Mixing NM And Rmored Cable - Electrical - DIY Chatroom Home Improvement Forum


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Display Modes
Old 10-17-2008, 04:27 PM   #1
Member
 
Join Date: May 2008
Location: Edmonton, Alberta Canada
Posts: 777
Rewards Points: 500
Default

Mixing NM and rmored cable


I need to run a wire to a light fixture in a finished ceiling where I know there are steel studs, self tapping screws, and air vent ducts(all bad for an NM cable). I think my best bet would be to run armored cable to the new light fixture. Power to the light switch is 14/2 NM. Whats the best way to make both types of cables work in a similar box? I plan to use a remodel style switch box as well as a remodel style light box.

Advertisement

n0c7 is offline   Reply With Quote
Old 10-17-2008, 04:34 PM   #2
Member
 
Join Date: Sep 2008
Location: Massachusetts
Posts: 270
Rewards Points: 250
Default

Mixing NM and rmored cable


You need a metal box for this one because ac/bx cannot go into a plastic box. Use a non metallic cable clamp for the nm and a bx type clamp with an anti-short (red head) bushing for the armored cable. other than that the wiring is the same. If the switch leg is nm then you can use a plastic box for that part of it. The hard part will be fastening the metal box into the ceiling. If there is a joist, strapping, or wood lathe in the ceiling then you can attach it to the wood with screws.

Advertisement


Last edited by teamo; 10-17-2008 at 04:38 PM. Reason: additional information
teamo is offline   Reply With Quote
Old 10-17-2008, 06:33 PM   #3
Electrician
 
Join Date: Aug 2007
Location: Connecticut, Litchfield
Posts: 2,015
Rewards Points: 1,000
Default

Mixing NM and rmored cable


Quote:
Originally Posted by teamo View Post
The hard part will be fastening the metal box into the ceiling. If there is a joist, strapping, or wood lathe in the ceiling then you can attach it to the wood with screws.
They make metal and plastic round old work boxes.
chris75 is offline   Reply With Quote
Old 10-17-2008, 07:47 PM   #4
Member
 
Join Date: May 2008
Location: Edmonton, Alberta Canada
Posts: 777
Rewards Points: 500
Default

Mixing NM and rmored cable


So will any metal workaround box work to fit the BX or do I need a specific box that accepts the various cable clamps? Just trying to visualize this as I'm only familiar with running NM cable and using the screw type clamps.
n0c7 is offline   Reply With Quote
Old 10-17-2008, 08:10 PM   #5
Electrician
 
Join Date: Aug 2007
Location: Connecticut, Litchfield
Posts: 2,015
Rewards Points: 1,000
Default

Mixing NM and rmored cable


Quote:
Originally Posted by n0c7 View Post
So will any metal workaround box work to fit the BX or do I need a specific box that accepts the various cable clamps? Just trying to visualize this as I'm only familiar with running NM cable and using the screw type clamps.
Being in the trade, I just swap out the straps if needed. But you must use the correct strap and box for the wiring method being used.
chris75 is offline   Reply With Quote
Old 10-20-2008, 01:27 AM   #6
Member
 
Join Date: May 2008
Location: Edmonton, Alberta Canada
Posts: 777
Rewards Points: 500
Default

Mixing NM and rmored cable


I found the right romex ends as well as the BX(ac90) ends, and ended up with a metal conduit box which had 10 different knockout locations on it, and screw holes in various locations making it very easy to attach inside a finished ceiling. Thanks for the help, was an interesting fit.

One question on the BX though - I had trouble shoving those plastic red anti shorts into the cable. It seemed to be very difficult to get over the paper inside the cable. It took me a lot of effort. Does it matter if the anti short goes inside or on top of the paper inside the cable and how far should they insert into the cable?

Advertisement


Last edited by n0c7; 10-20-2008 at 01:29 AM.
n0c7 is offline   Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Top of Page | View New Posts