On 12/7/2011 4:18 PM, wrote:
On Wed, 07 Dec 2011 09:02:36 -0600,
wrote:

On 12/6/2011 7:25 PM, wrote:
On Tue, 06 Dec 2011 18:54:44 -0500, wrote:

On Tue, 06 Dec 2011 17:16:28 -0500, wrote:

I Incorrectly call it a ground?? Check your facts. I have always
called it a bonding strip, which, by the way ALLOWS the metallic
sheath to be used as a ground. And that bonding strip is NOT part of
the "AC" spec, it is part of the "MC" spec.
Type "MC" armoured cable can use the sheath as a ground, while type
"AC" cable requires the additional bare or insulated ground.


You have that backward MC is the one that needs a ground wire unless
it is the new "Smart MC" from Southwire. AC can always use the armor
as ground.

From the NEC
320.100 Construction.
Type AC cable shall have an armor of flexible metal tape and shall
have an internal bonding strip of copper or aluminum in intimate
contact with the armor for its entire length.

Handbook commentary
The armor of Type AC cable is recognized as an equipment grounding
conductor by 250.118. The required internal bonding strip can be
simply cut off at the termination of the armored cable, or it can be
bent back on the armor. It is not necessary to connect it to an
equipment grounding terminal. It reduces the inductive reactance of
the spiral armor and increases the armor's effectiveness as an
equipment ground. Many installers use this strip to help prevent the
insulating (anti-short) bushing required by 320.40 (the €œred head€�)
from falling out during rough wiring.

And the antishort is not required with the proper connectors on the
cable with the aluminum bond strip.

Do you have a link to a "proper" type AC connector for the US that does
not need an antishort?


OK - you may have gotten me mixed up - AC to MC.

AC has the bond strip and the sheath can be used as safety ground.
MC does not have the bond strip and requires a separate safety ground
(bare or insulated)

An AC cable an antishort is required, while on MC it is NOT required
by NEC if approved connectors are used. See:
http://www.kaf-tech.com/pdf/KT0609_pocket_guide.pdf, particulary page
13.
It states "Insert the cable into the connector and secure the
connector into the box. Be sure that the anti-short bushing
is plainly visible in the connector for easy inspection. The
same procedure is followed for MC cable with the exception
that there is no bonding wire. Although anti-short bushings
are only required by the NEC for AC cable, most
manufacturers recommend their use with MC cable."

That link was to a very good source and a copy of the brochure went into
my electrical reference data base. Hopefully, this thread can
now die happy. ^_^

TDD