In a Dark Attic

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Pierre C Belarge

Pierre C Belarge

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We all run into some great stuff...:wink:

Not only is there no box, no ground path, but the copper conductor is exposed.:cool:

Look-nobox.jpg



Maybe you need a closer looksee, don't get too close :grin:
Look-nobox-crop.jpg
 
Dennis Alwon

Dennis Alwon

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iwire said:
Charlie my point was that old BX is not a grounding means ........ or at least should not be used as one.
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I thought AC cable was a grounding means are you saying the old stuff wasn't?

320.108 Equipment Grounding Conductor.
Type AC cable shall provide an adequate path for fault current as required by 250.4(A)(5) or (B)(4) to act as an equipment grounding conductor.
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augie47

augie47

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the "old" AC may have been a "Code" grounding path, but in reality the unbonded (as compared to todays AC) metal jacket became a heater. I used to say due to high resistance, but I think someone here corrected me and said it was inductance....either way the long path of the jacket made it heat..often to red....
 
Dennis Alwon

Dennis Alwon

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augie47 said:
the "old" AC may have been a "Code" grounding path, but in reality the unbonded (as compared to todays AC) metal jacket became a heater. I used to say due to high resistance, but I think someone here corrected me and said it was inductance....either way the long path of the jacket made it heat..often to red....
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So we are talking about ac cable before the aluminum wire was installed in it. Okay I get it.
 
C

crossman gary

Senior Member
Copperclad said:
A recipe for disaster, that scenario could easily get any tradesman, or homeowner, Killed
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And things like this have gotten people killed. I believe it was in San Antonio... an apprentice crawling in a tight spot in an attic, all hot and sweaty, crawling across a waterpipe, contacted an exposed hot wire, and he didn't make it out. A tragedy that could have been prevented with just a little bit of care.
 
iwire

iwire

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Massachusetts
BLACK4TRUCK said:
Bob..where did you read that info??
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I made it up. :grin:

Here is how I see it, As far as I know the old BX was never listed for grounding. I understand that the armor can turn red hot under ground fault conditions.

If you look at 250.118(8) you see that AC cable can be used as a grounding means per 320.108. But when we look at 320.100 we see that the old BX does not meet the NEC requirement to be used as AC cable.

So IMO if we go to a job that is all old AC cable and start changing the old two wire receptacles to new three wire receptacles you have now created an NEC violation.

In the past I have used it as a grounding means, if I had to again I would very likely install a GFCI breaker to prevent a low impedance ground fault from starting a fire.

This is strictly my own opinion. :smile:
 
augie47

augie47

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Armored Cable
Armored cable (type AC) or what it is more commonly referred to as, BX, was first listed in 1899 by the Sprague Electric Co. When it was first conceived there were two experimental versions of this product. One version was called ?AX? and the other was ?BX? with the ?X? standing for experimental. The latter or BX version was the method that eventually got produced and the name BX stuck.

Even as old as Bob is :smile:, he probably doesn;t still have his copy of the 1899 NEC to see if BX was an acceptable grounding means. :D
 
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