MC connector

I must admit that I have learned a lot from this interesting thread, particularly about the mystery of Armored Ground Wire (or Cable) installation.


I had asked a few manufacturers on the product installation, and here are the answers from two companies. Other companies didn't want to give information about how to install their products, which I was very surprised.

AFC Cable Systems: how to install bare armored grounding cable, part # 1301-42-00

From: Picard, Paul [mailto:pPicard@atkore.com]
Sent: Friday, April 29, 2016 9:29 AM
To: Brian Dang
Cc: afcmarketing <a1e2229@atkore.com>; Barry, Jay <JBarry@atkore.com>; Campbell, David <DCampbell@atkore.com>; Lyons, Lindsay <LLyons@atkore.com>; Reis, Paul <PReis@atkore.com>; Straniero, George <GStraniero@atkore.com>; Vertente, Mike <MVertente@atkore.com>
Subject: RE: AFCweb.com Contact Submission about Product Information Request

APR 29, 2016

Brian:
Yes the armor of the Bare Armored Ground should be bonded at both ends. The bonding can be accomplished through the use of listed fittings at each termination.

Regards,
Paul R. Picard
Product & Design Engineering Manager
AFC Cable systems, Inc.

From: afcmarketing
Sent: Friday, April 29, 2016 11:23 AM
To: Picard, Paul
Cc: Barry, Jay
Subject: FW: AFCweb.com Contact Submission about Product Information Request

Hi Paul,

Please answer Brian’s question below.

Thanks
Lindsay

Lindsay Lyons|Marketing Communications, Cable Solutions
Atkore International | 960 Flaherty Dr | New Bedford, MA 02745
Office: 508.985.1240

From: Brian Dang
Sent: Thursday, April 28, 2016 3:00 PM
To: afcmarketing
Subject: AFCweb.com Contact Submission about Product Information Request

Comments
1301-42-00

Re to part # 1301-42-00, bare armored grounding cable, for using as Grounding Electrode Conductor. Since the armor is a ferrous steel material, does the armor need to be bonded at each end to the copper wire that the armor enclosed, per NEC 2011 250.64?

Best Regards,
Brian





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Duraclad Bare Armored Ground Cable, part # 55-16-01-01


Subject: RE: product_support

Brian,

Thought about it a bit further and talked with another code savvy person. Actually, I change my recommendation to be in favor of bonding the armor. The reason why? When the GEC is routed into the main panel, the armor is in the vicinity of live conductors. While the probability of live voltage coming into contact with the armor is very low, we do not want to have the possibility of live voltage on an ungrounded conductive material that is outside the panel.

As far as the concern about inductive loading by the ungrounded ferrous cable armor around the GEC, that may be a legitimate concern. I can appreciate that the inductive loading will oppose the sudden inrush of current to the grounding electrode. Since my recommendation is (now) to bond the armor, I will leave this research for another time.

BTW - I have started serving on NEC code panels and taking a lawyer's approach is required when interpreting the code among many competing interests.

Dave


Dave Watson
Sr. Applications Engineer
Electrical Division
Research & Development
Southwire Company
Cofer Technology Center
111 Development Drive
Carrollton, GA 30117
770-832-5059


Subject: RE: product_support

Brian,

We do not manufacture clamps and connectors. I don't have any specific recommendations. Some manufacturers of MC fittings (similar to an armored ground cable) are Arlington, Bridgeport, American Fittings, Crouse Hinds, Thomas & Betts, Panduit (one of their businesses), etc., ....

Dave


Dave Watson
Sr. Applications Engineer
Electrical Division
Research & Development
Southwire Company
Cofer Technology Center
111 Development Drive
Carrollton, GA 30117
770-832-5059


-----Original Message-----
Subject: RE: product_support

Dave,

In this statement under 250.64 (E), " Ferrous (iron/steel) raceways, boxes, and enclosures containing the grounding electrode conductors" , I think the word raceways was used to mean rigid metal conduit, EMT, steel armor etc., in its context -- enclosing a single conductor for a short connection to the grounding electrode, and not multi current carrying conductors . One could use the word enclosure instead of raceway for the armor, since it is enclosing the conductor inside. Are we talking like lawyers or should we apply engineering practices to make a safe product -- using grounding electrode conductor proper way? I understand raceway generally is used to mean the conductive conduit enclosing hot, neutral, and EGC inside.

Anyway, could you give suggestion of what type of clamps and connectors for connecting this product?

Best,
Brian



-----Original Message-----
Subject: RE: product_support

Hi Dave,

As you said, (B) allows the use of cable armor such as the one used on this part #55-16-01-01 for physical damage protection. However (E) states that any ferrous raceways must have each end of the raceway bonded to the conductor it enclosed. Please see below. Does this product have ferrous or non-ferrous material for the armor part? What would be the recommended method for bonding one end to the service panel and the other end to the grounding rod (grounding electrode), clamp and connector part numbers? We could ask the local AHJ about the installation, but I would seek the advice of a product engineer for the right way of using for best performance.


From NEC 2011, 250.64 Grounding Electrode Conductor Installation.
(B) It shall be protected in rigid metal conduit (RMC), intermediate metal conduit, (IMC) rigid polyvinyl conduit (PVC), reinforced thermosetting resin conduit (RTRC), electrical metallic tubing (EMT), or cable armor.

(E) Enclosures for Grounding Electrode Conductor. Ferrous (iron/steel) raceways, boxes, and enclosures containing the grounding electrode conductors must have each end of the ferrous metal raceway, box, and enclosure bonded to the grounding electrode conductor [250.92(A)(3)]. Figure 250.115

Regards,
Brian



-----Original Message-----
Subject: product_support


Message: Re to part # 55-16-01-01, bare armored grounding cable, for using as Grounding Electrode Conductor. Since the armor is a steel material, does the armor need to be bonded at each end to the copper wire that the armor enclosed, per NEC 2011 250.64?

Best Regards,
Brian
 
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