Southwire MC Cable

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I just recently wired a residential remodel with MC at the HO's request. (Something to do with minimizing stray RF.) Since there are no ground wires for the inspector to see at rough-in inspection, I'm wondering how he would of reacted. I suspect I would have spent a lot of extra time educating and convincing. Other than that, I like what I saw in the video.
 
Coppersmith said:
I just recently wired a residential remodel with MC at the HO's request. (Something to do with minimizing stray RF.) Since there are no ground wires for the inspector to see at rough-in inspection, I'm wondering how he would of reacted. I suspect I would have spent a lot of extra time educating and convincing. Other than that, I like what I saw in the video.
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You would have to use what Al H said. He called them "auto grounding", the screw is rated or listed for equipment bonding. Although in 250.146(B) it talks about the screws being "in conjunction" with the contact device or yoke, so I don't know. Good luck with an inspector on that one.:D
 
al hildenbrand said:
Actually, all one has to do, to avoid the box to device bonding jumper is to use "auto-grounding devices". The yoke mounting screw is listed as a bonding means and can be use in place of a jumper.

I like MC AP.
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Just quoted you to coppersmith. But not sure, 250.146(B) says the screw in conjunction with a contact device or yoke, is how I'm reading it.
Looking at 250.146(A) it seems the only difference is if it is not self grounding you have to remove one of the insulating washers. You still need direct metal to metal contact with the yoke.
 
hbiss said:
Me too. It looks like the only difference is a larger ground bonding wire and no paper wrap. Only advantage I see is not having to wrap the smaller AC ground wire back (which you really are not required to do) before putting it into the connector and no red head needed.

-Hal
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no red head

I wondered about that the first time I watched the video. I watched the video again and closely watched it showing the Listed grounding box MC connector. Look closely at the connector, it has a red plastic insulated throat. I assume the insulated throat somehow protects the insulated current carrying conductor's insulation from being physically damaged by the sharp inner wall cut edge of the armor, of the MC cable.
 
Just to mention it, in AC, the sheath is the EGC. The bonding strip is there to minimize the inductive effect of the spiral wrap by "shorting" the turn-to-turn coiling of the sheath. That's why it can be so much thinner than an actual conductor would need to be.
 
Jamesco said:
no red head

I wondered about that the first time I watched the video. I watched the video again and closely watched it showing the Listed grounding box MC connector. Look closely at the connector, it has a red plastic insulated throat. I assume the insulated throat somehow protects the insulated current carrying conductor's insulation from being physically damaged by the sharp inner wall cut edge of the armor, of the MC cable.
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I think the theory behind those connectors that "have the redhead built in" like 38AST's or the Arlington 84XX series (for large mc) for example, is that they keep the conductors centered within the sheath so they are less likely to come in contact. None have any material that actually slides in between the sheath and armor like a real redhead. I use redheads pretty religiously on MC, even if I am using the insulated throat type connectors, it makes me sleep warm and snuggly.
 
Jamesco said:
no red head

I wondered about that the first time I watched the video. I watched the video again and closely watched it showing the Listed grounding box MC connector. Look closely at the connector, it has a red plastic insulated throat. I assume the insulated throat somehow protects the insulated current carrying conductor's insulation from being physically damaged by the sharp inner wall cut edge of the armor, of the MC cable.
Click to expand...

To be clear, MC cable does not require a red head. It's not just this MCAP, it's regular MC as well.
 
electrofelon said:
I think the theory behind those connectors that "have the redhead built in" like 38AST's or the Arlington 84XX series (for large mc) for example, is that they keep the conductors centered within the sheath so they are less likely to come in contact. None have any material that actually slides in between the sheath and armor like a real redhead. I use redheads pretty religiously on MC, even if I am using the insulated throat type connectors, it makes me sleep warm and snuggly.
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+1
 
electrofelon said:
I think the theory behind those connectors that "have the redhead built in" like 38AST's or the Arlington 84XX series (for large mc) for example, is that they keep the conductors centered within the sheath so they are less likely to come in contact. None have any material that actually slides in between the sheath and armor like a real redhead. I use redheads pretty religiously on MC, even if I am using the insulated throat type connectors, it makes me sleep warm and snuggly.
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Clarify please.

Are these red heads you like so much, and make you sleep warm and snuggly, bushings or women?

Just curious.:D
 
jumper said:
Clarify please..
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We sleep better, following OEM instructions per 110.3(B).

When OEM's include the bag of Red anti-short bushings, affixed by tie straps to the roll of MC cable, the intent is clear to instruct installers to use them. The image below is clear as it gets without actually tearing off the plastic.

