# Steel AC (BX) cable in NYC



## MDShunk (Jan 7, 2007)

I don't know the answer, to say it plainly, but I have a guess. Many large metropolitan areas use certain methods and materials more out of tradition and superstition than any particular mandate or legal requirement.


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## wildleg (Apr 12, 2009)

this is the subsection of the NYC addendum for article 330:



> ARTICLE 330
> Metal-Clad Cable: Type MC
> SECTION 330.10
> Subsection 330.10(A)(1) - Delete the word "services".
> ...


(apparently they are still on nec2008)

based on that, it appears Shunk's post is correct (unless I'm missing something)

here's the links:
https://www1.nyc.gov/assets/buildings/pdf/ll39of2011_electrical_code.pdf

https://www1.nyc.gov/site/buildings/codes/electrical-code.page

of course, that doesn't preclude alternative realities that may exist, such as perhaps some mob bosses owning warehouses full of BX they stole years ago. who knows.


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## TGGT (Oct 28, 2012)

MTW said:


> Is there a reason why steel jacketed AC cable is still popular in NYC and surrounding areas? Is there a local code to use it instead of MC cable?


Do they still use the 2 wire?

Sent from my SM-G930T using Tapatalk


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## MTW (Aug 28, 2013)

TGGT said:


> Do they still use the 2 wire?


Not sure what you mean, but yes, type AC cable does not have a separate wire EGC, if that's what you mean.


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## MDShunk (Jan 7, 2007)

12/2 MC - 495.01/M
12/2 AC - 594.30/M

Hundred bucks a thousand more, but one less termination to make up. Possible labor savings. Paper interleaving is easier to snap off rather than having to cut off. Makes box prefab a little more possible and field makeup quicker. Armor can't be 'snapped-and-snipped' easily like MC.

I dunno. There's plusses and minuses. I don't favor type AC simply because it's dirtier than MC, but they'll both makes a mess of your hands.


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## MTW (Aug 28, 2013)

MDShunk said:


> I don't know the answer, to say it plainly, but I have a guess. Many large metropolitan areas use certain methods and materials more out of tradition and superstition than any particular mandate or legal requirement.


I was thinking along those lines, but then again, NYC has a handful of codes that go above and beyond the NEC. Looks like wildleg debunked the local code theory, so it's just down to tradition.

FWIW the use of AC cable died out here in the 1980's in favor of MC cable, no doubt due to the local influence of AFC Cables which manufacturers nearby. I have not seen AC cable used in any new buildings, and certainly not in the last 20 or so years.


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## MTW (Aug 28, 2013)

MDShunk said:


> 12/2 MC - 495.01/M
> 12/2 AC - 594.30/M
> 
> Hundred bucks a thousand more, but one less termination to make up. Possible labor savings. Paper interleaving is easier to snap off rather than having to cut off. Makes box prefab a little more possible and field makeup quicker. Armor can't be 'snapped-and-snipped' easily like MC.
> ...


HD sells them both for around the same price. That probably doesn't matter if you're getting Carlon blues to jam it into. :vs_laugh:

https://www.homedepot.com/p/AFC-Cab...ft-BX-AC-90-Solid-Cable-1404N42-AFC/205070960

https://www.homedepot.com/p/Southwi...Metal-Clad-Armorlite-Cable-68580055/202316559

I'm not even sure AC is stocked locally at the wholesalers anymore. Probably not.


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## MDShunk (Jan 7, 2007)

MTW said:


> I'm not even sure AC is stocked locally at the wholesalers anymore. Probably not.


It's not stocked where I buy presently. I actually had to call and get the type AC cable price. I guessed it would be cheaper (one less copper conductor), but wasn't too terribly surprised to find it a hundred bucks a thousand more. Supply and demand. Probably in market areas where it's still traditionally used it might (or, should) be cheaper than type MC.


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## MDShunk (Jan 7, 2007)

MTW said:


> Is there a reason why steel jacketed AC cable is still popular in NYC and surrounding areas? Is there a local code to use it instead of MC cable?


I forgot to ask: What makes you feel type AC cable in popular in the NYC area over type MC, pipe-n-wire, or any other wiring method? This is something I may have heard before, but my memory sucks of late.


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## MechanicalDVR (Dec 29, 2007)

Been a long while but there is something in NYC building code about being for rodent proofing.


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## MTW (Aug 28, 2013)

MDShunk said:


> I forgot to ask: What makes you feel type AC cable in popular in the NYC area over type MC, pipe-n-wire, or any other wiring method? This is something I may have heard before, but my memory sucks of late.


I noticed it being used in some assorted pics of wiring I saw in the NYC area. I think I also saw it used in a YT video where someone made some alterations to a condo or apartment in NYC, and AC cable was used once again. So then I dug into it a little more.


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## MDShunk (Jan 7, 2007)

I really think it's tradition since it's been long-rumored to have been conceived in NYC. The old stuff is getting dangerous anyhow. Cloth insulated wires inside in very close proximity to the steel armor.


