I didn't see the hot nuetral were reversed..........cheerslook at the diagram the hot and neutral are reversed
I see it, but with the reversed wiring of the receptacle, the current flowing on the shield, would be what ever resistance of the shield is, no?It wasn't fault current, it was normal neutral current that was using the audio cable shield as a parallel path.
I've seen something very similar happen with an RS-232 connection where it actually burned up.
I tend to agree.That's a BS story.
Kinda figured that was the case. You see, old K&T was aluminum, and never that I've seen, was in a j-box. The electricians who installed it soldered splices and wrapped them with a friction tape. It was quite the skill to wrap and solder K&T back then.Old K&T wiring had all black insulation. The hot was black, the neutral was black, and there was no safety ground. To make it even more confusing, many times the (black) neutral was run to the switch for the lights. So unless you compared the voltage to an earth ground, it was really easy to get confused.
Later K&T wiring was sort of gray (neutral) and black (hot), but after 80 years of oxidation, everything looks like the same color. Again, it's very easy to get the hot and neutral reversed when connecting to K&T.
Of course, it's a code violation to do any sort of bootleg ground, or to tie into open K&T wiring at all. And you're supposed to convert any 2-wire receptacles to a 3-wire GFCI with an unconnected ground screw. Since a GFCI doesn't require a ground wire to operate at all, then the consumer is safe from shock. However, the receptacle is supposed to be marked as "No Ground" but I've never seen one marked like that other than my own installs. Maybe I haven't been looking hard enough.
Just how do you guys deal with "upgrades" to grounded receptacles in old buildings?