frangible BX connectors

[GoldDigger]

I'm confused:?, how did the OP go from

SceneryDriver

Senior Member

to


lightmedic

Junior Member

Original Post: "I helped a friend...."
Maybe the friend joined in in mid thread?
Both talking about the same house?

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[hbiss]

No matter how good that old BX looks it still has to go because it has no bonding tape and can't be used for the EGC on grounding receptacles, metal boxes, etc.

-Hal

 

[Little Bill]

Original Post: "I helped a friend...."
Maybe the friend joined in in mid thread?
Both talking about the same house?

Sent from my XT1585 using Tapatalk

Friend joined in 2014

Not important.....just confusing.

 

[GoldDigger]

Friend joined in 2014

Not important.....just confusing.

I said "joined in", as in the thread, not "joined".

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[SceneryDriver]

Original Post: "I helped a friend...."
Maybe the friend joined in in mid thread?
Both talking about the same house?

Sent from my XT1585 using Tapatalk

Yes. This exactly. Lightmedic is a friend of mine, and we were working on the MIL's new house.



SceneryDriver

 

[al hildenbrand]

No matter how good that old BX looks it still has to go because it has no bonding tape and can't be used for the EGC on grounding receptacles, metal boxes, etc.

Type AC armored cable was first introduced in regulatory language by the 1913 NEC. No additional wiring, other than the tight mechanical assembly of cable, connectors, boxes and fittings, was necessary to establish a ground path, per the 1913 NEC, and later NECs.

As for the armored cable shown and described in this thread, the absence of the bonding strip has not been stated nor shown. In the photo that I tweaked from a PDF into a JPEG, one cannot see the emergence of the conductors from the steel sheath. The bonding strip, while many times wrapped around the outside of the armor prior to application of the connector, does not have to be so, and, in fact, could simply be cut off.

 

[hbiss]

Agreed, but when AC was first introduced there were no grounding receptacles though it was still important for the armor to carry any fault current enough to blow the fuse. We have since found that due to corrosion the spiral armor develops a high resistance thus in the late 50's (I believe) a bonding tape was required in all type AC cable construction. My observation was that it first began appearing in the larger sizes (#12 on up) then #14.

From the OPs description of his cable I believe it predates the bonding tape requirement. My policy is to remove any of that old AC whenever I can.

-Hal

 

[wwhitney]

Type AC armored cable was first introduced in regulatory language by the 1913 NEC. No additional wiring, other than the tight mechanical assembly of cable, connectors, boxes and fittings, was necessary to establish a ground path, per the 1913 NEC, and later NECs.

Whether that ground path continues to be recognized by later NECs is a matter of debate, as we both know. Either way, my understanding is that subsequent experience has shown that the ground path furnished by Type AC cable without a bonding strip does not reliably provide sufficiently low impedance to facilitate the operation of OCPD during a ground fault.

Cheers, Wayne

 

[al hildenbrand]

Agreed, but when AC was first introduced there were no grounding receptacles though it was still important for the armor to carry any fault current enough to blow the fuse.

Yes, When type AC armored cable was introduced in the NEC, there were grounding requirements for the frames of electric motors and generators, not blanket requirements, but requirements none the less. And additional grounding requirements were added every NEC edition. Non bonding strip type AC armored cable served as the grounding means, by NEC, for those requirements.

While the grounding type receptacle didn't exist in 1913, it was patented in 1928 by Philip F. Labre, patent # 1627067. 1928 is roughly thirty years before the 1950s construction change adding the bonding strip to type AC armored cable.