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#92178 - 03/03/05 04:00 PM Armored Cable
jes Offline

Registered: 07/12/02
Posts: 103
Loc: CT
Armored cable is required to have " internal bonding strip of copper or aluminum in intimate contact with the armor for its entire length." (320.100).
Such was not always the case.
Can anyone give me a Code edition reference for when the bonding strip was first required? My understanding is that it was in the later 1950s or early 1960's.

2014 / 2011 NEC & Related Books and Study Guides
#92179 - 03/03/05 06:09 PM Re: Armored Cable
Ron Offline

Registered: 03/13/02
Posts: 577
Loc: White Plains, NY
According to a website it was 1959:
BX is the common trade name for AC. BX was the trademark of cable made by G.E.'s Sprague Electric division.
189?- Gus Johnson and Harry Greenfield patent AC
1910- AC receiving acceptance.
1920s or the early 1930s widespread adoption.
1932 NEC- Armored cable was officially called Type AC
1952- Aluminum clad AC introduced.
1959 NEC- Aluminum bonding wire required under metal sheathing.

#92180 - 03/03/05 07:18 PM Re: Armored Cable
safetygem Offline

Registered: 01/30/02
Posts: 114
Loc: Ohio, USA
Just took a look in the 1959 NEC Handbook (yep, I've got one laying around.)

It was added in 1959. Also, just as an FYI, the 1959 was the first year the NEC used the current numbering scheme.

Here is the text from Article 334 Armored Cable (yep, 334 was AC not NM back then):
334-2(a) Armor. All types of armored cables except Types ACL and ACV, in all sizes, shall have an internal bonding strip of either copper or aluminum in intimate contact with the armor for its entire length.

#92181 - 03/06/05 03:57 PM Re: Armored Cable
jes Offline

Registered: 07/12/02
Posts: 103
Loc: CT
Thanks people.
Safety, is there any way I can get a copy of the Art 334 text and the title page of the '59 Code?

#92182 - 03/06/05 05:00 PM Re: Armored Cable
Joe Tedesco Offline

Registered: 10/07/00
Posts: 3325
Loc: Boston, Massachusetts USA
Yes, call the NFPA Library they can send copies to you of that information.

Joe Tedesco, NEC Consultant


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