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#181423 - 10/07/08 11:06 AM Redundant Ground MC
gunther Offline
Member

Registered: 09/17/03
Posts: 59
I haven't found any information about how to terminate the redundant ground wire that comes in the green mc that is suitable for patient care areas. One opinion was to fold it back over the mc and make sure the mc fitting clip caught it, another was to wrap it around the outside grooves of the mc and catch it with the clip, and another was to use land it under the bolt that tightens the clip.
My thought would be to just make it up with the regular ground in the device box.
Is there a detail on this proceedure that I am missing?

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#181424 - 10/07/08 11:36 AM Re: Redundant Ground MC [Re: gunther]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA
Just fold it back, and cut it off at the armor, if you're talking about Southwire's product.

http://www.southwire.com/processGetPage.do?bp=featuredProduct.jsp

Click on "view installation steps"




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#181426 - 10/07/08 01:30 PM Re: Redundant Ground MC [Re: electure]
gunther Offline
Member

Registered: 09/17/03
Posts: 59
Thanks, that helps a lot. Although the mc shown isn't the type suitable for patient care areas, with the insulated green ground and also the bare redundant ground that accompanies it, it does explain that the ground is sufficient because it is in contact throughout and evidently the fitting is sufficient for continuous ground purposes.
The only question I might have is that this type of mc is green in color and I wonder if it is a non-conductive paint. I appreciate your help.

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#181427 - 10/07/08 01:47 PM Re: Redundant Ground MC [Re: gunther]
gunther Offline
Member

Registered: 09/17/03
Posts: 59
Update: I just called the manufacturer and they say that it has been tested to perform excellently when the bare conductor is cut off where it comes out of the jacket.

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#181436 - 10/07/08 06:30 PM Re: Redundant Ground MC [Re: gunther]
SolarPowered Offline
Member

Registered: 07/05/04
Posts: 615
Loc: Palo Alto, CA, USA
Just FYI, I believe that the HCF cable is actually AC cable, not MC.

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#181437 - 10/07/08 07:11 PM Re: Redundant Ground MC [Re: SolarPowered]
electure Offline

Member

Registered: 12/24/00
Posts: 4225
Loc: Fullerton, CA USA
It's MC, a type that came out recently.

From the site linked to above:

"UL-listed and NEC-compliant MCAP and HCF MCAP can replace conventional AC or MC cable in a broad range of applications."


Edited by electure (10/07/08 07:27 PM)
Edit Reason: add some info

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#181438 - 10/07/08 07:21 PM Re: Redundant Ground MC [Re: electure]
SolarPowered Offline
Member

Registered: 07/05/04
Posts: 615
Loc: Palo Alto, CA, USA
According to http://www.afcweb.com/faq_.html

 Quote:
What's the difference between HCF and MC cable?

The difference between HCF and MC cables (as manufactured by AFC Cable Systems) is the grounding capabilities of the cable assemblies.

Type HCF cable has a green grounding conductor plus the armor/bond wire combination, thereby providing redundant or isolated grounding capability. HCF is a Type AC cable and is manufactured in accordance with U.L. 4.

Perhaps someone else manufactures an HCF cable that's type MC.

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#181440 - 10/07/08 07:34 PM Re: Redundant Ground MC [Re: SolarPowered]
SolarPowered Offline
Member

Registered: 07/05/04
Posts: 615
Loc: Palo Alto, CA, USA
Too late to edit my previous post: Now that I'm thinking about it, I do recall an announcement a couple years ago that somebody was making an MC version of HFC.

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#181824 - 11/02/08 08:11 AM Re: Redundant Ground MC [Re: SolarPowered]
watersparkfalls Offline
Member

Registered: 03/08/05
Posts: 210
Loc: Washington...Not DC
I know this has been answered already but,
the idea of grounding with the conductors wouldn't work for two reasons. 1-its aluminum and conductors are copper and 2-that bonding jumper is very thin(16awg ?) and breaks very easily...but diffrent metals cant be tied directly tgether.

H20

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#181827 - 11/02/08 08:51 AM Re: Redundant Ground MC [Re: watersparkfalls]
gfretwell Offline

Member

Registered: 07/20/04
Posts: 9012
Loc: Estero,Fl,usa
The bonding conductor in the new MC cable is not that little strip you had in type AC. This is larger than the circuit conductors and in tight contact with the armor
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Greg Fretwell

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