See unopened roll of MC Lite made by AFC, look thru plastic cover and see bag of Red Devils included with the MC cable, by the Original-Equipment Manufacturer. You can also select image and Zoom to see close-up.

No offense to other redheads, especially if the carpets match the drapes.
 
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Ok I guess the conversation has devolved into the red head debate complete with inuendos about women. But....there may be some truth to staying away from redheads.
The bushing type on the other hand, I think it's just a good idea to have that protection against that jagged edge, especially when most people don't even use the correct tool....
 
ramsy said:
We sleep better, following OEM instructions per 110.3(B).

When OEM's include the bag of Red anti-short bushings, affixed by tie straps to the roll of MC cable, the intent is clear to instruct installers to use them. The image below is clear as it gets without actually tearing off the plastic.

See unopened roll of MC Lite made by AFC, look thru plastic cover and see bag of Red Devils included with the MC cable, by the Original-Equipment Manufacturer. You can also select image and Zoom to see close-up.

No offense to other redheads, especially if the carpets match the drapes.
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I ain’t gotta zoom in on nuttin’. Not required. Period.;)

Feel free to waste your time using them all ya want, I simply have no desire to waste mine.:bye:
 
electrofelon said:
Ok I guess the conversation has devolved into the red head debate complete with inuendos about women. But....there may be some truth to staying away from redheads.
The bushing type on the other hand, I think it's just a good idea to have that protection against that jagged edge, especially when most people don't even use the correct tool....
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It is perfectly fine to use them, no question about that.

And yes they add a layer of protection, no question about that either.

I think of it like using a GFCI in just an ordinary area. Extra protection, but not required.

If I have them I usually use them. I mean why not, it only helps.

I just get irritated when someone says I have to with MC. I do not like that.

See post #31, that irks me. My reply in #33 prolly reflects that.:D
 
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I don't use redheads on MC, never have. I have seen exactly one case of damaged insulation at the fitting and it was at the mouth of the fitting, not at the sheathing.

I remember years back a post on here explaining why the send out a bag of them even though they are not required, it had something to do with people kept asking for them and it was easier to send a bag with every roll than handle all the complaints.
 
ActionDave said:
I remember years back a post on here explaining why the send out a bag of them even though they are not required, it had something to do with people kept asking for them and it was easier to send a bag with every roll than handle all the complaints.
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Close.

http://forums.mikeholt.com/showthread.php?t=83435&page=2&p=731952#post731952

ENGINEERING DEPARTMENT
BULLETIN
No. 90

August 14, 2002

Use of Anti-Short Bushings for Terminating Type MC Cable
There has been much confusion within the Installation and Inspection communities regarding the
use of anti-short bushings for terminating Type MC cable. The confusion stems from the fact
that some MC cable manufacturers include anti-short bushings with their cable. The inclusion of
anti-short bushings with coils or reels of MC cable is based on historical practice relating to the
requirements of 320.40 of the NEC, which mandates the use of anti-short bushing or its
equivalent protection for Type AC Cable
Fittings used with Type MC Cable are required to be listed per 330.40 of the NEC. NEMA
supports the use of listed fittings for MC Cable. The design of these fittings may or may not
include an insulated throat however, they are required to be provided with a smooth, rounded end
stop so that the metal sheath of the cable will not pass through and the wires will not be damaged
in passing over the end stop. Whether or not an insulated throat is part of the listed product, these
listed MC fittings do not require an additional anti-short bushing. Anti-short bushings that may
be supplied by MC Cable manufacturers are for optional use by the installer, however they are
not required.


ROP #7-116 from the May 2001 Report on Proposals (ROP) for the 2002 NEC was a proposal
seeking to require anti-short bushings on all MC Cable termination installations.
The following is an excerpt from the Panel statement rejecting the proposal:

Anti-short bushings are not required for Type MC cable in accordance with the listing for
the product. The termination fittings approved for use with Type MC cables are designed
such that the wires will not come in contact with the cut edge of the armor; the throat of
the fitting is small enough to prevent contact with the armor. Type MC termination
fittings perform the same function for Type MC cable as Type AC terminations plus the
anti-short bushing do for Type AC cable.


NEMA supports the uniform adoption and enforcement of the NEC and recommends that local
Authorities Having Jurisdiction follow the requirements of NEC Section 330.40, Boxes and
Fittings for MC Cable. Section 330.40 requires that the fitting be listed, but does not mandate the
use of an anti-short bushing.

Distribution List:

Standards and Conformity Assessment Policy Committee
Codes and Standards Committee
NEMA Executive Staff
 
I have always used them but have never required anyone too and Jumper's post #36 should pretty well put the last nail in the coffin.
 
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