wiped disk - no longer bootable

[Gene Heskett]

On Thursday 11 July 2019 11:52:12 Ralf Mardorf via ubuntu-users wrote:

> On Thu, 11 Jul 2019 11:15:24 -0400, Gene Heskett wrote:
> >Well, me being both a retired tech, a C.E.T. and basicly a belt and
> >suspenders type in this regard, I also will be wearing a "ground me"
> >wrist band.  Those things are cheap enough, 2 or 3 bucks, that you
> >should always snap it on before touching what is today, nearly 100%
> >CMOS based circuitry. I also make heavy use of one of those $14 AC
> >sniffers. We still have in most pre-NEC built houses, and even in
> >stuff built 20 years post-NEC 3 pin electrical plugs that aren't
> >properly wired by incompetent carpenters.  You can get those gizmo's
> >from your nearest home center, electrical aisle.
> >
> >When I married this lady in '89, I moved into a house she'd bought
> >in '81. Since there weren't any children to consider, I took the 3rd,
> >smaller bedroom and made it into my computer den. First thing in the
> >next storm, blowed a modem.  Replaced it, blew it again. I took the
> >sockets out, verified they were wired right and soldered them with a
> >silver bearing solder, going all the way back to the service, found
> > it wasn't properly grounded and fixed that. That was 18 years ago,
> > and I haven't lost a single piece of gear since. I don't care if
> > lightning hits my service pole and sends me a quarter million volt
> > surge, but if everything is properly bonded so that everything
> > bounces in unison, nothing will be hurt.  I've since built a wired
> > workshed and a garage, that needed a new 200 amp service, so this
> > house is now a subcircuit. And I still seem to be safe.
>
> Old houses are an electric nightmare. I suffer from potential
> difference between one power outlet to another. Connect a grounded
> guitar amp to one power outlet and connect my single coil guitar with
> grounded strings and then touch the grounded metal case of my mixing
> console connected to another power outlet, while at the same time you
> touch the strings and have fun.
>
I don't call it fun, having yet the faint scars from electrical burns. 
But he wasn't ready for me so I am a survivor. It did trigger one hell 
of a case of the shingles though.

What you are describing is either a difference in polarity because the 
socket isn't wired right, possibly combined with one socket is on one 
leg of a 240 volt feed and the other socket is on the opposite leg.

You Ralf, I think, have more than enough smarts to figure out a way to 
test and fix that. On this side of the pond, the wider slot is supposed 
to be the neutral, and pretty close to ground. And the ONLY place where 
an ohmic connection between neutral and a real, rods driven a couple 
meters or more into the ground is in the entrance wiring. neutrals in a 
distribution box should be isolated from the box and its static grounds 
to the box, with the static ground carried to the box by a third 
separated conductor.  Here I suspect, we have a problem yet with color 
blind wire pullers.

The German equ to our NEC code may differ here and there but generally 
follows the same ideas I'd expect.  Its what works.

> Not to mention that when I worked for Brauner Microphones we had just
> one isolating transformer, most of the gear was directly connected to
> the power outlets and the RCCB was dimensioned for heavy agricultural
> gear, since the manufactory was a farm in the first place.
>
> Nowadays at home, I don't own a transformer for galvanic isolation at
> all, but at least the RCCB has got a sane value.

If the place is wired correctly, you should never need one.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>