# Mc & bx



## TOOL_5150 (Aug 27, 2007)

alselec53 said:


> Again after years I forget.. I use MC (metal clad) cable in commercial, what does BX stand for and what is the difference?


mc has a ground conductor, BX or AC does not, the sheath with internal bonding strip is the EGC


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## alselec53 (Jan 4, 2012)

*Mc, bx*

So you would think BX would not be legal with no actual ground? What is AC cable?


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## TOOL_5150 (Aug 27, 2007)

alselec53 said:


> So you would think BX would not be legal with no actual ground? What is AC cable?


bx and ac are referred to the same type of cable, no ground wire, outter sheath may or may not be used as an EGC, depending if the internal bonding strip exists.


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## TOOL_5150 (Aug 27, 2007)

its like greenfield, flex, and FMC... all the same thing... just different names


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## alselec53 (Jan 4, 2012)

I don't think you can ever use the outer metal shieth as a ground, as in pipe, like they use to years ago. Not sure about the bonding strip you talk about.


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## carryyourbooks (Jan 13, 2010)

the difference between mc and ac is how many roto-split blades you have to buy.


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## TOOL_5150 (Aug 27, 2007)

alselec53 said:


> I don't think you can ever use the outer metal shieth as a ground, as in pipe, like they use to years ago. Not sure about the bonding strip you talk about.


ok then. believe what you want. you were the one with a question.


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## TOOL_5150 (Aug 27, 2007)

carryyourbooks said:


> the difference between mc and ac is how many roto-split blades you have to buy.


this is probably the best answer so far. :thumbup:


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## leland (Dec 28, 2007)

MC- not only has the - insulated and or uninsulated ground, It also contains THHN- with a 105C temp rating, Aluminum sheath, This made it popular for many reasons, 1 being you could use the cable for fire alarm wiring, That used to be done in all pipe with THHN- big labor savor!


Look at a peice of old AC (BX) it has a bare wire in it- that was/is the bond strip- with that back wrapped on the sheath, that was your ground/ bond that allowed it to be used in lue of EMT.


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## Shockdoc (Mar 4, 2010)

I have noticed the new generation AC cable has a#12 bare aluminum ground wire. 
I have also come across old 1970's AC cable with a bare #12 cu ground wire.
What good was that #18 aluminum bond wire in older AC wire in the event of a dead short on a oversized breaker?


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## TOOL_5150 (Aug 27, 2007)

Shockdoc said:


> I have noticed the new generation AC cable has a#12 bare aluminum ground wire.
> I have also come across old 1970's AC cable with a bare #12 cu ground wire.
> What good was that #18 aluminum bond wire in older AC wire in the event of a dead short on a oversized breaker?


it helped the sheath transfer the fault current more efficiently, thus tripping the OCP


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## Salvatoreg02 (Feb 26, 2011)

alselec53 said:


> So you would think BX would not be legal with no actual ground? What is AC cable?


Bx= Bronx cable
ac= armored cable
There both the same cable the true technical name is AC. 
AC Has a steel jacket
AC lite is some form of alum.


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## Roger. (Dec 18, 2011)

alselec53 said:


> I don't think you can ever use the outer metal shieth as a ground, as in pipe, like they use to years ago. Not sure about the bonding strip you talk about.


 You haven't spent much time reading 250.118 have you?


Roger


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## Mshea (Jan 17, 2011)

I never knew this

In Canada all of it is called BX and the trade designation is AC. It looks like at 1 time US and Canadidn BX was the same thing.

So in Canada BX (AC) is aluminum armour spiral wound around insulated conductors and paper wrap. the bonding wire is usually bare and at least #14 or 1 size smaller than the current carrying wires. If there is an insulated bonding wire there usually is still a bare copper wire. We are seeing a new AC cable with a bare aluminum wire just under the metal armour and in continuous contact. With the correct connector this aluminum strip can be cut off at the termination without also connecting to the box bonding terminal. I guess a little MC and AC combined?


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## B4T (Feb 10, 2009)

Shockdoc said:


> I have noticed the new generation AC cable has a#12 bare aluminum ground wire.


Is this a bonding strip we use to hold the anti-short bushing on or is it a ground we attach to the box.. :blink:


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## user4818 (Jan 15, 2009)

Shockdoc said:


> I have noticed the new generation AC cable has a#12 bare aluminum ground wire.


It's not technically the ground wire, it can be cut off since the armor is the ground. 



> I have also come across old 1970's AC cable with a bare #12 cu ground wire.


If it contained a bare full sized ground, it was not AC cable. 



> What good was that #18 aluminum bond wire in older AC wire in the event of a dead short on a oversized breaker?


This question shows you have a serious lack of understanding about armored cable types.


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## Roger. (Dec 18, 2011)

Peter D said:


> This question shows you have a serious lack of understanding about armored cable types.


I agree.

Roger


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## Shockdoc (Mar 4, 2010)

Heckle and Jeckle both agree.


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## Bootss (Dec 30, 2011)

Shockdoc said:


> Heckle and Jeckle both agree.


How's business on the east coast these days? Business is pretty good out here in San Fran.Try to keep things casual out here on the west coast.
The local pro football teams just started training camp, football season is just around the corner.Just thought I'd say hello.


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## Shockdoc (Mar 4, 2010)

Lep said:


> How's business on the east coast these days? Business is pretty good out here in San Fran.Try to keep things casual out here on the west coast.
> The local pro football teams just started training camp, football season is just around the corner.Just thought I'd say hello.


Spotty, bidding on a Urgent care med center right now, looks good. Came strongly recommended from her chiropractor friend . I hope for at least three good days a week.


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## Big John (May 23, 2010)

BX (top): Rubber and cambric insulation on the conductors in a paper jacket. Steel armor. No bonding wire or ground wire. No longer manufactured.

AC (bottom): THHN insulation on the conductors in a paper jacket. Steel or aluminum armor. Small bonding wire which makes the armor suitable as a ground.









MC: THHN insulation on the conductors in a plastic jacket. Steel or aluminum armor. No bonding wire. Equipment grounding wire.








-John


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## B4T (Feb 10, 2009)

Shockdoc said:


> Heckle and Jeckle both agree.


Some people enjoy taking the cheap shots.. others enjoy posting useful information..

If everyone knew everything there would be no need for this forum.. :no:


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## Shockdoc (Mar 4, 2010)

B4T said:


> Some people enjoy taking the cheap shots.. others enjoy posting useful information..
> 
> If everyone knew everything there would be no need for this forum.. :no:


With the growing number of clowns , they might have to change the forum name to circus talk.:laughing:


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## user4818 (Jan 15, 2009)

B4T said:


> Some people enjoy taking the cheap shots.. others enjoy posting useful information..
> 
> If everyone knew everything there would be no need for this forum.. :no:


When you have reached a state of perfection, then you will be in a position to judge. :thumbsup:


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## Shockdoc (Mar 4, 2010)

ojo said:


> When you have reached a state of perfection, then you will be in a position to judge. :thumbsup:


I saw you again


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## user4818 (Jan 15, 2009)

Shockdoc said:


> I saw you again


I saw you too:


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## Shockdoc (Mar 4, 2010)

Hows life up on the mountain Pete?


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