BX or MC
- Thread starter EEC
- Start date
- Status
bdarnell
Senior Member
- Location
- Indianapolis, IN
- Occupation
- Retired Engineer
By BX, I assume you mean AC.
Around here, my suppliers aren't even stocking AC much anymore, except for HCFAC. I see no advantage to AC over MC. It used to be a little less expensive, but if nobody stocks it, that's a moot point.
Around here, my suppliers aren't even stocking AC much anymore, except for HCFAC. I see no advantage to AC over MC. It used to be a little less expensive, but if nobody stocks it, that's a moot point.
tonyi
Senior Member
Some old work situations where you don't want to tear a wall up to put a new box in might call for AC. ex. orignal wire was old BX, someone has paneled over plaster since the original stuff went in and getting a 2" shallow box out means mangling up/down at least to the plaster ears.
That 2" box, using the internal clamp, is only good for (5) #14's -- 3 of which are already burned by the clamp and your switch/receptical. Its not even legal to fish a 14-2 romex into that box somehow if you have to use an internal clamp.
That 2" box, using the internal clamp, is only good for (5) #14's -- 3 of which are already burned by the clamp and your switch/receptical. Its not even legal to fish a 14-2 romex into that box somehow if you have to use an internal clamp.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
One major difference is installation time. On a large job with hundreds of devices AC cable is a big timesaver when it comes to terminations. This would eliminate all splicing and tailing of the EGC out to devices and to the box, as long as a self-grounding receptacle is used. Also, each 2 wire homerun in MC will require 50% more terminations in the panel and at each junction box. Depending on what you pay for labor, there could be substantial savings when using AC cable over MC cable.
Another advantage of AC is that it is permissable to run on the underside of joist as long as it is supported at every joist.
In old work applications where there are cold air returns and mechanical ducts and pipes, this is a great way to "get around" such obstructions
without drilling/boring holes or running conduit etc.
In old work applications where there are cold air returns and mechanical ducts and pipes, this is a great way to "get around" such obstructions
without drilling/boring holes or running conduit etc.
peter d
Senior Member
- Location
- New England
Gmack said:
MC cable can be run on the underside of joists too. It is only required to be secured every 6', not every joist that AC requires, giving it a distinct advantage over AC. MC is one of the most versatile methods available.
- Location
- Massachusetts
Gmack said:
That is not how it works, if your the inspector you have to cite where it says I can't.
By the way.....I can run MC exposed with 6' supports. 8)
peter d
Senior Member
- Location
- New England
Gmack said:
Cite the article that says I can't.
Bob is correct (as usual.) The NEC is permissive. If it doesn't say I can't, then I can. If you don't like it, too bad.- Status