T.'s when terminating the MC.
Click to expand...

Look at 300.11(A)(2). You will need to install ADDITIONAL support wires for the "batwings" you cannot use the ceiling support wires to support wiring.
 
T

TNGuy81

Member
Location
Nashville TN
True. You have to supply your own grid wire(usually the grid guys will hook you up with some.) You can not hang off the actual ceiling grid wire for the ceiling. This is true for any electrical application with MC/EMT/PCV/etc you cannot support it off anything other that what you provide. You cant strap to duct work, existing grid wire, the HVAC guys uni-strut/etc.. Now obviously drywall, brick, or red iron is fine for EMT/Rigid conduit/MC cable. Basically the structure or the building.

Art 300.11(A)(2) also has an exception though.

The ceiling support system shall be permitted to support branch-circuit wiring and associated equipment where installed in accordance with the ceiling system manufactures instructions

I have strapped to the existing myself more than a handful of time (at the time not knowing I couldnt by "code") and the inspector never said a word. Im not saying thats right, but i am guilty of doing that.
 
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