Interesting article from U/L on armored cable

[Paul Tos]

Seen it glow on a test bench about 35 years ago in Electric 101 class. Forget the test parameters, but it does glow!

[Greg Fretwell]

Were they testing Federal Pacific breakers?

[Paul W. Abernathy]

Considering the number of FPE that are out on the market....probably a good chance greg is was....the known resistance per 100ft on the old BX is about 2.068 per 100ft....

It is over 2 X the resistance of todays AC cable and even higher in a normal conductor.

I simply do not believe a person should put their faith in old BX of pre-1960 and feel secure knowing the system itself is old...the breakers in the system are also probably as old.....and I am not alone in this concern.

Thats all......increased resistance( impedance ) is never a good thing when trying to clear a fault or if you have objectionable current issues in older homes because of DIYers doing something like trying to retro an older home with pre 1960 BX and make it appear to be a effective and low impedance system for the fault current...as always we can agree to disagree but atleast you keep it straight and to the point.........

The largest concern probably with OBJ is improperly done remote distribution panels and the incorrect bonding of which causes a big problem with a casing that is not designed for this intent. The advent of the bonding strip and better metals used helps reduce this risk.....thus why we still have MC and AC cable.....completly relavant issues.

Thanks for keepin it real.....

[Paul Tos]

No was simply was a high school teacher showing what can happen when Primative Pete shows up on the job.

Some things in life are grey, electricity is black and white, when grey shows up, many times it turns red (attributing to loss of life or limb and hopefully before it reaches that point it gets a RED TAG).