Yup, exactly. Bootleg grounds (and RPBGs in particular) are like rats. Where's there's one, you can probably find a lot more.I admire Mike's passion on this issue.
Seems there's something to it, it's just a little above my head. Where I live it's all newer homes (60's and newer), so I don't run into bootlegged grounds. Guess I forget the rest of the world has much older communities and people do bizarre things over the years.
So the situation would be a homeowner getting shocks from a receptacle (or device plugged into a receptacle). The electrician fixes the problem.. then does a quick walk through, checking other receptacles' ground pin for live power and a bad bootleg?
If I am not mistaken, that is a Klein NCVT-1Mike, what is red/green designation there?
Klein said:High intensity, bright green LED indicates the tester is operational and aids in illuminating the workspace.
When voltage is detected, a high intensity, bright red LED illuminates and a warning tone sounds.
Yup, that's what it is. Costs around $17 at Home Depot, a little less online.
That's correct. A 3-light plug-in tester won't tell you there's a reverse polarity if the ground is also hot. Seems crazy but true.What I don't understand is, one of those receptacles is suppose to be wired in reverse polarity. The plug in tester will not detect that because the ground HAS voltage on it ?
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.Still gotta question the wire to the receps, if you don't mind?
It's a house, over a hundred years old, with knob and tube wiring, with no ground with the wires, the color of the neutral wire had faded, and the junction box from long ago, had the wrong wires connected to it. This is what the electrician didn't know, because he didn't look for a miswired J-box?
I am close?
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?
I'm not sure how to respond to this. First of all, I'm not the guy in the studio with the damaged equipment. I'm an independent consultant to the pro-audio industry and a technical writer with 10,000 articles in print. The guy with the studio just happens to be one of the professors at the same university where I teach. I was writing this article last year and looking for real-world examples. Adam was a great example of what can go wrong.While you point out an interesting dilema on paper, it s clear to me, this actual problem never happened the way it was explained. It seems you two created a problem on paper...in theory..and then wrote up a solution for some reason.
Don't feel bad about it. Manufacturers who brought up the AFCI stuff did the same thing. First they found a problem on paper, then created a solution, and then forced everyone to believe them with their "err on the side of safety BS".
You should write an article on how the electrician who you blamed this problem on, used standard wire nuts to splice the K&T to copper pigtails, and how that burnt your studio down.