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## MTW (Aug 28, 2013)

MDShunk said:


> I really think it's tradition since it's been long-rumored to have been conceived in NYC. The old stuff is getting dangerous anyhow. Cloth insulated wires inside in very close proximity to the steel armor.


We still have a ton of that stuff here. I always tell people without hesitation that it's an extreme hazard, far worse than K&T. No other wiring method turns into a toaster coil inside your walls should a fault occur.


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## MDShunk (Jan 7, 2007)

MTW said:


> MDShunk said:
> 
> 
> > I really think it's tradition since it's been long-rumored to have been conceived in NYC. The old stuff is getting dangerous anyhow. Cloth insulated wires inside in very close proximity to the steel armor.
> ...


Agreed. I'd live comfortably in a K&T wired home without a second thought. Old cloth insulated type AC cable would have me checking my fire insurance coverage.


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## gnuuser (Jan 13, 2013)

MTW said:


> Is there a reason why steel jacketed AC cable is still popular in NYC and surrounding areas? Is there a local code to use it instead of MC cable?


for the same reason it and often conduit is used in many other cities,
any chance there is a possibility of rodent infestation either rats, mice, and or squirrels.
it may be a pain in the but to use but critters have one hell of a time trying to chew through it.:devil3:


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## MTW (Aug 28, 2013)

MDShunk said:


> Agreed. I'd live comfortably in a K&T wired home without a second thought. Old cloth insulated type AC cable would have me checking my fire insurance coverage.



The next time I get my hands on an old piece of BX with the rubber and cloth insulation I'd like to rig an experiment up and see if I can get the jacket to glow red.


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## lighterup (Jun 14, 2013)

MTW said:


> The next time I get my hands on an old piece of BX with the rubber and cloth insulation I'd like to rig an experiment up and see if I can get the jacket to glow red.


I've seen this happen live in action. It travels pretty quickly from the
source to the load...the speed was that of the old type explosive fuse
that you light with a match


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## nrp3 (Jan 24, 2009)

Short to jacket without the tail that’s in new BX/AC is what causes that? I’d like to see that in a video. I’m not likely to demo any until August, though that may be cloth ungrounded romex, another kitchen gut.


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## MTW (Aug 28, 2013)

nrp3 said:


> Short to jacket without the tail that’s in new BX/AC is what causes that? I’d like to see that in a video. I’m not likely to demo any until August, though that may be cloth ungrounded romex, another kitchen gut.


Yes, the impedance of the jacket without the small aluminum bonding strip to short out each spiral is quite high. That's what makes that old stuff so dangerous. It's basically a massive inductor, which limits current of course.


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## Unionpride277 (Oct 31, 2018)

A lot of it is older codes in nyc that people just stick with the a/c is one .

And a junction box at every light I have seen aswell .

Instead of going in and out of the fixture ,I wrked for a company that would put up a 4”square at every light and would splice a wip down to the fixture .

Seemed like a waste of time to me but I was told it’s nyc code .


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## lighterup (Jun 14, 2013)

Here , once you leave the interior of the building , pentetrate the vapor barrier (even if it's just a leg to an exterior wall mounted light fixture) , you have to sleeve it....particularly
if your running wire in NM. Also can't use stackets on the exterior walls,.. Inspectors say it messes up the R value of the insulation....same thing running in attic above ceiling.
Also...romex staples can only have 1 NM cable under a staple and we are allowed to use the little hole in a panel for the GEC to pass thru even though it may blow up.


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## MDShunk (Jan 7, 2007)

lighterup said:


> Also...romex staples can only have 1 NM cable under a staple ...


Even though the manufacturer says the staple is rated for as many as the staple will securely hold?


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## lighterup (Jun 14, 2013)

MDShunk said:


> Even though the manufacturer says the staple is rated for as many as the staple will securely hold?


you completely missed it:vs_laugh:...
while you were sticking it out on your MTW boycot
there were some conversations between certain 
members that became kind of redundent but very 
humorous.


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## jelhill (Nov 11, 2018)

MDShunk said:


> I don't know the answer, to say it plainly, but I have a guess. Many large metropolitan areas use certain methods and materials more out of tradition and superstition than any particular mandate or legal requirement.


Amen! We have some squirrelly local codes in our area. That might be a good subject for a new post/thread.... “SQUIRRELLY LOCAL CODES” :vs_laugh:


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## jelhill (Nov 11, 2018)

MDShunk said:


> I don't know the answer, to say it plainly, but I have a guess. Many large metropolitan areas use certain methods and materials more out of tradition and superstition than any particular mandate or legal requirement.


I have also encountered some small cities and counties that have their own (Sometimes strange) twists on the code.


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## Unionpride277 (Oct 31, 2018)

In nyc I also remember they do not use emt out side .

and I belive you can’t use Pvc as a service riser.

They want you to use imc , or rmc


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## MDShunk (Jan 7, 2007)

lighterup said:


> you completely missed it:vs_laugh:...
> while you were sticking it out on your MTW boycot
> there were some conversations between certain
> members that became kind of redundent but very
> humorous.


No idea what you're talking about.


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## Unionpride277 (Oct 31, 2018)

If I remember correctly nyc also dosnt have a rough in inspection .


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